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Oregon State University
1.
Dickson, David J.
Influence of processing parameters on diffusion of divalent nickel in wet silica sol-gel monoliths.
Degree: MS, Materials Science, 2010, Oregon State University
URL: http://hdl.handle.net/1957/17401
► The diffusion of divalent nickel (Ni²⁺) from wet silica gels was investigated. Silica gel is gaining interest as an encapsulation matrix for biological components. The…
(more)
▼ The diffusion of divalent nickel (Ni²⁺) from wet silica gels was investigated.
Silica
gel is gaining interest as an encapsulation matrix for biological components.
The transport of biologically relevant species within the
gel is determined by the
structural characteristics of the
gel, which are in turn governed by synthesis
parameters. Gels were synthesized by an acid-base two step process from
tetraethoxysilane (TEOS) precursors. Organically modified siloxane precursors,
including methyltriethoxysilane (MTES), dimethyldiethoxysilane (DMDES),
trimethylethoxysilane (TMES), and ethyltriethoxysilane (ETES) were also used for
some samples at a concentration of 10 molar % of silicon. PEG200 was used as an
additive in some samples. Sample space covered a full factorial design of three water ratios during hydrolysis of 4:1, 10:1 and 20:1, three acid catalyst concentrations as a ratio of silicon to acid, including 1:0.005, 1:0.01, and 1:0.02, and four dilution ratios during gelation to yield gels with a final silica content of 40:1, 60:1, 80:1, and 100:1, moles of water to moles of silicon. This processing space was selected due to its relevance to applications in the encapsulation of biological components.
Using Ni²⁺ as a tracer due to its strong absorbance peak at 395 nm, diffusion
coefficients were calculated for all samples using both an analytical solution to Fick's
Law, appropriate for one-dimensional diffusion, and an exponential empirical
approximation. Estimates were calculated using Microsoft Solver and ANOVA in SAS.
It was found that the diffusion coefficient in TEOS gels ranged from approximately
1.4x10⁻¹⁰ m²s⁻¹ to 6.3x10⁻¹⁰ m²s⁻¹, with a mean of approximately 2.5x10⁻¹⁰ m²s⁻¹ corresponding to approximately 14% to 63% of D for Ni²⁺ in unconfined aqueous solution, estimated to be approximately 1x10⁻⁹ m²s⁻¹. The addition of 10 mol% ORMOSILS was found to have a small effect on the predicted value of the diffusion coefficient depending on silicon content. In samples with a final silicon content of 80:1, D was slightly decreased to approximately 2.0x10⁻¹⁰ m²s⁻¹, but in samples with a silicon content of 100:1, D was slightly increased to approximately 3.5x10⁻¹⁰ m²s⁻¹. Variations in hydrolysis ratio, acid catalyst content, and dilution ratio had relatively weak effects on overall diffusion rates of Ni²⁺ with the exception of a few anomalous samples which were either unstable or displayed some syneresis. It can be concluded that over this broad processing space, gels can be tailored to best suit the particular bioencapsulation application, altering the chemical environment for optimal performance with minimal variation in the diffusion transport of small cationic ions such as Ni²⁺.
Advisors/Committee Members: Yokochi, Alexandre F. T. (advisor), Gibbons, Brady J. (committee member).
Subjects/Keywords: silica sol-gel; Silica gel
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APA (6th Edition):
Dickson, D. J. (2010). Influence of processing parameters on diffusion of divalent nickel in wet silica sol-gel monoliths. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/17401
Chicago Manual of Style (16th Edition):
Dickson, David J. “Influence of processing parameters on diffusion of divalent nickel in wet silica sol-gel monoliths.” 2010. Masters Thesis, Oregon State University. Accessed April 18, 2021.
http://hdl.handle.net/1957/17401.
MLA Handbook (7th Edition):
Dickson, David J. “Influence of processing parameters on diffusion of divalent nickel in wet silica sol-gel monoliths.” 2010. Web. 18 Apr 2021.
Vancouver:
Dickson DJ. Influence of processing parameters on diffusion of divalent nickel in wet silica sol-gel monoliths. [Internet] [Masters thesis]. Oregon State University; 2010. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/1957/17401.
Council of Science Editors:
Dickson DJ. Influence of processing parameters on diffusion of divalent nickel in wet silica sol-gel monoliths. [Masters Thesis]. Oregon State University; 2010. Available from: http://hdl.handle.net/1957/17401

Rutgers University
2.
Tumuluri, Anirudh, 1995-.
Synthesis of borosilicate gels with phenyl modifications and its effects on proton conductivity.
Degree: MS, Materials Science and Engineering, 2019, Rutgers University
URL: https://rucore.libraries.rutgers.edu/rutgers-lib/61971/
► Silicon alkoxides with boron alkoxides or boric acid were used to prepare borosilicate xerogels. Nitric acid was used to promote the hydrolysis of the silicon…
(more)
▼ Silicon alkoxides with boron alkoxides or boric acid were used to prepare borosilicate xerogels. Nitric acid was used to promote the hydrolysis of the silicon alkoxides, tetraethylorthosilicate (TEOS) and phenyltriethoxysilane (PhTES). Triethyl borate (TEB) and boric acid were the source of boron in the gels. The compositions were: 85 wt. % TEOS - 15 wt. % TEB, 80 wt. % TEOS - 15 wt. % TEB - 5 wt. % PhTES, 75 wt. % TEOS - 15 wt. % TEB, 10 wt. % PhTES, 85 wt. % TEOS - 15 wt. % Boric Acid, 80 wt. % TEOS - 15 wt. % Boric Acid - 5 wt. % PhTES and 75 wt. % TEOS - 15 wt. % Boric Acid, 10 wt. % PhTES.
Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) were performed to investigate the loss of weight and heat flows in the gels as a function of temperature. The weight loss and the energy absorbed during the endothermic peak decreased with the increasing PhTES content. Gels made from TEB show lower weight losses and enthalpy changes compared to similar gels made from boric acid.
X-Ray Diffraction was performed for phase identification and to determine the amount of crystallinity in the gels. The diffraction patterns contained peaks that were attributed to boric acid precipitates, which occurred in all the gels. Increase in PhTES decreased the amount of crystallinity in the gels. Gels made from TEB show lower amounts of crystallinity compared to similar gels made from boric acid.
Moisture adsorption-desorption was performed to investigate the water retention capabilities of the gels. The increases in PhTES content decreased the water retained in the gels. Adsorption values of the gels made from TEB and boric acid are comparable, but the mass loss due to desorption are higher for the gels synthesized from boric acid.
Electrochemical Impedance Spectroscopy (EIS) was performed to measure the proton conductivity of the gels. The increase in PhTES content reduces the proton conductivity slightly. Proton conductivity is dependent on the number of protons and number of sites available for hopping of protons. The phenyl in PhTES decreased the number of protons and sites. Gels prepared from TEB show higher proton conductivity compared to same gels made from boric acid.
Advisors/Committee Members: Mann, Adrian (chair), KLEIN, LISA C (internal member), Garofalini, Stephen (internal member), Goel, Ashutosh (internal member), School of Graduate Studies.
Subjects/Keywords: Sol-gel process; Silica gel
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MLA ·
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APA (6th Edition):
Tumuluri, Anirudh, 1. (2019). Synthesis of borosilicate gels with phenyl modifications and its effects on proton conductivity. (Masters Thesis). Rutgers University. Retrieved from https://rucore.libraries.rutgers.edu/rutgers-lib/61971/
Chicago Manual of Style (16th Edition):
Tumuluri, Anirudh, 1995-. “Synthesis of borosilicate gels with phenyl modifications and its effects on proton conductivity.” 2019. Masters Thesis, Rutgers University. Accessed April 18, 2021.
https://rucore.libraries.rutgers.edu/rutgers-lib/61971/.
MLA Handbook (7th Edition):
Tumuluri, Anirudh, 1995-. “Synthesis of borosilicate gels with phenyl modifications and its effects on proton conductivity.” 2019. Web. 18 Apr 2021.
Vancouver:
Tumuluri, Anirudh 1. Synthesis of borosilicate gels with phenyl modifications and its effects on proton conductivity. [Internet] [Masters thesis]. Rutgers University; 2019. [cited 2021 Apr 18].
Available from: https://rucore.libraries.rutgers.edu/rutgers-lib/61971/.
Council of Science Editors:
Tumuluri, Anirudh 1. Synthesis of borosilicate gels with phenyl modifications and its effects on proton conductivity. [Masters Thesis]. Rutgers University; 2019. Available from: https://rucore.libraries.rutgers.edu/rutgers-lib/61971/

NSYSU
3.
Lee, Chia-an.
Structure and Morphology of Nanostructure Zinc Oxide Thin Films Prepared by Sol-Gel Methods.
Degree: Master, Electro-Optical Engineering, 2009, NSYSU
URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0720109-192609
► This research is preparing a Nanostructure zinc oxide thin films by sol-gel methods, we use spin coating method to coat the gel on the substrate,…
(more)
▼ This research is preparing a Nanostructure zinc oxide thin films by
sol-
gel methods, we use spin coating method to coat the
gel on the substrate, and then put the substrate from 100°C -500°C for 10 min after each coating. We change the concentration of
sol-gelãadd dispersing agents and change the temperature of heat treatment to confer structure and morphology of nanostructure zinc oxide thin film. Through the experimentation we can know when the concentration of
sol-
gel become low, the film properties of zinc oxide thin films will become bad. And the thickness of zinc oxide thin films will become thick with increasing the concentration of
sol-
gel.And adding appropriate dispersing agents will become different morphology of ZnO thin film surface, on the other side, when the different temperature of heat treatment, the nature of crystalãroughness of the surface and photoelectric character will change.
Then we accede AmAc to
sol-
gel solution will dope n ion into the ZnO thin film, and the thin film with doping n ion has better electric characteristic than without doping. In the end, we Prepare ZnO thin film to apply as thin film transistor, we can make a p-type channel TFT successfully. TFT's critical voltage is -0.72V,carrier mobility is 0.29 cm2/Vs and On/Off ratio is 1.1E4.
Advisors/Committee Members: Hsin-Lung Chen (chair), Ping-Tsung Huang (chair), Yu-Kai Han (chair), Wen-Yao Huang (committee member), Ann-Kuo Chu (chair).
Subjects/Keywords: ZnO; Sol-Gel
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Lee, C. (2009). Structure and Morphology of Nanostructure Zinc Oxide Thin Films Prepared by Sol-Gel Methods. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0720109-192609
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Lee, Chia-an. “Structure and Morphology of Nanostructure Zinc Oxide Thin Films Prepared by Sol-Gel Methods.” 2009. Thesis, NSYSU. Accessed April 18, 2021.
http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0720109-192609.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Lee, Chia-an. “Structure and Morphology of Nanostructure Zinc Oxide Thin Films Prepared by Sol-Gel Methods.” 2009. Web. 18 Apr 2021.
Vancouver:
Lee C. Structure and Morphology of Nanostructure Zinc Oxide Thin Films Prepared by Sol-Gel Methods. [Internet] [Thesis]. NSYSU; 2009. [cited 2021 Apr 18].
Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0720109-192609.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Lee C. Structure and Morphology of Nanostructure Zinc Oxide Thin Films Prepared by Sol-Gel Methods. [Thesis]. NSYSU; 2009. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0720109-192609
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

NSYSU
4.
Lin, Shu-Ching.
Investigation on the ZnO Thin Film for Optoelectronic Device Application.
Degree: Master, Electro-Optical Engineering, 2008, NSYSU
URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0122108-062049
► In recent years, transparent and conductive layers of some metallic oxide, such as cadmium oxide, indium oxide, tin oxide and zinc oxide, can be used…
(more)
▼ In recent years, transparent and conductive layers of some metallic oxide, such as cadmium oxide, indium oxide, tin oxide and zinc oxide, can be used for semiconducting transparent coatings. Transparent electronics are nowadays a crucial technology for the next generation of optoelectronic devices.
Zinc oxide (ZnO) is a II-VI compound semiconductor with a wide direct bandgap of 3.37 eV. Therefore, ZnO based transparent thin film transistors (TFTs) have been studied extensively. For the wide variety of applications, numerous ZnO films preparation methods have been attempted. In this thesis, the devices of ZnZrO active channel layers were fabricated by the
sol-
gel spin-coating method. These ZnZrO TFTs were fabricated by bottom-gate bottom-contact-type TFTs.
The Experimental results have shown that the electrical properties of the ZnZrO TFTs are strongly dependent on visible light and ambient oxygen. In addition, in this study, the results concerning the influence of temperature on the electrical properties of ZnZrO TFTs also have been discussed. Finally, except for the application of switch devices, the ZnZrO TFTs by
sol-
gel spin-coating process exhibits a potential application for gas sensors.
Advisors/Committee Members: An-Kuo Chu (chair), Ting-Chang Chang (committee member), Jung-Fang Chang (chair), Cheng-Tung Huang (chair).
Subjects/Keywords: Znic Oxide; ZnO; sol-gel
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Lin, S. (2008). Investigation on the ZnO Thin Film for Optoelectronic Device Application. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0122108-062049
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Lin, Shu-Ching. “Investigation on the ZnO Thin Film for Optoelectronic Device Application.” 2008. Thesis, NSYSU. Accessed April 18, 2021.
http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0122108-062049.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Lin, Shu-Ching. “Investigation on the ZnO Thin Film for Optoelectronic Device Application.” 2008. Web. 18 Apr 2021.
Vancouver:
Lin S. Investigation on the ZnO Thin Film for Optoelectronic Device Application. [Internet] [Thesis]. NSYSU; 2008. [cited 2021 Apr 18].
Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0122108-062049.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Lin S. Investigation on the ZnO Thin Film for Optoelectronic Device Application. [Thesis]. NSYSU; 2008. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0122108-062049
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Alberta
5.
Song, Lidan.
Improving the photostability of aramid fabric by sol-gel
coating.
Degree: MS, Department of Human Ecology, 2011, University of Alberta
URL: https://era.library.ualberta.ca/files/73666503s
► Limited studies have shown effective ways to protect aramid fabrics from photodegradation. The purpose of this research is to find an effective and feasible method…
(more)
▼ Limited studies have shown effective ways to protect
aramid fabrics from photodegradation. The purpose of this research
is to find an effective and feasible method to improve the
photostability of Nomex® aramid fabric. An inorganic titanium
dioxide sol-gel is used as a UV-protective coating on the fabric
surface. The effectiveness of the sol-gel coating in preventing
photodegradation is determined by examining changes in mechanical
properties, chemical composition, as well as surface morphology
structure of the coating. Findings show that nano scale anatase
titanium dioxide thin films were formed on the fabric surface and
decreased the photodegradation rate of the Nomex® aramid
fabric.
Subjects/Keywords: Aramid; Sol-gel; Photodegradation
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Song, L. (2011). Improving the photostability of aramid fabric by sol-gel
coating. (Masters Thesis). University of Alberta. Retrieved from https://era.library.ualberta.ca/files/73666503s
Chicago Manual of Style (16th Edition):
Song, Lidan. “Improving the photostability of aramid fabric by sol-gel
coating.” 2011. Masters Thesis, University of Alberta. Accessed April 18, 2021.
https://era.library.ualberta.ca/files/73666503s.
