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University of New Orleans
1.
Rostamzadeh, Taha.
Engineering Nanoarchitectures from Nanosheets, Nanoscrolls, and Nanoparticles.
Degree: PhD, Chemistry, 2016, University of New Orleans
URL: https://scholarworks.uno.edu/td/2229
► The ability to encapsulate/insert different kinds of nanoparticles (NPs) in scrolled nanosheets (NSs) may lead to the formation of new nanocomposite materials that yield…
(more)
▼ The ability to encapsulate/insert different kinds of nanoparticles (NPs) in scrolled
nanosheets (NSs) may lead to the formation of new nanocomposite materials that yield novel properties. These nanostructures resemble “peapods” that consist of NPs chains (“peas”) located in a hollow space of desired nanoscrolls (“pods”). Depending on different combinations of “peas” and “pods” diverse families of nanopeapods (NPPs) can be synthesized which may exhibit interesting properties not accessible from the individual components. Though there exist various synthetic methods for the formation of NPPs, more development in terms of simplicity, flexibility, and productivity of synthetic approaches are needed so that different classes of NPPs with unique combinations/characteristics of “peas” and “pods” can be synthesized.
A simple solvothermal synthesis method for the encapsulation of spherical Fe
3O
4 NPs by the capture of preformed NPs in scrolled hexaniobate has previously been developed in our group. In the first part of this research, efforts were made to extend the “pod” materials to other
inorganic NScs. Vanadate nanoscrolls (NScs) could rapidly (2h) be produced using a simple solvothermal treatment in the presence of V
2O
5 as vanadium source, and either dodecylamine (DDA) or octadecylamine (ODA) as the structure-directing agent. The synthesis parameters were successfully adjusted to obtain high yields vanadate NScs (~ 20 g of NScs per synthesis) with different average lengths as 383 nm, 816 nm to 3.3 µm. The effects of reaction time on the formation of NScs were also investigated.
Further efforts focused on the development of methods for making vanadate NPPs. Here, two novel approaches for the formation of these NPPs have been successfully developed. In the first, solvothermal methods utilizing preformed Ag NPs and vanadate NSs lead to the formation of
[email protected] NPPs where NPs could be encapsulated during the scrolling of NSs. High NP loadings were acquired with this approach. In the second method, an insertion strategy was developed where Ag NPs were drawn into the lumen of preformed vanadate NScs upon controlled solvent evaporation. This method was also quite effective, though much lower loadings of NPs were achieved with larger average NP-NP distances. Also noteworthy in the study of vanadate NScs and NPPs is the observation of an uncommon asymmetric scrolling behavior; this was realized for both vanadate NScs and solvothermally synthesized
[email protected] NPPs.
Novel solvothermal approaches for the effective construction of organic-MoO
x hybrid structures and MoO
x nanosheets (NSs) have also been developed. These NSs can be controlled so as to exist in different oxidation states as well as in different crystal structures. Layer spacing as a function of organic molecule lengths could also be controlled by changing the type of surfactants located between the NSs. Individual NSs or a few layers of stacked NSs, up to four micrometers in…
Advisors/Committee Members: John B. Wiley.
Subjects/Keywords: Nanocomposites, Nanopeapods, Nanoparticles, Nanosheets, Nanoscrolls, Vanadate, Hexaniobate, MoOx; Inorganic Chemistry; Materials Chemistry
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APA (6th Edition):
Rostamzadeh, T. (2016). Engineering Nanoarchitectures from Nanosheets, Nanoscrolls, and Nanoparticles. (Doctoral Dissertation). University of New Orleans. Retrieved from https://scholarworks.uno.edu/td/2229
Chicago Manual of Style (16th Edition):
Rostamzadeh, Taha. “Engineering Nanoarchitectures from Nanosheets, Nanoscrolls, and Nanoparticles.” 2016. Doctoral Dissertation, University of New Orleans. Accessed January 16, 2021.
https://scholarworks.uno.edu/td/2229.
MLA Handbook (7th Edition):
Rostamzadeh, Taha. “Engineering Nanoarchitectures from Nanosheets, Nanoscrolls, and Nanoparticles.” 2016. Web. 16 Jan 2021.
Vancouver:
Rostamzadeh T. Engineering Nanoarchitectures from Nanosheets, Nanoscrolls, and Nanoparticles. [Internet] [Doctoral dissertation]. University of New Orleans; 2016. [cited 2021 Jan 16].
Available from: https://scholarworks.uno.edu/td/2229.