MLA Handbook (7th Edition):
Song, Lidan. “Improving the photostability of aramid fabric by sol-gel
coating.” 2011. Web. 18 Apr 2021.
Vancouver:
Song L. Improving the photostability of aramid fabric by sol-gel
coating. [Internet] [Masters thesis]. University of Alberta; 2011. [cited 2021 Apr 18].
Available from: https://era.library.ualberta.ca/files/73666503s.
Council of Science Editors:
Song L. Improving the photostability of aramid fabric by sol-gel
coating. [Masters Thesis]. University of Alberta; 2011. Available from: https://era.library.ualberta.ca/files/73666503s

University of Alberta
6.
Adl, Ahmad H.
Synthesis and Characterization of Solution Processed ZnO
Thin Films.
Degree: PhD, Department of Electrical and Computer
Engineering, 2016, University of Alberta
URL: https://era.library.ualberta.ca/files/c1n79h445n
► Recently ZnO has drawn a lot of attention in semiconductor industry due to its interesting features. High exciton binding energy, high resistivity against radiation, high…
(more)
▼ Recently ZnO has drawn a lot of attention in
semiconductor industry due to its interesting features. High
exciton binding energy, high resistivity against radiation, high
breakdown voltage, insensitivity to visible light, and easy wet
chemical etching are some of the interesting features of this
material. ZnO materials can be deposited using two ways: vacuum
deposition and solution processing methods. The ZnO thin films
deposited using vacuum deposition offer better crsytallinity and
hence electrical performance. The main drawback of vacuum
deposition is the requirement of expensive vacuum pumps.
Additionally the throughput of this method is less compared to
solution-processed methods. Solution processing offers a cheap easy
method of ZnO thin film deposition. Currently two solution
processing methods are used: pyrolysis of a coated film of a
solution-based ZnO precursor (usually zinc acetate) and the
spin-coating of a colloidal dispersion of ZnO nanoparticles,
subsequently subjected to sintering. In both these methods, it is
difficult to control the electrical parameters of the films such as
the doping density and defect concentration from run to run, and
p-type ZnO is not yet reproducibly obtainable. Therefore, better
methods to control the electrical characteristics of the FETs
incorporating ZnO films are much needed. The properties of the
semiconductor film have a huge impact on the electrical performance
of the ZnO TFTs. Hence by reducing the number of defects high
performance ZnO TFTs will be obtained. Another method of improving
the TFT performance is by modifying the transistor structure. One
method of modifying the transistor structure is through schottky
barrier thin film transistor (SB-TFT) or the source gated
transistor (SGT). In the first part of the thesis we will study the
effect of Schottky source contact on the enhancement of the
electrical properties of thin film transistors. The sol stabilizer
used in the solution processing of ZnO functions variously as a sol
homogenizer, chelating agent, wettability improver and capping
agent. In spite of its obvious importance to influencing ZnO film
properties, the effect of the sol stabilizer has not been
systematically studied and is generally unknown. Although there are
a few papers examining different stabilizers, these studies have
been mainly restricted to alkaline short chain ligand bearing
species such as ethanolamine, diethanolamine, triethanolamine, etc.
Furthermore, these prior reports did not examine the effect of the
stabilizers on the performance of the resulting ZnO thin films in
optoelectronic devices. Our study also examines longer chain and
acidic stabilizers such as oleic acid, oleylamine and octadecene,
which are used extensively in the synthesis of colloidal II-VI
quantum dots, but have not been used to form ZnO thin films. We
examined the effect of six different sol stabilizers
-triethylamine, oleylamine, oleic acid, octadecene, triethanolamine
and ethanolamine (along with a sol without any stabilizer), on the
grain size, crystallographic…
Subjects/Keywords: ZnO; sol-gel; thin films
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Adl, A. H. (2016). Synthesis and Characterization of Solution Processed ZnO
Thin Films. (Doctoral Dissertation). University of Alberta. Retrieved from https://era.library.ualberta.ca/files/c1n79h445n
Chicago Manual of Style (16th Edition):
Adl, Ahmad H. “Synthesis and Characterization of Solution Processed ZnO
Thin Films.” 2016. Doctoral Dissertation, University of Alberta. Accessed April 18, 2021.
https://era.library.ualberta.ca/files/c1n79h445n.
MLA Handbook (7th Edition):
Adl, Ahmad H. “Synthesis and Characterization of Solution Processed ZnO
Thin Films.” 2016. Web. 18 Apr 2021.
Vancouver:
Adl AH. Synthesis and Characterization of Solution Processed ZnO
Thin Films. [Internet] [Doctoral dissertation]. University of Alberta; 2016. [cited 2021 Apr 18].
Available from: https://era.library.ualberta.ca/files/c1n79h445n.
Council of Science Editors:
Adl AH. Synthesis and Characterization of Solution Processed ZnO
Thin Films. [Doctoral Dissertation]. University of Alberta; 2016. Available from: https://era.library.ualberta.ca/files/c1n79h445n

Texas A&M University
7.
Waetzig, Gregory Ryan.
Accessing Metastable Solid-Solution Nanoparticles from Solution-Phase Condensation Reactions: Applications in High-K Dielectrics, Geopolymerization, and X-Ray Phosphors.
Degree: PhD, Chemistry, 2018, Texas A&M University
URL: http://hdl.handle.net/1969.1/173388
► This dissertation focuses on the design, synthesis, and functional applications of ceramic materials prepared with precise compositional, dimensional, and structural control from molecular precursors using…
(more)
▼ This dissertation focuses on the design, synthesis, and functional applications of ceramic materials prepared with precise compositional, dimensional, and structural control from molecular precursors using a versatile sol—
gel condensation process. Three primary thrusts have stemmed from this central idea: (i) mapping the size-dependent phase diagram of HfOv2 and stabilizing the metastable tetragonal phase of HfOv2 at room temperature as a result of dimensional confinement, thereby obtaining a technologically important high-dielectric-constant polymorph that is only accessible above a temperature of 1720°C in the bulk; (ii) developing a method to cross-link plant fibers through creation of siloxane frameworks, resulting in the stabilization of a mechanically resilient load-bearing composite for roadworks in the Alberta Oil Sands; and (iii) stabilizing solid-solution rare earth oxychloride (REOCl) nanocrystals across a broad compositional range to obtain a full palette of X-ray phosphors, allowing for elucidation of activation channels, sensitization mechanisms, and recombination pathways underpinning X-ray-activated optical luminescence.
The dissertation develops a versatile synthetic toolbox for defining oxide and oxyhalide frameworks. The choice of molecular precursors and ligands added during synthesis strongly influence kinetics of particle growth and allow for compositional control as well as tunability of particle dimensions. The metastable materials synthesized in this work have allowed for exploration of the size-dependent phase diagram of HfO2 and have enabled the development of quaternary and quintary solid-solution phosphors based on the PbFCl-type LaOCl and GdOCl frameworks.
Advisors/Committee Members: Banerjee, Sarbajit (advisor), Clearfield, Abraham (committee member), Son, Dong Hee (committee member), Grunlan, Jamie (committee member).
Subjects/Keywords: metastable; sol-gel synthesis; phosphors
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Waetzig, G. R. (2018). Accessing Metastable Solid-Solution Nanoparticles from Solution-Phase Condensation Reactions: Applications in High-K Dielectrics, Geopolymerization, and X-Ray Phosphors. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/173388
Chicago Manual of Style (16th Edition):
Waetzig, Gregory Ryan. “Accessing Metastable Solid-Solution Nanoparticles from Solution-Phase Condensation Reactions: Applications in High-K Dielectrics, Geopolymerization, and X-Ray Phosphors.” 2018. Doctoral Dissertation, Texas A&M University. Accessed April 18, 2021.
http://hdl.handle.net/1969.1/173388.
MLA Handbook (7th Edition):
Waetzig, Gregory Ryan. “Accessing Metastable Solid-Solution Nanoparticles from Solution-Phase Condensation Reactions: Applications in High-K Dielectrics, Geopolymerization, and X-Ray Phosphors.” 2018. Web. 18 Apr 2021.
Vancouver:
Waetzig GR. Accessing Metastable Solid-Solution Nanoparticles from Solution-Phase Condensation Reactions: Applications in High-K Dielectrics, Geopolymerization, and X-Ray Phosphors. [Internet] [Doctoral dissertation]. Texas A&M University; 2018. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/1969.1/173388.
Council of Science Editors:
Waetzig GR. Accessing Metastable Solid-Solution Nanoparticles from Solution-Phase Condensation Reactions: Applications in High-K Dielectrics, Geopolymerization, and X-Ray Phosphors. [Doctoral Dissertation]. Texas A&M University; 2018. Available from: http://hdl.handle.net/1969.1/173388

Clemson University
8.
Hill, Laura.
Novel Light Emissive Yttrium-Based Nanoparticles and Composites.
Degree: PhD, Materials Science and Engineering, 2014, Clemson University
URL: https://tigerprints.clemson.edu/all_dissertations/1355
► Yttrium-based inorganic optical materials generally are of practical interest for three applications: solid state lighting/displays, lasers, and scintillators. Solid-state lighting is particularly desirable commercially…
(more)
▼ Yttrium-based inorganic optical materials generally are of practical interest for three applications: solid state lighting/displays, lasers, and scintillators. Solid-state lighting is particularly desirable commercially for its efficiency and lifetime compared to traditional incandescent alternatives. This type of lighting technology is of increasing interest as incandescent light bulbs are being gradually phased-out due to government regulations on maximum wattage of these devices. Additionally, shortcomings in the current state of the art have driven the need for a more thermally stable material for use in this area. In this dissertation, we develop and characterize a novel composite material consisting of optically active yttrium-based nanoparticles doped into silica
sol-gels. For lighting and display applications, low-cost, low-temperature synthesis methods for materials that meet or exceed the quality of the materials currently on the market are highly desirable. During the course of this work, we discuss the characterization of yttrium-based nanoparticles with respect to their incorporation in a
sol-
gel matrix composite. We then prepared these composite materials using a variety of methods and assess their quality according to a set of selection criteria and for lighting/display applications. Novel light-emitting composites consisting of Ce:YAG or Eu:Y2O3 (yttria) nanoparticles in an inorganic medium were successfully developed and characterized. The optical properties of the nanoparticles were maintained when incorporated into the
sol-
gel medium and were shown to be comparable with the current state of the art. Comparison was made between the nanoparticle emission and the composite emission and, in the case of the Ce:YAG, the CIE coordinates, showing no change between the emission intensities or peak locations. We successfully demonstrated the conversion of fluoride-based particles into Y2O3 during
sol-
gel processing and demonstrated that no reaction took place between the nanoparticles and the
sol-
gel medium. Stability of nanoparticles in suspension was overcome through the control of pH during
sol-
gel synthesis. Through both base- and/or acid-catalysis, we produced optically active nanoparticle doped
sol-
gel composites containing YAG and Yttria. Our results indicated no detrimental effect on the nanoparticles upon incorporation into the
sol-
gel matrix; this was demonstrated through XRD, where no silicate phases were observed, through EDX, where we saw no diffusion of yttrium into the
sol-
gel and no silicon diffusing into the nanoparticles, and through photoluminescence, where emissions were consistent with that of the as-made nanoparticles. These results led us to theorize that the nanoparticles, rather than being bonded to the matrix, are seated in the void space that is prevalent in
sol-
gel systems. Additionally, these materials are stable at much higher temperatures than current resin-based systems.
Advisors/Committee Members: John Ballato, Philip Brown, O. Thompson Mefford, Eric Skaar.
Subjects/Keywords: composites; nanoparticles; optics; sol-gel
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
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APA (6th Edition):
Hill, L. (2014). Novel Light Emissive Yttrium-Based Nanoparticles and Composites. (Doctoral Dissertation). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_dissertations/1355
Chicago Manual of Style (16th Edition):
Hill, Laura. “Novel Light Emissive Yttrium-Based Nanoparticles and Composites.” 2014. Doctoral Dissertation, Clemson University. Accessed April 18, 2021.
https://tigerprints.clemson.edu/all_dissertations/1355.
MLA Handbook (7th Edition):
Hill, Laura. “Novel Light Emissive Yttrium-Based Nanoparticles and Composites.” 2014. Web. 18 Apr 2021.
Vancouver:
Hill L. Novel Light Emissive Yttrium-Based Nanoparticles and Composites. [Internet] [Doctoral dissertation]. Clemson University; 2014. [cited 2021 Apr 18].
Available from: https://tigerprints.clemson.edu/all_dissertations/1355.
Council of Science Editors:
Hill L. Novel Light Emissive Yttrium-Based Nanoparticles and Composites. [Doctoral Dissertation]. Clemson University; 2014. Available from: https://tigerprints.clemson.edu/all_dissertations/1355

University of New South Wales
9.
Du, Jianhao.
Synthesis of KBNNO thin film by sol-gel method and its modification.
Degree: Materials Science & Engineering, 2020, University of New South Wales
URL: http://handle.unsw.edu.au/1959.4/70060
;
https://unsworks.unsw.edu.au/fapi/datastream/unsworks:71692/SOURCE02?view=true
► Since the first industrial revolution, fossil fuels have been used in different areas for mass production. However, the use of fossil fuels can cause damage…
(more)
▼ Since the first industrial revolution, fossil fuels have been used in different areas for mass production. However, the use of fossil fuels can cause damage to the environment due to the emission of greenhouse gases or other toxic pollutants, which pose a threat to the environment. Moreover, higher fossil fuel consumption leads to less reserve and thus makes it difficult to satisfy energy demands in the future. Solar energy, as a renewable energy, has been widely used in many rural areas for the generation of local electricity. However, large-scale use of solar plants remains a thorny issue owing to their high manufacturing costs. Currently, most commercial solar cells are made of high purity silicon. This process requires massive energy consumption. Compared with traditional solar cells, perovskite oxide has attracted attention from scientists because of its increased efficiency and relatively low cost. Perovskite oxide can provide an opportunity for the large-scale production of solar cells, which could alleviate the energy crisis in the future. In this project, Barium and Nickel co-doped Potassium niobium oxides [KNbO3]1- [BaNi1/2Nb1/2O3-] (KBNNO, x=0.1, 0.2, 0.3, 0.4, 0.5) were investigated. The
sol-
gel method was applied for the KBNNO precursor configuration, and the KBNNO thin film was deposited by spin coating. Several routes were used for precursor optimisation. After deposition, organic pyrolysis and metal oxide crystallisation were accomplished through heat treatment. All samples were deposited on Pt/SiO2/Si, while Pt was used as the bottom electrode in the PV measurement section. At x=0.1, images from AFM showed that the smoothest thin film was obtained when the spin coating speed was 4000 rpm. SEM and XRD were used for structural characterisation. EDS was applied to confirm the elements on the specimens. A bandgap measurement was performed by UV-vis-Nir and was extrapolated by the Tauc method. At x=0.1, the lowest bandgap was obtained at 1.76 eV due to Ni-VO-Nb bonding. When the amount of doping was increased, more nickel ions facilitated the bonding change from Ni-VO-Nb to Ni-VO-Ni, contributing to a higher bandgap. The photovoltaic effect was also observed from KBNNO from x=0.1 to 0.3.
Advisors/Committee Members: Wang, Danyang, Materials Science & Engineering, Faculty of Science, UNSW.
Subjects/Keywords: Photovoltaic performance; Perovskite; Sol-gel
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Du, J. (2020). Synthesis of KBNNO thin film by sol-gel method and its modification. (Masters Thesis). University of New South Wales. Retrieved from http://handle.unsw.edu.au/1959.4/70060 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:71692/SOURCE02?view=true
Chicago Manual of Style (16th Edition):
Du, Jianhao. “Synthesis of KBNNO thin film by sol-gel method and its modification.” 2020. Masters Thesis, University of New South Wales. Accessed April 18, 2021.
http://handle.unsw.edu.au/1959.4/70060 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:71692/SOURCE02?view=true.
MLA Handbook (7th Edition):
Du, Jianhao. “Synthesis of KBNNO thin film by sol-gel method and its modification.” 2020. Web. 18 Apr 2021.
Vancouver:
Du J. Synthesis of KBNNO thin film by sol-gel method and its modification. [Internet] [Masters thesis]. University of New South Wales; 2020. [cited 2021 Apr 18].
Available from: http://handle.unsw.edu.au/1959.4/70060 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:71692/SOURCE02?view=true.
Council of Science Editors:
Du J. Synthesis of KBNNO thin film by sol-gel method and its modification. [Masters Thesis]. University of New South Wales; 2020. Available from: http://handle.unsw.edu.au/1959.4/70060 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:71692/SOURCE02?view=true

Rutgers University
10.
Matuk, Adeal Sobhe.
Titania-silica sol-gel coatings on glass.
Degree: PhD, Materials Science and Engineering, 2018, Rutgers University
URL: https://rucore.libraries.rutgers.edu/rutgers-lib/59167/
► Binary TiO2-SiO2 oxides are materials that have attracted attention due to their usefulness as heterogeneous catalysts and catalytic supports. Due to the large difference between…
(more)
▼ Binary TiO2-SiO2 oxides are materials that have attracted attention due to their usefulness as heterogeneous catalysts and catalytic supports. Due to the large difference between their optical properties, in particular, band gap and refractive index, and their compatibility with respect to the deposition conditions, SiO2 and TiO2 appear well suited for these purposes. These materials have been synthesized by several techniques including chemical vapor deposition, sputtering and
sol-
gel. The
sol-
gel process is a versatile method to control the thickness, uniformity and thermal stability of high surface area materials. The
sol-
gel method presents many advantages such as utilization of simple equipment, high homogeneity and the possibility of using a variety of substrates of different sizes.
This thesis investigates the preparation of glass coatings from TiO2-SiO2 and Fe-doped TiO2-SiO2 by using the low-temperature
sol-
gel process. The TiO2-SiO2
sol was prepared from titanium (IV) butoxide Ti(OCH2CH2CH2CH3)4, and tetraethylorthosilicate (TEOS), (Si (OC2H5)4). The steps involved in the fabrication of
sol-
gel derived thin films, such as
sol preparation and substrate preparation are discussed. Physical and chemical characterization of the thin films are discussed in detail. UV-Visible spectroscopy, Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) were used to measure transmittance, thickness of films, the identification of phases, and chemical structure.
Eleven different compositions, 3, 5, 7.9, 10, and 15% TiO2, and iron (Fe) doped TiO2- SiO2 were investigated. Films with five compositions of SiO2-TiO2 were coated onto glass microscope slides using dip-coating method. Thin films in this study were subjected to heat treatment in a furnace at 100ºC for 24 hours. The samples with 1 and 3 dip-coatings of 10% TiO2-90% SiO2 and 15% TiO2-85% SiO2 with solution age 0, 5, 15, and 25 days exhibit higher transmittance than any of the other compositions, especially in the spectral region 400-600nm. Since the peak of the solar radiation spectrum lies in this important spectral region, the optical performance of these samples is promising, and these samples were studied further. Transmission spectra for different amounts of Fe(NO3)3 doped TiO2-SiO2 thin films show that the films with smaller amounts of Fe(NO3)3 0.0001 % exhibited higher transmittance in the spectral region 450nm - 550nm. This dopant amount has negligible absorption. Also, the transmittance of the as-deposited films at 0 days for all layers 1 and 3 is higher than the transmittance of the films for the solution aged 25 days. The solution should not be aged, if practical. The thickness of films with 1 and 3 coatings on the glass substrate were measured in fresh and aged solutions. The results of thickness measurements are in agreement with the transmittance measurement results.
Based on XRD analysis, the synthesized powders are amorphous. No characteristic crystalline peaks are observed. …
Advisors/Committee Members: KLEIN, LISA C (chair), School of Graduate Studies.
Subjects/Keywords: Sol-gel process; Glass coatings
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Matuk, A. S. (2018). Titania-silica sol-gel coatings on glass. (Doctoral Dissertation). Rutgers University. Retrieved from https://rucore.libraries.rutgers.edu/rutgers-lib/59167/
Chicago Manual of Style (16th Edition):
Matuk, Adeal Sobhe. “Titania-silica sol-gel coatings on glass.” 2018. Doctoral Dissertation, Rutgers University. Accessed April 18, 2021.
https://rucore.libraries.rutgers.edu/rutgers-lib/59167/.
MLA Handbook (7th Edition):
Matuk, Adeal Sobhe. “Titania-silica sol-gel coatings on glass.” 2018. Web. 18 Apr 2021.
Vancouver:
Matuk AS. Titania-silica sol-gel coatings on glass. [Internet] [Doctoral dissertation]. Rutgers University; 2018. [cited 2021 Apr 18].
Available from: https://rucore.libraries.rutgers.edu/rutgers-lib/59167/.
Council of Science Editors:
Matuk AS. Titania-silica sol-gel coatings on glass. [Doctoral Dissertation]. Rutgers University; 2018. Available from: https://rucore.libraries.rutgers.edu/rutgers-lib/59167/

Brunel University
11.
Boughton, Edward.
A screen printed carbon nanotube-based field emission device.
Degree: PhD, 2017, Brunel University
URL: http://bura.brunel.ac.uk/handle/2438/15036
;
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.824282
► Field emission devices have the potential to replace thermionic cathode electron sources in x-ray scanners and microwave devices. This study aims to exploit the high…
(more)
▼ Field emission devices have the potential to replace thermionic cathode electron sources in x-ray scanners and microwave devices. This study aims to exploit the high aspect ratio, small size and ballistic conductivity of carbon nanotubes (CNTs) to produce a field emission cathode with high current density and low turn-on field. A method of screen-printing CNT-containing inks has been developed and used to fabricate field emission cathodes on a variety of substrates. Increases in emission current density have been achieved by optimisation of CNT concentration and selection of CNT species. The device has the advantage over thermionic cathodes of requiring fewer connections, has no warm-up time and can be fabricated on several substrate materials. Additionally, a test setup has been developed to evaluate the performance of field emission devices capable of delivering high current densities in a diode configuration, featuring an adjustable anode-cathode gap, a current limiting resistor and the option of a phosphor-coated glass anode to assess emitter uniformity.
Subjects/Keywords: Screen printing; Sol-gel
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Boughton, E. (2017). A screen printed carbon nanotube-based field emission device. (Doctoral Dissertation). Brunel University. Retrieved from http://bura.brunel.ac.uk/handle/2438/15036 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.824282
Chicago Manual of Style (16th Edition):
Boughton, Edward. “A screen printed carbon nanotube-based field emission device.” 2017. Doctoral Dissertation, Brunel University. Accessed April 18, 2021.
http://bura.brunel.ac.uk/handle/2438/15036 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.824282.
MLA Handbook (7th Edition):
Boughton, Edward. “A screen printed carbon nanotube-based field emission device.” 2017. Web. 18 Apr 2021.
Vancouver:
Boughton E. A screen printed carbon nanotube-based field emission device. [Internet] [Doctoral dissertation]. Brunel University; 2017. [cited 2021 Apr 18].
Available from: http://bura.brunel.ac.uk/handle/2438/15036 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.824282.
Council of Science Editors:
Boughton E. A screen printed carbon nanotube-based field emission device. [Doctoral Dissertation]. Brunel University; 2017. Available from: http://bura.brunel.ac.uk/handle/2438/15036 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.824282
12.
Caldas, Elisângela Muncinelli.
Desenvolvimento de sílicas organofuncionalizadas para aplicação como sensores eletroquímicos.
Degree: 2014, Brazil
URL: http://hdl.handle.net/10183/116452
► Neste trabalho foram sintetizados dois diferentes materiais híbridos à base de sílica para serem aplicados no desenvolvimento de sensores eletroquímicos. O primeiro trata de sílica…
(more)
▼ Neste trabalho foram sintetizados dois diferentes materiais híbridos à base de sílica para serem aplicados no desenvolvimento de sensores eletroquímicos. O primeiro trata de sílica mesoporosa modificada por uma reação de enxerto com silsesquioxano iônico contendo o grupo cloreto de 1,4-diazoniabiciclo[2,2,2]octano. Esse material, denominado (Db/Sílica), contém o silsesquioxano altamente disperso na superfície da sílica e foi utilizado como modificador de eletrodo de pasta de carbono para determinação de metil paration. Espectroscopia no infravermelho, análise elementar e isotermas de adsorção e dessorção de N2 foram utilizadas para a caracterização do material. O comportamento eletroquímico do metil paration foi avaliado por voltametria cíclica e voltametria de pulso diferencial. A faixa de resposta linear do metil paration foi entre 1,25 × 10-7 e 2,56 × 10-6 mol L-1, em solução tampão Britton- Robinson (BR) em pH 6,0. O limite de detecção e a
sensibilidade do eletrodo contendo Db/Sílica foram estimados em 0,013 μmol L-1 e 6,3 μA μmol L-1. A segunda proposta trata da síntese, via método
sol-
gel, de três matrizes carbono cerâmicos. O resultado foi a obtenção de três matrizes mesoporosas denominadas SG1, SG2 e SG3 com máximos de distribuição de tamanho de poros em 7, 14 e 21 nm, respectivamente. As matrizes foram modificadas covalentemente com 3-aminopropiltrimetoxisilano (APTMS), glutaraldeído (GA) e com a enzima Glicose Oxidase (GOx). As matrizes e os materiais resultantes das modificações foram caracterizados por isotermas de adsorção e dessorção de N2, análise termogravimétrica e quantificação espectrofométrica de proteína pelo método de Bradford. Os materiais modificados foram utilizados na forma de discos para confecção de eletrodos carbono cerâmicos e seu comportamento eletroquímico avaliado inicialmente por voltametria cíclica. O material modificado em que foi utilizada a matriz com maior tamanho de poros,
SG3/AP/GA/GOx, apresentou melhor resposta de corrente para a imobilização da enzima quando comparado aos outros dois suportes. Desta forma, esse material foi caracterizado por microscopia eletrônica de varredura (MEV) e por espectroscopia de dispersão de elétrons (EDS) e avaliado como biossensor para glicose por cronoamperometria. A faixa de resposta linear do biossensor foi entre 0,39 e 5,36 mmol L-1 de glicose, em atmosfera de gás argônio. A sensibilidade e o limite de detecção do eletrodo carbono cerâmico nesta atmosfera foram estimados em 0,33 μA mM-1 cm-2 e 0,93 mmol L-1, respectivamente. A a constante de Michaelis-Menten (KM) estimada em 1,27 mmol L-1 e a corrente máxima de saturação (iss) em 0,59 μA. O eletrodo carbono cerâmico SG3/AP/GA/GOx, avaliado em atmosfera saturada de O2, apresentou resposta linear na faixa de concentração de glicose entre 0,2 e 2,47 mmol L-1. A sensibilidade e o limite de detecção foram estimados em 4,44 μA mM-1 cm-2 e 0,26 mmol L-1 respectivamente,
KM 0,52 mmol L-1 e iss 3,12 μA. Esses resultados mostram que os materiais Db/Sílica e SG3/AP/GA/GOx apresentam potencialidade…
Advisors/Committee Members: Benvenutti, Edilson Valmir.
Subjects/Keywords: Silsesquioxanos; Sílica; Sol-gel
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Caldas, E. M. (2014). Desenvolvimento de sílicas organofuncionalizadas para aplicação como sensores eletroquímicos. (Doctoral Dissertation). Brazil. Retrieved from http://hdl.handle.net/10183/116452
Chicago Manual of Style (16th Edition):
Caldas, Elisângela Muncinelli. “Desenvolvimento de sílicas organofuncionalizadas para aplicação como sensores eletroquímicos.” 2014. Doctoral Dissertation, Brazil. Accessed April 18, 2021.
http://hdl.handle.net/10183/116452.
MLA Handbook (7th Edition):
Caldas, Elisângela Muncinelli. “Desenvolvimento de sílicas organofuncionalizadas para aplicação como sensores eletroquímicos.” 2014. Web. 18 Apr 2021.
Vancouver:
Caldas EM. Desenvolvimento de sílicas organofuncionalizadas para aplicação como sensores eletroquímicos. [Internet] [Doctoral dissertation]. Brazil; 2014. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/10183/116452.
Council of Science Editors:
Caldas EM. Desenvolvimento de sílicas organofuncionalizadas para aplicação como sensores eletroquímicos. [Doctoral Dissertation]. Brazil; 2014. Available from: http://hdl.handle.net/10183/116452
13.
Bernardes, Arthur Alaím.
Encapsulamento de metalocenos em óxidos binários tipo SiO2-CrO3, SiO2-MoO3 e SiO2-WO3 através do método sol-gel não-hidrolítico : sistemas modificados com grupos organosilanos.
Degree: 2014, Brazil
URL: http://hdl.handle.net/10183/117613
► Este trabalho relata a síntese e caracterização de materiais à base de sílica (SiO2- CrO3, SiO2-MoO3, SiO2-WO3), com e sem metalocenos encapsulados, usando o processo…
(more)
▼ Este trabalho relata a síntese e caracterização de materiais à base de sílica (SiO2- CrO3, SiO2-MoO3, SiO2-WO3), com e sem metalocenos encapsulados, usando o processo de sol-gel não-hidrolítico. Os catalisadores foram avaliados na polimerização de etileno e os polímeros formados foram analisados por calorimetria diferencial de varredura (DSC) e cromatografia de permeação em gel (GPC). Investigou-se o efeito da presença de grupos ácidos e/ou grupos orgânicos no catalisador com a atividade catalítica e o efeito dos catalisadores nas reações de polimerização e no polímero gerado. Utilizando o processo sol-gel não-hidrolítico foi possível preparar catalisadores de polimerização de olefinas com características distintas, os quais permitem controlar as propriedades dos polímeros tanto pela alteração da acidez do suporte, quanto pela adição de grupamentos orgânicos na estrutura do mesmo. Tanto a presença de sítios ácidos no suporte (dotados de átomos de
Cr, Mo, W), quanto à presença de grupos organo-alcoxisilanos (MTMS, OTES e VTMS) afetam a atividade, pois regulam a quantidade de metaloceno retido ou liberado para o meio reacional. Algumas características dos materiais são bastante dependentes do tipo de metal incorporado à sílica e do tipo de organosilano, tais como: teor de metaloceno encapsulado, área específica e estrutura de rede. Os materiais sintetizados foram caracterizados através de uma série de técnicas analíticas, tais como: Porosimetria de N2, SAXS, MEV, EDX, FTIR, DRS-UV-Vis, Raman, XPS, EXAFS, DPV. O ambiente interno dos poros do suporte apresenta influência sobre a estrutura molecular do metaloceno encapsulado. A maior atividade desses catalisadores está relacionada a uma melhor interação entre o suporte e o sítio ativo do metaloceno. A interação entre o suporte e o metaloceno imobilizado reduz a densidade eletrônica em torno do Zr permitindo a ativação com concentrações mais baixas de co-catalisador. A densidade
eletrônica do Zr nos sistemas encapsulados pode ser ajustada tendo como base o tipo de metal (Cr, Mo, W) e o tipo de alcoxisilano incorporado à rede de sílica. De acordo com medidas de XPS, foram observadas energias de ligação do Zr mais altas quando comparadas ao metaloceno não encapsulado. Além disso, a atividade catalítica mostrou uma relação direta com o tamanho e forma dos fractais. Os catalisadores sintetizados produziram polímeros com massa molar média ponderal (Mw) superior àquela obtida com catalisador homogêneo.