Council of Science Editors:
Rostamzadeh T. Engineering Nanoarchitectures from Nanosheets, Nanoscrolls, and Nanoparticles. [Doctoral Dissertation]. University of New Orleans; 2016. Available from: https://scholarworks.uno.edu/td/2229

Indian Institute of Science
2.
Chalasani, Rajesh.
Functionalized Nanostructures : Iron Oxide Nanocrystals and Exfoliated Inorganic Nanosheets.
Degree: PhD, Faculty of Science, 2018, Indian Institute of Science
URL: http://etd.iisc.ac.in/handle/2005/3463
► This thesis consists of two parts. The first part deals with the magnetic properties of Fe3O4 nanocrystals and their possible application in water remediation. The…
(more)
▼ This thesis consists of two parts. The first part deals with the magnetic properties of Fe3O4 nanocrystals and their possible application in water remediation. The second part is on the delamination of layered materials and the preparation of new layered hybrids from the delaminated sheets.
In recent years, nanoscale magnetic particles have attracted considerable attention because of their potential applications in industry, medicine and environmental remediation. The most commonly studied magnetic nanoparticles are metals, bimetals and metal oxides. Of these, magnetite, Fe3O4, nanoparticles have been the most intensively investigated as they are, non-toxic, stable and easy to synthesize. Magnetic properties of nanoparticles such as the saturation magnetization, coercivity and blocking temperature are influenced both by size and shape. Below a critical size magnetic particles can become single domain and above a critical temperature (T B , the blocking temperature) thermal fluctuations can induce random flipping of magnetic moments resulting in loss of magnetic order. At temperatures above the blocking temperature the particles are superparamagnetic. Magnetic nanocrystals of similar dimensions but with different shapes show variation in magnetic properties especially in the value of the blocking temperature, because of differences in the surface anisotropy contribution. The properties of magnetic nanoparticles are briefly reviewed in Chapter 1. The objective of the present study was to synthesize Fe3O4 nanocrystals of different morphologies, to understand the difference in magnetic properties associated with shape and to explore the possibility of using Fe3O4 nanocrystals in water remediation.
In the present study, oleate capped magnetite (Fe3O4) nanocrystals of spherical and cubic morphologies of comparable dimensions (∼10nm) have been synthesized by thermal decomposition of FeOOH in high-boiling octadecene solvent (Chapter 2). The nanocrystals were characterized by XRD, TEM and XPS spectroscopy. The nanoparticles of different morphologies exhibit very different blocking temperatures. Cubic nanocrystals have a higher blocking temperature (T B = 190 K) as compared to spheres (T B = 142 K). From the shift in the hysteresis loop it is demonstrated that the higher blocking temperature is a consequence of exchange bias or exchange anisotropy that manifests when a ferromagnetic material is in physical contact with an antiferromagnetic material. In nanoparticles, the presence of an exchange bias field leads to higher blocking temperatures T B because of the magnetic exchange coupling induced at the interface between the ferromagnet and antiferromagnet. It is shown that in these iron oxide nanocrystals the exchange bias field originates from trace amounts of the antiferromagnet wustite, FeO, present along with the ferrimagnetic Fe3O4 phase. It is also shown that the higher FeO content in nanocrystals of cubic morphology is responsible for the larger exchange bias fields that in turn lead to a higher blocking temperature.…
Advisors/Committee Members: Vasudevan, S (advisor).
Subjects/Keywords: Nanostructures; Iron Oxide Nanocrystals; Exfoliated Inorgnaic Nanosheets; Iron Oxide Nanocrystals; Magnetic Nanocrystals; Magnetic Nanoparticles; Magnetic Iron Oxide Nanocrystals; Magnetic Nanoparticles; Surfactant Intercalation; Layered Materials - Delamination; [email protected]; Inorganic Nanosheets; Layered Double Hydroxide; Oleate Capped Magnetite Nanocrystals; Nanotechnology
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Chalasani, R. (2018). Functionalized Nanostructures : Iron Oxide Nanocrystals and Exfoliated Inorganic Nanosheets. (Doctoral Dissertation). Indian Institute of Science. Retrieved from http://etd.iisc.ac.in/handle/2005/3463
Chicago Manual of Style (16th Edition):
Chalasani, Rajesh. “Functionalized Nanostructures : Iron Oxide Nanocrystals and Exfoliated Inorganic Nanosheets.” 2018. Doctoral Dissertation, Indian Institute of Science. Accessed January 16, 2021.
http://etd.iisc.ac.in/handle/2005/3463.