This work describes the synthesis and characterization of materials (SiO2-CrO3, SiO2-MoO3, SiO2-WO3) with and without entrapped metallocenes using the nonhydrolytic sol-gel process. The catalysts were evaluated in ethylene polymerization and the resulting polymers formed were analyzed by differential scanning calorimetry (DSC) and gel permeation chromatography (GPC). The effect of the presence of acidic groups and/or organic groups in the catalyst with catalytic
activity and the effect of the catalysts in polymerization reactions and in the resulting polymer were investigated.…
Advisors/Committee Members: Santos, Joao Henrique Zimnoch dos.
Subjects/Keywords: Sílica; Polimerização; Sol-gel; Catalisadores
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Bernardes, A. A. (2014). Encapsulamento de metalocenos em óxidos binários tipo SiO2-CrO3, SiO2-MoO3 e SiO2-WO3 através do método sol-gel não-hidrolítico : sistemas modificados com grupos organosilanos. (Doctoral Dissertation). Brazil. Retrieved from http://hdl.handle.net/10183/117613
Chicago Manual of Style (16th Edition):
Bernardes, Arthur Alaím. “Encapsulamento de metalocenos em óxidos binários tipo SiO2-CrO3, SiO2-MoO3 e SiO2-WO3 através do método sol-gel não-hidrolítico : sistemas modificados com grupos organosilanos.” 2014. Doctoral Dissertation, Brazil. Accessed April 18, 2021.
http://hdl.handle.net/10183/117613.
MLA Handbook (7th Edition):
Bernardes, Arthur Alaím. “Encapsulamento de metalocenos em óxidos binários tipo SiO2-CrO3, SiO2-MoO3 e SiO2-WO3 através do método sol-gel não-hidrolítico : sistemas modificados com grupos organosilanos.” 2014. Web. 18 Apr 2021.
Vancouver:
Bernardes AA. Encapsulamento de metalocenos em óxidos binários tipo SiO2-CrO3, SiO2-MoO3 e SiO2-WO3 através do método sol-gel não-hidrolítico : sistemas modificados com grupos organosilanos. [Internet] [Doctoral dissertation]. Brazil; 2014. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/10183/117613.
Council of Science Editors:
Bernardes AA. Encapsulamento de metalocenos em óxidos binários tipo SiO2-CrO3, SiO2-MoO3 e SiO2-WO3 através do método sol-gel não-hidrolítico : sistemas modificados com grupos organosilanos. [Doctoral Dissertation]. Brazil; 2014. Available from: http://hdl.handle.net/10183/117613
14.
Ricardi, Natália Carminatti.
Desenvolvimento de suportes porosos de sílica e suportes híbridos de sílica/quitosana para aplicação em catálise enzimática.
Degree: 2016, Brazil
URL: http://hdl.handle.net/10183/148459
► Em biocatálise, tem crescido o uso de enzimas imobilizadas em função das diferentes vantagens observadas pelo uso desta técnica, quando comparada ao o uso de…
(more)
▼ Em biocatálise, tem crescido o uso de enzimas imobilizadas em função das diferentes vantagens observadas pelo uso desta técnica, quando comparada ao o uso de enzimas livres. O bom desempenho de enzimas imobilizadas está diretamente relacionado ao tipo de suporte usado no processo de imobilização. Neste sentido, é de fundamental importância a busca por novos suportes que aliem qualidades mecânicas, biocompatibilidade e que, ao mesmo tempo, consigam melhorar as características da enzima a ser imobilizada. No presente trabalho foram desenvolvidos materiais híbridos a base de sílica, contendo diferentes proporções de quitosana, 10 e 20%, e um material a base de sílica que foi organofuncionalizado com APTMS. A enzima escolhida como modelo foi a β-galactosidase devido a sua aplicação na indústria de alimentos. A fim de proceder à imobilização covalente da enzima, foi realizada a ativação dos suportes com glutaraldeído. Os três materiais, com e sem enzima
imobilizada, foram caracterizados por espectroscopia na região do infravermelho, análise elementar C, H, N e termogravimétrica, comprovando a incorporação da quitosana. Isotermas de adsorção e dessorção de N2 mostraram que os materiais são mesoporosos e que a enzima não está bloqueando os poros. Por outro lado, a microscopia eletrônica de varredura indicou que a quitosana está dispersa em regiões micrométricas na sílica. O desempenho dos materiais imobilizados como biocatalisadores foi testado para a reação de hidrólise da lactose. Quanto aos parâmetros de imobilização, foi observado um maior rendimento de imobilização na matriz de sílica. No entanto, a enzima imobilizada nas matrizes híbridas com 10 e 20% de quitosana apresentou maiores valores de eficiência, respectivamente 62 e 47%, enquanto que para a sílica pura a eficiência foi de 37%. Tanto enzima livre quanto a imobilizada nos diferentes suportes apresentaram uma tendência semelhante à perda de atividade relativa quando
submetidas a tratamento térmico. Além disso, a imobilização da enzima não apresentou melhorias na amplitude dos valores de atividade relativa em diferentes pH(s). A estabilidade operacional da enzima imobilizada foi avaliada pela hidrólise da lactose utilizando um reator de leito fixo, no qual, tanto o imobilizado enzimático em suporte de sílica pura quanto o do material híbrido, permaneceram com aproximadamente 100% de atividade por um período de uso contínuo de 200 horas. Sendo assim, o suporte híbrido proposto proporcionou a manutenção da atividade catalítica da enzima imobilizada, tornando-se uma alternativa viável e interessante para a aplicação na indústria de alimentos, uma vez que a presença de quitosana agrega outras características além da estabilidade mecânica própria da sílica.
In biocatalysis, the use of immobilized enzymes has grown, in terms of different advantages observed by the use of this technique as compared to the use of free enzymes. The good performance of
immobilized enzymes is directly related to the type of support used in the immobilization process. In this sense, the…
Advisors/Committee Members: Costa, Tania Maria Haas, Hertz, Plinho Francisco.
Subjects/Keywords: Sílica; Quitosana; Sol-gel
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
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APA (6th Edition):
Ricardi, N. C. (2016). Desenvolvimento de suportes porosos de sílica e suportes híbridos de sílica/quitosana para aplicação em catálise enzimática. (Masters Thesis). Brazil. Retrieved from http://hdl.handle.net/10183/148459
Chicago Manual of Style (16th Edition):
Ricardi, Natália Carminatti. “Desenvolvimento de suportes porosos de sílica e suportes híbridos de sílica/quitosana para aplicação em catálise enzimática.” 2016. Masters Thesis, Brazil. Accessed April 18, 2021.
http://hdl.handle.net/10183/148459.
MLA Handbook (7th Edition):
Ricardi, Natália Carminatti. “Desenvolvimento de suportes porosos de sílica e suportes híbridos de sílica/quitosana para aplicação em catálise enzimática.” 2016. Web. 18 Apr 2021.
Vancouver:
Ricardi NC. Desenvolvimento de suportes porosos de sílica e suportes híbridos de sílica/quitosana para aplicação em catálise enzimática. [Internet] [Masters thesis]. Brazil; 2016. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/10183/148459.
Council of Science Editors:
Ricardi NC. Desenvolvimento de suportes porosos de sílica e suportes híbridos de sílica/quitosana para aplicação em catálise enzimática. [Masters Thesis]. Brazil; 2016. Available from: http://hdl.handle.net/10183/148459
15.
Ullmann, Marcius Andrei.
Síntese sol-gel não-hidrolítica na heterogeneização de metalocenos em sílicas híbridas para produção de polietilenos.
Degree: 2019, Brazil
URL: http://hdl.handle.net/10183/201174
► Zirconocenos (Cp2ZrCl2) foram imobilizados via encapsulamento, através da síntese da sílica pelo método sol-gel não-hidrolítico (NH), com o intuito de produzir sistemas ativos com tendência…
(more)
▼ Zirconocenos (Cp2ZrCl2) foram imobilizados via encapsulamento, através da síntese da sílica pelo método sol-gel não-hidrolítico (NH), com o intuito de produzir sistemas ativos com tendência à polidispersão de massas do polímero. As rotas de imobilização direta do metaloceno sobre sílica comercial, através da técnica de grafting (GS) e sol-gel não-hidrolítico (NH) foram comparadas. Os sistemas catalíticos heterogêneos sintetizados foram avaliados na polimerização de etileno, tendo metilaluminoxano (MAO) como cocatalisador. Sistemas mistos e híbridos contendo W foram os mais produtivos, indicando que sítios ácidos de Lewis na superfície da sílica, gerados pelo ambiente de rede modificado por metais (Cr, Mo ou W), potencializam o sítio ativo. A rota de imobilização, o tamanho da cadeia alquílica do silano empregado e a existência ou não de uma segunda camada afeta a atividade dos polietilenos produzidos. A microestrutura dos sistemas, revelada por
SAXS, mostra que partículas formadas por duas camadas e espaçadas por alquilsilanos contendo 8 ou 18 carbonos possuem maiores partículas primárias que favorecem a atividade. Ante o contaminante (acetona), os sistemas modificados com ácidos de Lewis toleraram até 0,3 g·g-1. Os sistemas arquitetados em duas camadas de sílica apresentaram atividade relativa superior aos sistemas mistos encapsulados em uma camada de sílica quando da adição da mesma quantidade do contaminante. As medidas de ATR mostraram que a acetona possui afinidade pela superfície dos sistemas preparados pelo método NH que apresentavam W-O-Si. O resultado é indicativo de que ácidos de Lewis formados na superfície do sólido agem como componente de sacrifício frente à cetona, mantendo o sítio ativo na polimerização.
Zirconocenes (Cp2ZrCl2) were immobilized via encapsulation through the synthesis of silica by the non-hydrolytic sol-gel (NH) method, with the aim of producing active systems with a polydispersity polymer
masses. The direct immobilization routes of metallocene on commercial silica by grafting technique (GS) and non-hydrolytic sol-gel (NH) were compared. The heterogeneous systems were evaluated in the polymerization of ethylene, having methylaluminoxane (MAO) as cocatalyst. Mixed and hybrid systems containing W were the most productive, indicating that active site were potentiate by Lewis acid sites generated on the silica surface due to metal environment network (Cr, Mo or W). The immobilization route, the size of the employed alkylsilane chain and a dual-shell system affects the activity of the polyethylenes produced. The microstructure of the systems, displayed by SAXS, shows that particles formed by two layers and spaced by alkylsilanes containing 8 or 18 carbons have larger primary particles that get higher activity. Systems modified with Lewis acids tolerated up to 0.3 g·g-1 of the contaminant (acetone) concentration. The systems architected in two silica layers presented
superior higher relative activity than the mixed systems encapsulated in a one silica layer when adding the same amount of…
Advisors/Committee Members: Santos, Joao Henrique Zimnoch dos.
Subjects/Keywords: Zirconocenos; Sol-gel; Polímeros; Sílica
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Ullmann, M. A. (2019). Síntese sol-gel não-hidrolítica na heterogeneização de metalocenos em sílicas híbridas para produção de polietilenos. (Doctoral Dissertation). Brazil. Retrieved from http://hdl.handle.net/10183/201174
Chicago Manual of Style (16th Edition):
Ullmann, Marcius Andrei. “Síntese sol-gel não-hidrolítica na heterogeneização de metalocenos em sílicas híbridas para produção de polietilenos.” 2019. Doctoral Dissertation, Brazil. Accessed April 18, 2021.
http://hdl.handle.net/10183/201174.
MLA Handbook (7th Edition):
Ullmann, Marcius Andrei. “Síntese sol-gel não-hidrolítica na heterogeneização de metalocenos em sílicas híbridas para produção de polietilenos.” 2019. Web. 18 Apr 2021.
Vancouver:
Ullmann MA. Síntese sol-gel não-hidrolítica na heterogeneização de metalocenos em sílicas híbridas para produção de polietilenos. [Internet] [Doctoral dissertation]. Brazil; 2019. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/10183/201174.
Council of Science Editors:
Ullmann MA. Síntese sol-gel não-hidrolítica na heterogeneização de metalocenos em sílicas híbridas para produção de polietilenos. [Doctoral Dissertation]. Brazil; 2019. Available from: http://hdl.handle.net/10183/201174
16.
Grando, Sílvia Regina.
Uso da metodologia sol-gel na preparação de materiais amorfos e nanoestruturados à base de sílica contendo grupos orgânicos com propriedades específicas.
Degree: 2014, Brazil
URL: http://hdl.handle.net/10183/97875
► Nesse trabalho foram desenvolvidos novos materiais à base de sílica, amorfos e nanoestruturados, pelo método sol-gel de síntese e a adição de precursores com grupos…
(more)
▼ Nesse trabalho foram desenvolvidos novos materiais à base de sílica, amorfos e nanoestruturados, pelo método
sol-
gel de síntese e a adição de precursores com grupos funcionais específicos. Inicialmente foi investigado o comportamento fotofísico de benzazolas dispersas em xerogéis híbridos com diferentes hidrofobicidades, preparados com a adição de diferentes porcentagens molares do precursor dimetildimetoxisilano (DDMS). Nos espectros normalizados de emissão de fluorescência do corante 2-(5’-amino-2’-hidroxifenil) benzimidazol (5-AHBI) disperso nos xerogéis híbridos foram observadas duas bandas, uma delas atribuída a emissão normal (N*) e a outra atribuída a emissão pelo mecanismo de transferência protônica intramolecular no estado excitado - ESIPT (E*), com deslocamento de Stokes próximo a 150 nm. Nos híbridos contendo o corante 2-(5’-amino-2’-hidroxifenil) benzotiazol (5-AHBT), observou-se uma banda bastante alargada em que a emissão de
fluorescência mostrou-se dependente da polaridade da matriz, com a emissão máxima variando de 496 para 533 nm com o aumento da porcentagem de DDMS nas sínteses. Sílicas mesoporosas ordenadas do tipo MCM-41 e SBA-15 foram sintetizadas e os resultados de difração de raios X (XRD) e das isotermas de adsorção-dessorção de N2 desses materiais mostraram organização hexagonal de poros, elevadas áreas superficiais específicas, volume de poros de 0,90 cm3 g-1 e distribuição uniforme de mesoporos. Adicionalmente, o uso de autoclave na síntese da sílica MCM-41 parece ter contribuído para uma melhor organização estrutural. Nanopartículas de paládio (NPPd) estabilizadas em solução aquosa pelo silsesquioxano iônico DABCOSIL foram então suportadas nas sílicas mesoporosas ordenadas. As imagens de microscopia eletrônica de transmissão (TEM) mostraram NPPd com tamanho médio de 4 nm nos canais da matriz de sílica SBA-15, que se mostrou mais eficiente como suporte das NPPd em relação à sílica MCM-41. A
sílica SBA-15 contendo as NPPd foi utilizada como catalisador heterogêneo em reações de acoplamento Suzuki, com taxas de conversão na ordem de 90 % para o 4-bromotolueno após quatro ciclos de reação. A influência da quantidade e do tipo de precursor contendo grupos orgânicos em ponte na formação de Organossílicas Mesoporosas Ordenadas (PMOs) também foi investigada. Foram preparadas PMOs usando-se o precursor 1,4-bis(trietoxisililpropilureido) benzeno (BDU) em diferentes porcentagens molares e brometo de hexadeciltrimetilamônio (CTAB) como agente direcionador de estrutura, em meio básico. O aumento da quantidade do grupo orgânico do precursor nos híbridos foi confirmada por análise elementar (CHN), análise termogravimétrica (TGA), ressonância magnética nuclear no estado sólido (29Si-NMR) e espectroscopia de absorção no infravermelho (FTIR). As propriedades estruturais e texturais dos híbridos foram analisadas por difração de raios X (XRD) e isotermas de adsorção-dessorção de N2
respectivamente, observando-se que o aumento na porcentagem de BDU provocou diminuição na organização estrutural e colapso dos…
Advisors/Committee Members: Costa, Tania Maria Haas, Campo, Leandra Franciscato.
Subjects/Keywords: Xerogel híbrido; Sol-gel; Sílica
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Grando, S. R. (2014). Uso da metodologia sol-gel na preparação de materiais amorfos e nanoestruturados à base de sílica contendo grupos orgânicos com propriedades específicas. (Doctoral Dissertation). Brazil. Retrieved from http://hdl.handle.net/10183/97875
Chicago Manual of Style (16th Edition):
Grando, Sílvia Regina. “Uso da metodologia sol-gel na preparação de materiais amorfos e nanoestruturados à base de sílica contendo grupos orgânicos com propriedades específicas.” 2014. Doctoral Dissertation, Brazil. Accessed April 18, 2021.
http://hdl.handle.net/10183/97875.
MLA Handbook (7th Edition):
Grando, Sílvia Regina. “Uso da metodologia sol-gel na preparação de materiais amorfos e nanoestruturados à base de sílica contendo grupos orgânicos com propriedades específicas.” 2014. Web. 18 Apr 2021.
Vancouver:
Grando SR. Uso da metodologia sol-gel na preparação de materiais amorfos e nanoestruturados à base de sílica contendo grupos orgânicos com propriedades específicas. [Internet] [Doctoral dissertation]. Brazil; 2014. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/10183/97875.
Council of Science Editors:
Grando SR. Uso da metodologia sol-gel na preparação de materiais amorfos e nanoestruturados à base de sílica contendo grupos orgânicos com propriedades específicas. [Doctoral Dissertation]. Brazil; 2014. Available from: http://hdl.handle.net/10183/97875
17.
Donato, Katarzyna Joanna Zawada.
Líquidos iônicos como aditivos em nanocompósitos de matrizes termoplásticas.
Degree: 2016, Brazil
URL: http://hdl.handle.net/10183/157894
► Neste trabalho foram investigados sistemas de sílica sintetizados via processo sol-gel na presença de líquidos iônicos imidazólicos (LI) e sua aplicação como cargas em matrizes…
(more)
▼ Neste trabalho foram investigados sistemas de sílica sintetizados via processo sol-gel na presença de líquidos iônicos imidazólicos (LI) e sua aplicação como cargas em matrizes termoplásticas de álcool polivinílico altamente amorfo (PVOH) e polietileno de alta densidade (PEAD). Os híbridos de sílica-LI foram preparados através de um processo sol-gel na presença de LI com diferentes cátions e ânions, utilizando tetraetoxisilano (TEOS) como precursor. Em uma primeira etapa, as propriedades dos géis e dos xerogéis modificados formados foram estudados em detalhes. Para avaliar as morfologias dos xerogéis, um conjunto complementar de microscopias de transmissão (TEM), de varredura (SEM) e de força atômica (AFM) foi utilizado. Difração de raios X (XRD), espalhamento de raios X em baixo e amplo ângulo (SWAXS), isoterma de adsorção-dessorção de nitrogênio (BET e BJH) e análise termogravimétrica (TGA) foram utilizados para investigar os parâmetros
estruturais e térmicos. Na segunda parte da pesquisa, os híbridos sílica-LI em diferentes condições: maturados e secos (xerogel), apenas hidrolisados (sol) ou precipitados; foram processados com PEAD no estado fundido em câmera de misturas. Já os nanocompósitos de PVOH foram preparados via processo casting, onde ocorre a evaporação de solvente da solução aquosa do polímero simultaneamente com a reação de condensação in situ dos híbridos sílica-LI a partir da sol pré-hidrolizada Nanocompósitos com adição de 3% (em massa) de nanocarga em matriz polimérica foram obtidos utilizando menos que 1% de LI nos processos. As propriedades térmicas dos sistemas foram investigadas por análise exploratória diferencial (DSC) e por TGA. As estruturas e morfologias foram analisadas por SWAXS, TEM e SEM. As propriedades mecânicas foram avaliadas por análises dinâmico-mecânicas (DMA) e testes de tração, enquanto suas propriedades de barreira foram determinadas por testes de permeabilidade ao vapor
d’água. Nestes sistemas os LI controlam parâmetros estruturais e interfaciais influenciando tamanho, forma, distribuição e orientação das cargas, além de atuar como compatibilizantes entre carga e matriz polimérica. Com isso, os LI fornecem aos nanocompósitos finais melhorias nas propriedades físico-químicas e termomecânicas, como rigidez, elasticidade, propriedades de barreira e resistência térmica.
In this study, sol-gel silica systems synthesized with imidazolium ionic liquids (IL) and their use as fillers in high amorphous polyvinyl alcohol (PVOH) and high density polyethylene (HDPE) were investigated. The silica hybrids were prepared using tetraethyl orthosilicate (TEOS) as a silica precursor in a sol-gel process in the presence of IL, with different cations and anions. In the first step, the properties of the gels and xerogels were studied in details. In order to evaluate the xerogels morphologies, the complementary set of transmission (TEM), scanning (SEM) and atomic force
(AFM) microscopies was used. X-ray diffraction (XRD), small- and wide-angle X-ray scattering (SWAXS), nitrogen…
Advisors/Committee Members: Mauler, Raquel Santos, Schrekker, Henri Stephan.
Subjects/Keywords: Nanocompósitos; Líquidos iônicos; Sol-gel
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Donato, K. J. Z. (2016). Líquidos iônicos como aditivos em nanocompósitos de matrizes termoplásticas. (Doctoral Dissertation). Brazil. Retrieved from http://hdl.handle.net/10183/157894
Chicago Manual of Style (16th Edition):
Donato, Katarzyna Joanna Zawada. “Líquidos iônicos como aditivos em nanocompósitos de matrizes termoplásticas.” 2016. Doctoral Dissertation, Brazil. Accessed April 18, 2021.
http://hdl.handle.net/10183/157894.
MLA Handbook (7th Edition):
Donato, Katarzyna Joanna Zawada. “Líquidos iônicos como aditivos em nanocompósitos de matrizes termoplásticas.” 2016. Web. 18 Apr 2021.
Vancouver:
Donato KJZ. Líquidos iônicos como aditivos em nanocompósitos de matrizes termoplásticas. [Internet] [Doctoral dissertation]. Brazil; 2016. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/10183/157894.
Council of Science Editors:
Donato KJZ. Líquidos iônicos como aditivos em nanocompósitos de matrizes termoplásticas. [Doctoral Dissertation]. Brazil; 2016. Available from: http://hdl.handle.net/10183/157894
18.
Capeletti, Larissa Brentano.
Sílicas híbridas : potencialidades de ajuste da atividade de moléculas encapsuladas por meio da natureza do organosilano.
Degree: 2014, Brazil
URL: http://hdl.handle.net/10183/109685
► Diferentes sílicas híbridas foram utilizadas na investigação do ajuste da atividade de materiais sintetizados por encapsulamento de moléculas pelo método solgel. Quatro diferentes aplicações obtidas…
(more)
▼ Diferentes sílicas híbridas foram utilizadas na investigação do ajuste da atividade de materiais sintetizados por encapsulamento de moléculas pelo método solgel. Quatro diferentes aplicações obtidas por diferentes rotas sol-gel foram exploradas: sensores colorimétricos (rota hidrolítica ácida), antimicrobianos (rota hidrolítica básica), catalisadores (rota não hidrolítica) e filmes para crescimento celular (rota ácida). Onze organosilanos com diferentes grupos orgânicos, diferentes efeitos estéricos e indutivos foram empregados: metil, octil, octadecil, vinil, fenil, aminopropil, mercaptopropil, isocianatopropil, cloropropil, iodopropil e glicidoxipropil. As características estruturais, texturais, morfológicas e atividade foram avaliadas e os resultados foram correlacionados com as diferentes rotas e organosilanos empregados. A performance dos sensores colorimétricos foi avaliada em função do tempo de resposta de detecção do gás amônia e mudança de
cor por colorimetria. Os antimicrobianos foram avaliados na presença das bactérias gram negativa Escherichia coli e gram positiva Staphylococcus aureus. Os catalisadores foram avaliados na polimerização de etileno e os polímeros formados foram analisados por calorimetria diferencial de varredura (DSC) e cromatografia de permeação em gel (GPC). Os filmes híbridos foram testados no crescimento e regeneração de células neuronais utilizando microscopia de fluorescência. Esse estudo mostrou que juntamente com a rota escolhida para preparo, os organosilanos afetam diversas propriedades dos materiais. Algumas características são bastante dependentes do organosilano como o teor encapsulado, área específica e estrutura de rede. Outras características como microestrutura e morfologia foram mais influenciadas pela rota escolhida. Entretanto, analisando o conjunto de dados gerado do ponto de vista da performance de atividade dos diferentes materiais notou-se também a influência dos
organosilanos. Seu uso implicou em mudanças na estrutura e textura das matrizes, o que influência na compatibilidade do material com o meio de aplicação e também no controle do acesso ao composto imobilizado ou de sua liberação. Também pode haver uma interação direta com o organosilano influenciando no controle do balanço entre retenção/liberação dos compostos imobilizados ou mesmo alterando sua identidade. Essa combinação de efeitos demonstrou o potencial de ajuste da atividade de moléculas alvo empregando organosilanos.
Different hybrid silicas were employed in the activity tuning investigation of different materials synthesized by sol-gel process encapsulation. Four different applications prepared by different sol-gel routes were explored: Colorimetric sensors (hydrolytic acid route), antimicrobial materials (hydrolytic basic route), catalysts (nonhydrolytic route) and films for cell growth (hydrolytic acid route with a second catalyst). Eleven organosilanes with organic groups
bearing different steric and inductive effects were employed: methyl, octyl, octadecyl, vinyl, phenyl, aminopropyl,…
Advisors/Committee Members: Santos, Joao Henrique Zimnoch dos, Cardoso, Mateus Borba.
Subjects/Keywords: Sílica híbrida; Polimerização; Sol-gel
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Capeletti, L. B. (2014). Sílicas híbridas : potencialidades de ajuste da atividade de moléculas encapsuladas por meio da natureza do organosilano. (Doctoral Dissertation). Brazil. Retrieved from http://hdl.handle.net/10183/109685
Chicago Manual of Style (16th Edition):
Capeletti, Larissa Brentano. “Sílicas híbridas : potencialidades de ajuste da atividade de moléculas encapsuladas por meio da natureza do organosilano.” 2014. Doctoral Dissertation, Brazil. Accessed April 18, 2021.
http://hdl.handle.net/10183/109685.
MLA Handbook (7th Edition):
Capeletti, Larissa Brentano. “Sílicas híbridas : potencialidades de ajuste da atividade de moléculas encapsuladas por meio da natureza do organosilano.” 2014. Web. 18 Apr 2021.
Vancouver:
Capeletti LB. Sílicas híbridas : potencialidades de ajuste da atividade de moléculas encapsuladas por meio da natureza do organosilano. [Internet] [Doctoral dissertation]. Brazil; 2014. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/10183/109685.
Council of Science Editors:
Capeletti LB. Sílicas híbridas : potencialidades de ajuste da atividade de moléculas encapsuladas por meio da natureza do organosilano. [Doctoral Dissertation]. Brazil; 2014. Available from: http://hdl.handle.net/10183/109685
19.
Santos, Cristiane dos.
Encapsulamento de taninos de acácia mearnsii por métodos sol-gel.
Degree: 2014, Brazil
URL: http://hdl.handle.net/10183/194181
► Neste trabalho, taninos de Acacia mearnsii foram encapsulados por quatro diferentes rotas de síntese sol-gel. Os materiais híbridos obtidos foram caracterizados por suas propriedades estruturais,…
(more)
▼ Neste trabalho, taninos de Acacia mearnsii foram encapsulados por quatro diferentes rotas de síntese sol-gel. Os materiais híbridos obtidos foram caracterizados por suas propriedades estruturais, texturais e morfológicas englobando um conjunto de técnicas. As propriedades funcionais foram testadas por ensaios de curtimento de couro piquelado, recurtimento de couro wet blue e como antimicrobiano frente a diferentes microorganismos. Os conjuntos de dados obtidos mostraram que a rota de encapsulamento afeta nitidamente as características dos materiais híbridos gerados. Os materiais híbridos que apresentaram melhor desempenho funcional foram os obtidos por rota silicato que produziram materiais mesoporosos com baixa área específica, em torno de 0,96 m2 .g-1 , e tamanho de partículas menores que 1 nm. Estas características promoveram nos ensaios de atividade a liberação gradual dos taninos em meio aquoso e melhor interação com as proteínas do couro.
Além disso, o processo demonstrou a preservação dos taninos após a síntese, maior teor de taninos encapsulados e melhor rendimento reacional. Nos ensaios funcionais, os couros obtidos com estes materiais híbridos apresentaram melhores resultados de solidez à luz após exposição à luz ultravioleta em relação aos taninos não encapsulados e, melhor atividade antimicrobiana em comparação aos demais materiais sintetizados.
In this work, tannins from Acacia mearnsii were encapsulated by four different sol-gel routes. The hybrid materials were analyzed by a set of techniques aiming at their structural, textural and morphological characterization. The performance of the encapsuled materials evaluation in leather tanning, in wet blue retanning and as antimicrobial against different microorganisms. The data sets showed that the encapsulation route significantly affects the characteristics of the resulting hybrid materials. Better functional performances were obtained by silicate route that
produced mesoporous materials with low surface area (0,96 m2 .g-1 ) and small particle size (< 1 nm). These characteristics have promoted the gradual release of tannins in an aqueous medium and improved their interaction with proteins leather. Furthermore, the process demonstrated the preservation of tannins after synthesis and afforded encapsulated content. In functional assays, the skins obtained with these hybrid materials showed better results of light fastness after exposure to UV light if compared to unencapsulated free tannins and better antimicrobial activity compared to other synthesized materials.
Advisors/Committee Members: Santos, Joao Henrique Zimnoch dos.
Subjects/Keywords: Acácia; Materiais híbridos; Sol-gel
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Santos, C. d. (2014). Encapsulamento de taninos de acácia mearnsii por métodos sol-gel. (Masters Thesis). Brazil. Retrieved from http://hdl.handle.net/10183/194181
Chicago Manual of Style (16th Edition):
Santos, Cristiane dos. “Encapsulamento de taninos de acácia mearnsii por métodos sol-gel.” 2014. Masters Thesis, Brazil. Accessed April 18, 2021.
http://hdl.handle.net/10183/194181.
MLA Handbook (7th Edition):
Santos, Cristiane dos. “Encapsulamento de taninos de acácia mearnsii por métodos sol-gel.” 2014. Web. 18 Apr 2021.
Vancouver:
Santos Cd. Encapsulamento de taninos de acácia mearnsii por métodos sol-gel. [Internet] [Masters thesis]. Brazil; 2014. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/10183/194181.
Council of Science Editors:
Santos Cd. Encapsulamento de taninos de acácia mearnsii por métodos sol-gel. [Masters Thesis]. Brazil; 2014. Available from: http://hdl.handle.net/10183/194181
20.
João Paulo da Silva Scaramal.
Incorporação de porfirinas em matrizes Sol-Gel: Preparação e caracterização espectroscópica.
Degree: 2011, UNICENTRO – Universidade Estadual do Centro Oeste
URL: http://tede.unicentro.br/tde_busca/arquivo.php?codArquivo=89
► Nos últimos anos as porfirinas e seus derivados vêm se destacando nos estudos científicos devido as suas propriedades catalíticas e luminescentes. Uma grande variedade de…
(more)
▼ Nos últimos anos as porfirinas e seus derivados vêm se destacando nos estudos científicos devido as suas propriedades catalíticas e luminescentes. Uma grande variedade de agentes fotossensibilizadores foi produzida e eles têm sido extensivamente estudados devido as suas propriedades fotoquímicas e fotofísicas. A imobilização de porfirinas em matrizes de sol-gel é de grande interesse devido as suas aplicações em sensores químicos e bioquímicos, aumentando sua fotoestabilidade, e em catalisadores. A obtenção de matrizes inorgânicas através do processo sol-gel é um caminho bastante promissor para se chegar a suportes de grande pureza e homogeneidade, e temperatura de processamentos muito inferiores quando comparados aqueles formados pelos métodos tradicionais de obtenção de revestimentos. Desta forma, estudamos neste trabalho a incorporação das porfirinas, Tetrakis (n-metil-4- piridil) porfirina (TMPyP) na base livre e complexada com Fe3+, Fe (III) Tetrakis (n-metil-4- piridil) porfirina (FeTMPYP) em matrizes de Sol-Gel. Foi sintetizado e comparado dois métodos de preparação dos géis, método Pechini, o método dos precursores poliméricos, e o método Sol-Gel utilizando TEOS (Tetraetilortosilicato), método que consiste na hidrólise do tetraetilortosilicato; na forma de filmes finos. A deposição dos géis foi feita em lamínulas para microscopia através das técnicas Dip e Spin Coanting e então comparadas. Os filmes foram caracterizados através das medidas de: Microscopia Eletrônica de Varredura (MEV), Espectroscopia de Energia Dispersiva (EDS) e Microscopia de Força Atômica (AFM). O filme obtido pelo método Pechini mostrou-se mais qualificado para a incorporação das porfirinas, pois apresentou estruturas mais homogêneas. As porfirinas foram incorporadas aos filmes através da técnica Dip-Coating e Spin-Coating. Os filmes foram novamente caracterizados para confirmar a presença das porfirinas nos filmes através das técnicas Espectroscopia no Infra-Vermelho e Espectroscopia no Ultravioleta Visível. Os resultados mostraram que as porfirinas foram incorporadas aos filmes feitos pelo método Pechini através da técnica Dip-Coating.
In recent years, porphyrins and their derivatives have been highlighted in scientific studies due to their catalytic and luminescent properties. A wide variety of photosensitizing agents were produced and they have been extensively studied because of their photophysical and photochemical properties. Immobilization of porphyrins in sol-gel matrices is of great interest because their applications in chemical and biochemical sensors, increasing their photostability, and catalysts. The acquisition of inorganic matrices through the sol-gel process is a promising way to reach supporters of high purity and homogeneity, and much lower processing temperature compared those formed by traditional methods of obtaining coatings. Thus, we studied in this work the incorporation of porphyrins, Tetrakis (N-methyl-4-pyridyl) porphyrin (TMPyP) in the free base and complexed with Fe 3 +, Fe (III) Tetrakis…
Advisors/Committee Members: Tania Toyomi Tominaga.
Subjects/Keywords: Porfirinas; Sol-Gel; Filmes finos; Porphyrins; Sol-Gel; Thin films; QUIMICA
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Scaramal, J. P. d. S. (2011). Incorporação de porfirinas em matrizes Sol-Gel: Preparação e caracterização espectroscópica. (Thesis). UNICENTRO – Universidade Estadual do Centro Oeste. Retrieved from http://tede.unicentro.br/tde_busca/arquivo.php?codArquivo=89
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Scaramal, João Paulo da Silva. “Incorporação de porfirinas em matrizes Sol-Gel: Preparação e caracterização espectroscópica.” 2011. Thesis, UNICENTRO – Universidade Estadual do Centro Oeste. Accessed April 18, 2021.
http://tede.unicentro.br/tde_busca/arquivo.php?codArquivo=89.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Scaramal, João Paulo da Silva. “Incorporação de porfirinas em matrizes Sol-Gel: Preparação e caracterização espectroscópica.” 2011. Web. 18 Apr 2021.
Vancouver:
Scaramal JPdS. Incorporação de porfirinas em matrizes Sol-Gel: Preparação e caracterização espectroscópica. [Internet] [Thesis]. UNICENTRO – Universidade Estadual do Centro Oeste; 2011. [cited 2021 Apr 18].
Available from: http://tede.unicentro.br/tde_busca/arquivo.php?codArquivo=89.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Scaramal JPdS. Incorporação de porfirinas em matrizes Sol-Gel: Preparação e caracterização espectroscópica. [Thesis]. UNICENTRO – Universidade Estadual do Centro Oeste; 2011. Available from: http://tede.unicentro.br/tde_busca/arquivo.php?codArquivo=89
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
21.
Montheil, Titouan.
Conception d’hydrogels hybrides pour la préparation de géloses synthétiques : Design and synthesis of silylated hybrid hydrogels.
Degree: Docteur es, Chimie et physico-chimie des matériaux, 2020, Montpellier
URL: http://www.theses.fr/2020MONTS012
► Des hydrogels hybrides ont été développés comme alternative aux hydrogels d’agar utilisés en microbiologie. Notre stratégie repose sur la fonctionnalisation de polymères avec des groupements…
(more)
▼ Des hydrogels hybrides ont été développés comme alternative aux hydrogels d’agar utilisés en microbiologie. Notre stratégie repose sur la fonctionnalisation de polymères avec des groupements triéthoxysilanes, puis leurs mises en jeu dans le procédé sol-gel afin de fabriquer un hydrogel hybride organique-inorganique. Ce procédé est bio-orthogonal et biocompatible. Il se déroule en milieu aqueux, à pH physiologique et température ambiante. Dans une première partie, nous avons développé des hydrogels à base de PEG bisilylé. Nous avons montré que l’incorporation de PEG monosilylé permettait un relâchement du réseau de l’hydrogel. Dans une seconde partie, nous avons développé des hydrogels à base d’hydroxypropyl méthyl cellulose (HPMC). L’optimisation de la silylation de ce composé a été réalisée. L’étude de la composition de l’hydrogel (masse molaire de l’HPMC, concentration, taux de silylation) a été étudiée et a permis la préparation d’hydrogels aux propriétés similaires aux références commerciales d’agar. Nous avons ensuite étendu notre étude aux hydrogels hybrides à base d’autres polysaccharides. Le chitosan, la dextrine, la pectine et l’acide hyaluronique ont ainsi été silylés et des hydrogels hybrides ont été préparés à partir de ces précurseurs. Les hydrogels de dextrine silylée se sont révélés les plus prometteurs pour une application à la microbiologie. La composition a été optimisée et les tests microbiologiques ont validé ce composé comme une alternative à l’agar.Nous avons montré que les hydrogels synthétiques obtenus par le procédé sol-gel constituaient une alternative solide aux hydrogels d’agar. La maitrise des différents paramètres (ex : silylation, mise en forme, composition) permet d’adapter leurs propriétés.
Hybrid hydrogels have been developed as an alternative to agar hydrogels used in microbiology. Our strategy is based on the functionalization of polymers with triethoxysilane groups, and then their use in the sol-gel process to produce an organic-inorganic hybrid hydrogels. This process is bio-orthogonal and biocompatible. It takes place in aqueous medium, at physiological pH and ambient temperature. In a first part, we developed hydrogels based on bisilylated PEG. We have shown that the incorporation of monosilylated PEG allowed a loosening of the hydrogel network. In a second part, we developed hydrogels based on hydroxypropyl methyl cellulose (HPMC). Silylation of HPMC silylation has been optimised. The study of hydrogel composition (HPMC molecular weight, concentration, silylation rate) allowed the production of hydrogels with properties similar to the agar commercial references. We then extended our study to hybrid hydrogels made from others polysaccharides. Chitosan, dextrin, pectin and hyaluronic acid were thus silylated and hybrid hydrogels were prepared from these precursors. Silylated dextrin hydrogels proved to be highly suitable for microbiology applicationWe showed that synthetics hydrogels obtained by sol-gel process constituted a solid alternative to agar hydrogels. The control of…
Advisors/Committee Members: Subra, Gilles (thesis director), Mao, Bosi (thesis director).
Subjects/Keywords: Hydrogel; Procédé sol-gel; Polysaccharide; Hydrogel; Sol-Gel process; Polysaccharide
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Montheil, T. (2020). Conception d’hydrogels hybrides pour la préparation de géloses synthétiques : Design and synthesis of silylated hybrid hydrogels. (Doctoral Dissertation). Montpellier. Retrieved from http://www.theses.fr/2020MONTS012
Chicago Manual of Style (16th Edition):
Montheil, Titouan. “Conception d’hydrogels hybrides pour la préparation de géloses synthétiques : Design and synthesis of silylated hybrid hydrogels.” 2020. Doctoral Dissertation, Montpellier. Accessed April 18, 2021.
http://www.theses.fr/2020MONTS012.
MLA Handbook (7th Edition):
Montheil, Titouan. “Conception d’hydrogels hybrides pour la préparation de géloses synthétiques : Design and synthesis of silylated hybrid hydrogels.” 2020. Web. 18 Apr 2021.
Vancouver:
Montheil T. Conception d’hydrogels hybrides pour la préparation de géloses synthétiques : Design and synthesis of silylated hybrid hydrogels. [Internet] [Doctoral dissertation]. Montpellier; 2020. [cited 2021 Apr 18].
Available from: http://www.theses.fr/2020MONTS012.
Council of Science Editors:
Montheil T. Conception d’hydrogels hybrides pour la préparation de géloses synthétiques : Design and synthesis of silylated hybrid hydrogels. [Doctoral Dissertation]. Montpellier; 2020. Available from: http://www.theses.fr/2020MONTS012
22.
Milena Elias Teixeira.
Aplicação do eletrodo de diamante dopado com boro modificado pelo método Sol-Gel para determinação e degradação de carbaril.
Degree: 2012, University of São Paulo
URL: http://www.teses.usp.br/teses/disponiveis/75/75135/tde-19032013-164142/
► São apresentados os resultados do estudo das propriedades eletroquímicas do eletrodo de diamante dopado com boro (DDB) e do eletrodo de DDB modificado diretamente pelo…
(more)
▼ São apresentados os resultados do estudo das propriedades eletroquímicas do eletrodo de diamante dopado com boro (DDB) e do eletrodo de DDB modificado diretamente pelo método
Sol-
Gel com PbOx, para a determinação de carbaril. Mostrou-se que uma polarização anódica (3,0 V vs Ag/AgCl, 30 min) seguida de uma catódica (-3,0 V vs Ag/AgCl, 30 min), em meio ácido, são apropriadas para otimizar o desempenho catalítico da superfície. As imagens de AFM mostraram alterações topológicas significativas no eletrodo de PbOx/DDB, assim como as imagens digitais apresentaram uma provável mistura de óxidos de chumbo depositados na superfície do DDB. Caracterizações físicas do modificador PbOx foram realizadas com as técnicas de Microscopia Eletrônica de Varredura (MEV), Difratometria de raios-X (DRX) e Energia Dispersiva de raios-X (EDS). A MEV verificou os aspectos morfológicos da amostra e revelou que as partículas do modificador tinham formatos e tamanhos
diferentes, distribuídas irregularmente. O difratograma de DRX confirmou a existência de uma mistura de óxidos de chumbo, produzida pelo método
Sol-
Gel e a análise por EDS mostrou a presença dos elementos chumbo e oxigênio, com proporção atômica de 43:57 (Pb:O). Para a determinação eletroanalítica do pesticida carbaril, empregou-se a técnica de Voltametria de Onda Quadrada (SWV) em tampão Britton-Robinson 4,0 x 10-2 mol L-1 (pH 6,0), com acréscimo de alíquotas obtidas de uma solução estoque de carbaril 1,0 x 10-2 mol L-1 em acetonitrila. Os parâmetros utilizados foram: frequência de 10 s-1, amplitude de pulso de 100 mV, incremento de potencial de 2 mV, potencial de pré-tratamento catódico de -1,1 V no tempo de 10 s. Curvas analíticas foram apresentadas para os dois eletrodos, mostrando que o eletrodo de DDB apresentou um limite de detecção (LD) de 2,0 µmol L-1. Já o eletrodo PbOx/DDB, um LD de 0,9 µmol L-1, baixo o suficiente em relação ao limite máximo de resíduo
permitido pela ANVISA para a presença do pesticida em amostras de culturas agrícolas. A repetibilidade das medidas com o eletrodo de PbOx/DDB resultou em um desvio padrão relativo de 4,6% e a reprodutibilidade, em 5,2%. Em um estudo das velocidades de varredura, mostrou que a oxidação do carbaril é controlada por difusão e ocorre de maneira irreversível na superfície do eletrodo de PbOx/DDB. A técnica de SWV também foi aplicada em amostras reais de água artificialmente contaminadas de dois córregos da cidade de São Carlos - SP (Córrego Santa Maria do Leme e Córrego do Gregório), ambas tamponadas (pH 6,0), utilizando o eletrodo de PbOx/DDB. Com o objetivo de se comparar a precisão e a sensibilidade da SWV, foram obtidos espectros de UV-Vis em 280 nm e as correspondentes curvas analíticas para o carbaril em tampão BR e nas amostras dos córregos, num intervalo de concentrações de 5,0 x 10-6 a 3,5 x 10-5 mol L-1. O LD e o limite de quantificação (LQ) em solução tampão BR, calculados a
partir dos experimentos de SWV, foram de 0,9 x 10-6 mol L-1 e 7,44 x 10-6 mol L-1, respectivamente. Para a técnica de UV-Vis, o LD…
Advisors/Committee Members: Sergio Antonio Spinola Machado, Gilberto Maia, Margarida Juri Saeki, Hugo Barbosa Suffredini.
Subjects/Keywords: carbaril; eletrodo de DDB; Sol-Gel; BDD electrode; carbaryl; Sol-Gel
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Teixeira, M. E. (2012). Aplicação do eletrodo de diamante dopado com boro modificado pelo método Sol-Gel para determinação e degradação de carbaril. (Doctoral Dissertation). University of São Paulo. Retrieved from http://www.teses.usp.br/teses/disponiveis/75/75135/tde-19032013-164142/
Chicago Manual of Style (16th Edition):
Teixeira, Milena Elias. “Aplicação do eletrodo de diamante dopado com boro modificado pelo método Sol-Gel para determinação e degradação de carbaril.” 2012. Doctoral Dissertation, University of São Paulo. Accessed April 18, 2021.
http://www.teses.usp.br/teses/disponiveis/75/75135/tde-19032013-164142/.
MLA Handbook (7th Edition):
Teixeira, Milena Elias. “Aplicação do eletrodo de diamante dopado com boro modificado pelo método Sol-Gel para determinação e degradação de carbaril.” 2012. Web. 18 Apr 2021.
Vancouver:
Teixeira ME. Aplicação do eletrodo de diamante dopado com boro modificado pelo método Sol-Gel para determinação e degradação de carbaril. [Internet] [Doctoral dissertation]. University of São Paulo; 2012. [cited 2021 Apr 18].
Available from: http://www.teses.usp.br/teses/disponiveis/75/75135/tde-19032013-164142/.
Council of Science Editors:
Teixeira ME. Aplicação do eletrodo de diamante dopado com boro modificado pelo método Sol-Gel para determinação e degradação de carbaril. [Doctoral Dissertation]. University of São Paulo; 2012. Available from: http://www.teses.usp.br/teses/disponiveis/75/75135/tde-19032013-164142/
23.
Marília Vilela Salvador.
Impacto da razão entre alcóxissilanos contendo grupo amina e grupo nitrila nas propriedades físico-químicas das partículas submicrométricas de ormosil obtidas via Processo Sol-Gel com poli-heterocondensação.
Degree: 2017, University of São Paulo
URL: http://www.teses.usp.br/teses/disponiveis/18/18158/tde-19052017-085226/
► Partículas submicrométricas esféricas de sílica são tradicionalmente obtidas via processo sol-gel, em meio básico, levando a materiais com morfologia e área superficial bem definida. Contudo,…
(more)
▼ Partículas submicrométricas esféricas de sílica são tradicionalmente obtidas via processo sol-gel, em meio básico, levando a materiais com morfologia e área superficial bem definida. Contudo, poucos são os trabalhos reportados na literatura, que demonstram se esta mesma rota pode ser usada para se obter partículas organicamente modificadas em uma única etapa com o mesmo controle de morfologia e área superficial via reações de poli-heterocondensação de organo-alcoxisilanos contendo diferentes funcionalidades. Tais materiais são comumente chamados de materiais híbridos de classe II do tipo Silicatos Organicamente Modificados (Ormosils). Funcionalidade orgânicas do tipo nitrogenadas foram escolhidas para verificar a viabilidade desta rota sintética devido ao grande potencial destas como suportes catalíticos, adsorção de CO2, fases cromatográficas estacionárias polares e para cromatografia de afinidade, suportes para partículas fotocrômicas, e uso em
eletrodos quimicamente modificados. Tendo em vista que ormosils nitrogenados com grupos amino podem ser obtidos via utilização de aminopropiltrietoxisilano e para o espaçamento destes grupos uma escolha comum á a utilização de silanos contendo grupos nitrila, foram estudadas diversas formulações com diferente razão molar de 3-aminopropiltrietoxissilano (APTS) e 4-(trietóxisilil)butironitrila (BUTS). Os resultados mostraram que a premissa inicial de que o método de poli-heterocondensação em meio básico não pode ser utilizado indiscriminadamente para a obtenção de partículas submicrométricas esféricas é parcialmente correto, de fato apenas uma estreita faixa de concentração permite obter esta morfologia e desde que não esteja presente o BUTS. Este silano parece influenciar decisivamente na morfologia e na área superficial dos ormosils obtidos. Assim, a rota de poli-heterocondensação ou one-pot foi efetiva para obter partículas modificadas com grupos amino, mas não pode ser usada para
obter estas mesmas partículas modificadas com qualquer proporção de grupos nitrila. Todos os materiais híbridos sintetizados demonstraram capacidade de adsorção de hexaaquocobre(II) a partir de soluções aquosas podendo ser utilizados para aplicações que envolvem a sorção destes metais, por exemplo em hidrometalurgia ou remediação ambiental. Os estudos de RPE dos ormosils com Cu(II) mostraram que estes íons se adsorveram nos grupos amina, ou seja, estes estão acessíveis para reação com adsorbatos.Desta forma estes ormosils podem em trabalhos futuros ser explorados para imobilização de enzimas via ligação peptídica, adsorção de CO2 ou agente de reforço mecânico em compósitos com biopolímeros como quitosana, quitina, pectina, ácido algínico para uso em cosmetologia ou liberação controlada de nutrientes.
Silica Spherical sub-micrometric particles are often obtained by sol-gel processing in basic media. Nevertheless, a few works in the literature deals with the synthesis of particles
bearing different functionalities by poly-heterocondensation of silanes with different organic moieties.…
Advisors/Committee Members: Ubirajara Pereira Rodrigues Filho, Eder Tadeu Gomes Cavalheiro, Sidney José Lima Ribeiro.
Subjects/Keywords: Ormosil; Sílica organomodificada; Sol-Gel; Ormosil; Sílica organo-modified; Sol-Gel
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Salvador, M. V. (2017). Impacto da razão entre alcóxissilanos contendo grupo amina e grupo nitrila nas propriedades físico-químicas das partículas submicrométricas de ormosil obtidas via Processo Sol-Gel com poli-heterocondensação. (Masters Thesis). University of São Paulo. Retrieved from http://www.teses.usp.br/teses/disponiveis/18/18158/tde-19052017-085226/
Chicago Manual of Style (16th Edition):
Salvador, Marília Vilela. “Impacto da razão entre alcóxissilanos contendo grupo amina e grupo nitrila nas propriedades físico-químicas das partículas submicrométricas de ormosil obtidas via Processo Sol-Gel com poli-heterocondensação.” 2017. Masters Thesis, University of São Paulo. Accessed April 18, 2021.
http://www.teses.usp.br/teses/disponiveis/18/18158/tde-19052017-085226/.
MLA Handbook (7th Edition):
Salvador, Marília Vilela. “Impacto da razão entre alcóxissilanos contendo grupo amina e grupo nitrila nas propriedades físico-químicas das partículas submicrométricas de ormosil obtidas via Processo Sol-Gel com poli-heterocondensação.” 2017. Web. 18 Apr 2021.
Vancouver:
Salvador MV. Impacto da razão entre alcóxissilanos contendo grupo amina e grupo nitrila nas propriedades físico-químicas das partículas submicrométricas de ormosil obtidas via Processo Sol-Gel com poli-heterocondensação. [Internet] [Masters thesis]. University of São Paulo; 2017. [cited 2021 Apr 18].
Available from: http://www.teses.usp.br/teses/disponiveis/18/18158/tde-19052017-085226/.
Council of Science Editors:
Salvador MV. Impacto da razão entre alcóxissilanos contendo grupo amina e grupo nitrila nas propriedades físico-químicas das partículas submicrométricas de ormosil obtidas via Processo Sol-Gel com poli-heterocondensação. [Masters Thesis]. University of São Paulo; 2017. Available from: http://www.teses.usp.br/teses/disponiveis/18/18158/tde-19052017-085226/
24.
Franciani Cassia Sentanin.
Desenvolvimento de janelas eletrocrômicas.
Degree: 2013, University of São Paulo
URL: http://www.teses.usp.br/teses/disponiveis/88/88131/tde-25032015-151216/
► Este trabalho apresenta os resultados do preparo e caracterização de janelas eletrocrômicas (ECD) contendo filmes finos de WO3 como camada eletrocrômica, CeO2-TiO2 como contra-eletrodo e…
(more)
▼ Este trabalho apresenta os resultados do preparo e caracterização de janelas eletrocrômicas (ECD) contendo filmes finos de WO3 como camada eletrocrômica, CeO2-TiO2 como contra-eletrodo e eletrólitos a base de polímeros naturais plastificados. Os filmes finos de CeO2-TiO2 e WO3 foram preparados pelo processo sol-gel e usados para montagem de dispositivos (janelas) eletrocrômicas com variados eletrólitos poliméricos. Os filmes finos e as janelas foram caracterizados através de medidas de densidade de carga, voltametria cíclica e transmitância. Os filmes de CeO2-TiO2 e WO3 apresentaram respectivamente, valores de densidade de carga de 11,8 e 27,8 mC/cm2, e razão de carga anódica/catódica de 0,98 e 0,85. As análises voltamétricas dos filmes finos revelaram picos característicos dos processos de oxidação e redução e as análises espectroscópicas a transmitância de 80 e 78 %, respectivamente. Foram preparadas e caracterizadas janelas com eletrólitos a
base de gelatina com ácido acético; gelatina com LiI/I2; gelatina com agar; gelatina com líquidos iônicos; gelatina com líquidos iônicos e triflato de európio; poli(vinil butirato) (PVB) com LiI/I2; PVB com LiClO4; agar com LiClO4; agar com líquidos iônicos; DNA; DNA com LiClO4; DNA-cloreto de hexadeciltrimetilamônio (DNA-CTMA) com azul da Prússia; DNA com PEDOT:PSS (poli(3,4-etilenodioxitiofeno):poli(sulfonato de estireno)); DNA-CTMA com PEDOT:PSS. Os melhores resultados de densidade de carga de 5,4 e 6,0 mC/cm2 foram obtidas para os dispositivos com eletrólitos de gelatina com agar e agar com LiClO4. A razão de carga anódica/catódica desses dispositivos foi de 0,98 e 0,99. Os voltamogramas cíclicos das amostras estudadas revelaram picos anódicos e catódicos referentes à extração e inserção de íons lítio e elétrons no filme de WO3. As análises de transmitância em 550 nm entre o estado colorido e descolorido das janelas mostrou os valores de 28% para a janela contendo eletrólito a
base de PVB com LiI/I2. Além disso, também foi verificada a estabilidade dos dispositivos revelando a duração entre 100 a 400 ciclos cronoamperometricos, dependendo do eletrólito usado. Os resultados obtidos mostram que as janelas estudadas são potenciais candidatas às aplicações práticas.
This work presents the results of the preparation and characterization of electrochromic windows (ECD) containing thin films of WO3 as electrochromic layer, CeO2-TiO2 as the counter electrode and natural polymer-based electrolytes. Thin films of CeO2-TiO2 and WO3 were prepared by the sol-gel process and used to assembly the electrochromic devices (windows) with different polymer electrolytes. The thin films and windows samples were characterized by charge density, cyclic voltammetry and transmittance measurements. CeO2-TiO2 and WO3 thin films revealed charge density values of 11.8 and 27.8 mC/cm2, and anodic/cathodic charge relation of 0.98 and 0.85, respectively. The cyclic voltammograms
revealed the peaks characteristic of the processes of oxidation and reduction and the spectroscopic analysis the…
Advisors/Committee Members: Agnieszka Joanna Pawlicka Maule, Andréa Simone Stucchi de Camargo Alvarez Bernardez, Gilmara de Oliveira Machado, Artur de Jesus Motheo, Hebe de Las Mercedes Villullas.
Subjects/Keywords: dispositivos eletrocrômicos; eletrocromismo; sol-gel; electrochromic devices; electrochromism; sol-gel
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Sentanin, F. C. (2013). Desenvolvimento de janelas eletrocrômicas. (Doctoral Dissertation). University of São Paulo. Retrieved from http://www.teses.usp.br/teses/disponiveis/88/88131/tde-25032015-151216/
Chicago Manual of Style (16th Edition):
Sentanin, Franciani Cassia. “Desenvolvimento de janelas eletrocrômicas.” 2013. Doctoral Dissertation, University of São Paulo. Accessed April 18, 2021.
http://www.teses.usp.br/teses/disponiveis/88/88131/tde-25032015-151216/.
MLA Handbook (7th Edition):
Sentanin, Franciani Cassia. “Desenvolvimento de janelas eletrocrômicas.” 2013. Web. 18 Apr 2021.
Vancouver:
Sentanin FC. Desenvolvimento de janelas eletrocrômicas. [Internet] [Doctoral dissertation]. University of São Paulo; 2013. [cited 2021 Apr 18].
Available from: http://www.teses.usp.br/teses/disponiveis/88/88131/tde-25032015-151216/.
Council of Science Editors:
Sentanin FC. Desenvolvimento de janelas eletrocrômicas. [Doctoral Dissertation]. University of São Paulo; 2013. Available from: http://www.teses.usp.br/teses/disponiveis/88/88131/tde-25032015-151216/
25.
Fernandes, Mariana Sofia Peixoto.
Multifuncional organic/inorganic hybrids prepared through sol-gel and/or self-assembly.
Degree: 2014, RCAAP
URL: http://www.rcaap.pt/detail.jsp?id=oai:http://repositorio.utad.pt/:10348/3191
► Tese de Doutoramento em Química
Esta tese centra-se na preparação de sistemas híbridos orgânicos-inorgânicos com propriedades específicas. Na primeira parte do trabalho utilizaram-se o processo…
(more)
▼ Tese de Doutoramento em Química
Esta tese centra-se na preparação de sistemas híbridos orgânicos-inorgânicos com propriedades específicas.
Na primeira parte do trabalho utilizaram-se o processo sol-gel e metodologias de auto-organização na preparação de materiais híbridos orgânicos-inorgânicos. Esta conjugação de métodos de síntese é particularmente interessante, não só do ponto de vista fundamental, mas também porque permite a produção de novos materiais híbridos, hierarquicamente estruturados e funcionalizáveis. Obtiveram-se duas famílias distintas de amostras, cuja principal diferença reside na natureza do nó de ligação entre os componentes orgânico e inorgânico: grupo ureia e grupo uretano. A influência exercida na estruturação dos materiais por parâmetros, tais como o comprimento da cadeia de tipo alquilo (pendente ou em ponte) e o tipo de solvente, foi analisada.
Na segunda parte do trabalho o método sol-gel foi usado na preparação de electrólitos híbridos orgânicos-inorgânicos inovadores. Foi preparada uma matriz biohíbrida de poly(-caprolactona)/siloxano, baseada em nós de ligação de uretano. A matrizfoi dopada com uma gama de concentrações de triflato de potássio muito ampla, num caso, e com misturas de triflato de lítio/triflato de európio no segundo caso. Para ambos sistemas foram construídos protótipos de dispositivos electrocrómicos. Estes foram construídos usando-se uma configuração de tipo “sandwish” de quatro camadas, envolvendo duas camadas de filme de óxido condutor transparente, um filme de óxido de tungsténio (WO3) e uma camada activa condutora iónica de um ormolito de composição optimizada. A transmitância óptica, o contraste de cor, a densidade óptica, e o tempo de resposta do dispositivo associado ao processo de coloração/descoloração foram determinados. A variação de cor foi quantificada para o protótipo cujo ormolito contém uma mistura de triflato de lítio/triflato de európio,
O carbonato de cálcio (CaCO3) é um dos biominerais mais importantes na Natureza. Pode existir em seis formas polimórficas diferentes. De entre estas a fase metastável amorfa (carbonato de cálcio amorfo, CCA) é usada por muitos organismos
como uma fase intermediária transiente para a formação de cristais de calcite e aragonite exibindo formas elaboradas. Uma das potenciais aplicações do CCA encontra-se no domínio da ortopedia.. Neste trabalho utilizou-se a poli(vinilpirrolidona) para retardar a cristalização do CCA. Foram ainda usados diferentes líquidos iónicos e tensioactivos para controlar a morfologia de calcite.
This thesis is focused on the preparation of organic-inorganic hybrid systems with targeted properties.
In the first part of the work, the sol-gel process and self-assembly techniques were employed for the preparation of organic-inorganic hybrid materials. This combination is of great interest, not only from the fundamental point of view, but also because it allows the production of novel functional and hierarchically structured hybrid materials. Two families of materials were obtained, featuring two…
Advisors/Committee Members: Zea Bermudez, Verónica de.
Subjects/Keywords: Processo sol-gel; Dispositivos electrocrómicos; Biomineralização
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Fernandes, M. S. P. (2014). Multifuncional organic/inorganic hybrids prepared through sol-gel and/or self-assembly. (Thesis). RCAAP. Retrieved from http://www.rcaap.pt/detail.jsp?id=oai:http://repositorio.utad.pt/:10348/3191
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Fernandes, Mariana Sofia Peixoto. “Multifuncional organic/inorganic hybrids prepared through sol-gel and/or self-assembly.” 2014. Thesis, RCAAP. Accessed April 18, 2021.
http://www.rcaap.pt/detail.jsp?id=oai:http://repositorio.utad.pt/:10348/3191.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Fernandes, Mariana Sofia Peixoto. “Multifuncional organic/inorganic hybrids prepared through sol-gel and/or self-assembly.” 2014. Web. 18 Apr 2021.
Vancouver:
Fernandes MSP. Multifuncional organic/inorganic hybrids prepared through sol-gel and/or self-assembly. [Internet] [Thesis]. RCAAP; 2014. [cited 2021 Apr 18].
Available from: http://www.rcaap.pt/detail.jsp?id=oai:http://repositorio.utad.pt/:10348/3191.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Fernandes MSP. Multifuncional organic/inorganic hybrids prepared through sol-gel and/or self-assembly. [Thesis]. RCAAP; 2014. Available from: http://www.rcaap.pt/detail.jsp?id=oai:http://repositorio.utad.pt/:10348/3191
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

NSYSU
26.
Ting, Wei-He.
Prepare PZT powder by sol-gel method.
Degree: Master, Materials Science and Engineering, 2001, NSYSU
URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0116101-143512
Prepare PZT powder by sol-gel method.Acid and ester amounts will effect microstructure by sol-gel method.
Advisors/Committee Members: Tzu-chien Hsu (committee member), Bing-Hwait Hwang (chair), Hong-Yang Lu (chair).
Subjects/Keywords: pzt; sol-gel
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Ting, W. (2001). Prepare PZT powder by sol-gel method. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0116101-143512
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Ting, Wei-He. “Prepare PZT powder by sol-gel method.” 2001. Thesis, NSYSU. Accessed April 18, 2021.
http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0116101-143512.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Ting, Wei-He. “Prepare PZT powder by sol-gel method.” 2001. Web. 18 Apr 2021.
Vancouver:
Ting W. Prepare PZT powder by sol-gel method. [Internet] [Thesis]. NSYSU; 2001. [cited 2021 Apr 18].
Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0116101-143512.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Ting W. Prepare PZT powder by sol-gel method. [Thesis]. NSYSU; 2001. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0116101-143512
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

NSYSU
27.
Yu, Chun-cheng.
Magnetic and crystal structure transition on La0.2Ho0.8Mn2O5 oxide.
Degree: Master, Physics, 2009, NSYSU
URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0213109-112553
► La doped HoMn2O5 in studying the influence of the local structure distortion on the magnetic transition has been investigated systematically. It is found that by…
(more)
▼ La doped HoMn2O5 in studying the influence of the local structure distortion on the magnetic transition has been investigated systematically. It is found that by doping of La ions in a proper percentage, 0.1≤x≤0.2, the formation of the possible impurity RMnO3 (113) phase could be suppressed; single phases of LaxHo1-xMn2O5 (0.1≤x≤0.2) can be formed in one atmosphere of flowing oxygen. For x=0.2, an weak ferromagnetic transition on top of the paramagnetic background appears at 150K and saturated at 75K, which implies that the compound undergoes a ferromagnetic to antiferromagnetic transition. In addition, the lattice didnât appear a huge phase transition at low temperature, itâs observed local distortion behavior within 100~150K, and back to normal structure as high temperature ones. Itâs convinced that will be associated with the magnetic properties, which need further examination and experiment.
Advisors/Committee Members: Shih-Jye Sun (chair), Hsiung Chou (committee member), Hung-Duen Yang (chair).
Subjects/Keywords: GSAS; phase transition; Jana; Multiferroic; sol-gel
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Yu, C. (2009). Magnetic and crystal structure transition on La0.2Ho0.8Mn2O5 oxide. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0213109-112553
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Yu, Chun-cheng. “Magnetic and crystal structure transition on La0.2Ho0.8Mn2O5 oxide.” 2009. Thesis, NSYSU. Accessed April 18, 2021.
http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0213109-112553.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Yu, Chun-cheng. “Magnetic and crystal structure transition on La0.2Ho0.8Mn2O5 oxide.” 2009. Web. 18 Apr 2021.
Vancouver:
Yu C. Magnetic and crystal structure transition on La0.2Ho0.8Mn2O5 oxide. [Internet] [Thesis]. NSYSU; 2009. [cited 2021 Apr 18].
Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0213109-112553.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Yu C. Magnetic and crystal structure transition on La0.2Ho0.8Mn2O5 oxide. [Thesis]. NSYSU; 2009. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0213109-112553
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

NSYSU
28.
Chen, I-cheng.
The multifunctional fiber platform made by sol-gel process.
Degree: Master, Electro-Optical Engineering, 2015, NSYSU
URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0527115-194428
► With emergence of the demand for functional fiber, there are many fiber appeared in succession, such as optical fiber sensors, optical amplifiers, fiber grating, etc.…
(more)
▼ With emergence of the demand for functional fiber, there are many fiber appeared in succession, such as optical fiber sensors, optical amplifiers, fiber grating, etc. Those fibers indicate the development of optical fiber platform for multifunction will be inevitable. Therefore, we want to study a new fiber preparation for building an optical fiber which could make more materials or elements exist in one fiber.
We use
sol-
gel method to prepare the fiber. Comparing to the main processes, such as MCVD [1], and OVD [2],
sol-
gel process have lower heat treatment temperature, and provide a chemical reaction or physically mixed environment. Low temperature process could avoid to destroy chemical structure of some materials in the fiber and reduce the effect of heat treatment to the fiber elements.
We chose PTFE tube as cladding, melting
gel as core. And we added esters to form network structure, it could reduce the number of gaps. Furthermore, we added fluorescent material, neodymium nitrate and neodymium oxide nano-particles into melting
gel. The fluorescent of samples of neodymium oxide nano-particles in melting
gel had been confirmed by PL. But some noise will be excited by defect. We could improve noise by SCCO2. Furthermore we modified the neodymium oxide nano-particles by methyldichlorosilane (DMDCS)[3]. The neodymium oxide nano-particles modified by DMDCS could reduce background absorption coefficient, and keep the absorption peaks of Nd3+. It made the gain greater than the loss be possible.
Our processes has elderly activity that could change composition of cladding and core to build functional fiber. And we will add different functional substance into melting
gel to make mult-functional fibers possible. The fibers could be used in optical communications.
Advisors/Committee Members: Jimmy Wang (committee member), Ying-Lang Wang (chair), Ting-Chang Chang (chair).
Subjects/Keywords: fiber; sol-gel; modified; SCCO2; fluorescent
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Chen, I. (2015). The multifunctional fiber platform made by sol-gel process. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0527115-194428
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Chen, I-cheng. “The multifunctional fiber platform made by sol-gel process.” 2015. Thesis, NSYSU. Accessed April 18, 2021.
http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0527115-194428.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Chen, I-cheng. “The multifunctional fiber platform made by sol-gel process.” 2015. Web. 18 Apr 2021.
Vancouver:
Chen I. The multifunctional fiber platform made by sol-gel process. [Internet] [Thesis]. NSYSU; 2015. [cited 2021 Apr 18].
Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0527115-194428.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Chen I. The multifunctional fiber platform made by sol-gel process. [Thesis]. NSYSU; 2015. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0527115-194428
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

NSYSU
29.
LIN, CHENG-KUO.
Evanescent wave fiber optic PH sensor in Biomedical Application.
Degree: Master, Electro-Optical Engineering, 2012, NSYSU
URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0903112-035623
► People to feel more and more attention to health, the pursuit of high quality of life, biomedical sensing is one of the development of technology,…
(more)
▼ People to feel more and more attention to health, the pursuit of high quality of life, biomedical sensing is one of the development of technology, person to understand the current state of health, currently known as blood sugar and blood pressure monitors, to track health status
of the instrument is obvious too inadequate, usually go to the hospital for examination, but it is quite time-consuming, ranging from a waste of time, so the immediate biomedical optical fiber sensor to do direction. Evanescent wave ways to do research for my use of the sensing material-specific dye, sensing agent in different situations will be absorbed to change the situation, the use of
sol-
gel method (
Sol-
Gel) to
coated with the specific dye, to make our fiber clothes (cladding), when the light in optical fibers, through the specific dye to change the energy of light in optical fibers.
Advisors/Committee Members: Tsung-Hsien Lin (chair), Jan-Sheng Wang (committee member), Ming-Chang Shih (chair), Chin-Ping Yu (chair).
Subjects/Keywords: plastic optical fiber; pH; the SOL-GEL
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
LIN, C. (2012). Evanescent wave fiber optic PH sensor in Biomedical Application. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0903112-035623
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
LIN, CHENG-KUO. “Evanescent wave fiber optic PH sensor in Biomedical Application.” 2012. Thesis, NSYSU. Accessed April 18, 2021.
http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0903112-035623.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
LIN, CHENG-KUO. “Evanescent wave fiber optic PH sensor in Biomedical Application.” 2012. Web. 18 Apr 2021.
Vancouver:
LIN C. Evanescent wave fiber optic PH sensor in Biomedical Application. [Internet] [Thesis]. NSYSU; 2012. [cited 2021 Apr 18].
Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0903112-035623.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
LIN C. Evanescent wave fiber optic PH sensor in Biomedical Application. [Thesis]. NSYSU; 2012. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0903112-035623
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
30.
Sidi-Ali, Fatiha.
Synthèse et caractérisation de catalyseurs nanostructurés à base d’oxydes de (Ce, Mo, Al et Si) par pulvérisation du sol.
Degree: 2013, Université M'Hamed Bougara Boumerdès
URL: http://dlibrary.univ-boumerdes.dz:8080123456789/1412
► 92 p. : ill. ; 30 cm
L'objectif de ce travail est d'étudier la synthèse et la caractérisation des catalyseurs nanostructurés constitués de l'association de…
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▼ 92 p. : ill. ; 30 cm
L'objectif de ce travail est d'étudier la synthèse et la caractérisation des catalyseurs nanostructurés constitués de l'association de nanoparticules d'oxydes de métaux et d'évaluer leurs propriétés catalytiques. Quatre types de catalyseurs nanostructurés ont été synthétisés par la méthode sol-gel en milieu basique à savoir : Al2O3-SiO2, MoO2-Al2O3-SiO2, CeO2-Al2O3-SiO2, et MoO2-CeO2-Al2O3-SiO2 par pulvérisation de sol à haute température. Ces catalyseurs ont été caractérisés par différentes méthodes physicochimiques telles que la microscopie électronique à transmission (MET), la diffraction des rayons X (DRX), la spectroscopie infrarouge à transformée de Fourier (FTIR), l'analyse de surface par adsorption de N2 (BET) et la zêtamétrie (pour l'étude de la stabilité du sol colloïdal)
Subjects/Keywords: Sol-gel, Procédé; Oxydes; Matériaux nanostructurés; Catalyse
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APA (6th Edition):
Sidi-Ali, F. (2013). Synthèse et caractérisation de catalyseurs nanostructurés à base d’oxydes de (Ce, Mo, Al et Si) par pulvérisation du sol. (Thesis). Université M'Hamed Bougara Boumerdès. Retrieved from http://dlibrary.univ-boumerdes.dz:8080123456789/1412
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Sidi-Ali, Fatiha. “Synthèse et caractérisation de catalyseurs nanostructurés à base d’oxydes de (Ce, Mo, Al et Si) par pulvérisation du sol.” 2013. Thesis, Université M'Hamed Bougara Boumerdès. Accessed April 18, 2021.
http://dlibrary.univ-boumerdes.dz:8080123456789/1412.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Sidi-Ali, Fatiha. “Synthèse et caractérisation de catalyseurs nanostructurés à base d’oxydes de (Ce, Mo, Al et Si) par pulvérisation du sol.” 2013. Web. 18 Apr 2021.
Vancouver:
Sidi-Ali F. Synthèse et caractérisation de catalyseurs nanostructurés à base d’oxydes de (Ce, Mo, Al et Si) par pulvérisation du sol. [Internet] [Thesis]. Université M'Hamed Bougara Boumerdès; 2013. [cited 2021 Apr 18].
Available from: http://dlibrary.univ-boumerdes.dz:8080123456789/1412.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Sidi-Ali F. Synthèse et caractérisation de catalyseurs nanostructurés à base d’oxydes de (Ce, Mo, Al et Si) par pulvérisation du sol. [Thesis]. Université M'Hamed Bougara Boumerdès; 2013. Available from: http://dlibrary.univ-boumerdes.dz:8080123456789/1412
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
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