MLA Handbook (7th Edition):
Chalasani, Rajesh. “Functionalized Nanostructures : Iron Oxide Nanocrystals and Exfoliated Inorganic Nanosheets.” 2018. Web. 16 Jan 2021.
Vancouver:
Chalasani R. Functionalized Nanostructures : Iron Oxide Nanocrystals and Exfoliated Inorganic Nanosheets. [Internet] [Doctoral dissertation]. Indian Institute of Science; 2018. [cited 2021 Jan 16].
Available from: http://etd.iisc.ac.in/handle/2005/3463.
Council of Science Editors:
Chalasani R. Functionalized Nanostructures : Iron Oxide Nanocrystals and Exfoliated Inorganic Nanosheets. [Doctoral Dissertation]. Indian Institute of Science; 2018. Available from: http://etd.iisc.ac.in/handle/2005/3463

Indian Institute of Science
3.
Arunachalam, Vaishali.
Aqueous and Non-aqueous Dispersions of Graphene and Boron Nitride Nanosheets : NMR Measurements and Molecular Dynamics Simulations.
Degree: PhD, Faculty of Science, 2019, Indian Institute of Science
URL: http://etd.iisc.ac.in/handle/2005/4306
► Preface Ever since the discovery of graphene in 2004, there has been considerable interest in two dimensional (2D) nanomaterials due to their distinctive properties and…
(more)
▼ Preface
Ever since the discovery of graphene in 2004, there has been considerable interest in
two dimensional (2D) nanomaterials due to their distinctive properties and the prospect
of potential applications. A 2D-nanomaterial may be obtained from the bulk layered
material by procedures that can overcome the van der Waals attractive force that hold
adjacent layers together. Historically this was first achieved by micro-mechanical cleavage
by the deceptively simple procedure of peeling atomically thin single layers from the bulk
material using scotch tape. The procedure, unfortunately, is not scalable and consequently
alternate procedures, both top-down as well as bottom-up, have been extensively explored.
One of the simplest methods to obtain defect-free 2D
nanosheets is the sonication assisted
liquid phase exfoliation of the bulk layered material in a suitable solvent.
The role of the solvent is crucial to the liquid phase exfoliation process, as the formation of stable dispersions require that the exfoliated sheets, produced on sonication,
be prevented from re-aggregating. A wide range of solvents, solvent mixtures and
surfactant solutions have been investigated and solvent systems that favour formation
of stable dispersions identified. Much of the current understanding of the role of the
solvent is based on phenomenological models, matching surface energies of the solvent
and the layered material so as to minimize the surface tension between the two. What has
remained elusive, however, is a molecular perspective of the nature of interactions between
the solvent and the exfoliated nanosheet. This the focus of the present study. This thesis
reports results of investigations on dispersions of graphene in aqueous and non-aqueous
media as well as dispersions of boron nitride in water using solution and solid-state
Nuclear Magnetic Resonance (NMR) spectroscopy aided by Molecular Dynamics (MD)
simulations for interpreting the experimental observations.
The thesis is organized as five chapters with Chapter 1 providing a brief overview
of 2D nanomaterials with focus on graphene and boron nitride (BN); their properties
and applications. The chapter discusses the methods for obtaining graphene and BN
nanosheets with emphasis on the sonication assisted liquid phase exfoliation approach.
The chapter also provides a brief review of the phenomenological models that have
been advanced to understand the stability of dispersions of 2D nanomaterials in different
solvents. The stability of the nanosheet dispersions require that solvent or ligand molecules
be in close association with the
nanosheets with properties and mobilities quite different
from those of the bulk solvent molecules. The challenge for in-situ measurements is to
be able to probe the bound or associated solvent/ ligand molecules in the presence of a
large excess of the bulk. NMR methods from the solution chemists toolbox are known to
provide methodologies that can distinguish bound ligand molecules from those in the bulk
and are,…
Advisors/Committee Members: Vasudevan, S (advisor).
Subjects/Keywords: Graphene; Boron Nitride Nanosheets; 2D Nanomaterials; Two Dimensional Nanomaterials; Graphene-Solvent Interactions; Graphene-Surfactant Interactions; Graphene-NMP Interactions; Inorganic and Physical Chemistry
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Arunachalam, V. (2019). Aqueous and Non-aqueous Dispersions of Graphene and Boron Nitride Nanosheets : NMR Measurements and Molecular Dynamics Simulations. (Doctoral Dissertation). Indian Institute of Science. Retrieved from http://etd.iisc.ac.in/handle/2005/4306
Chicago Manual of Style (16th Edition):
Arunachalam, Vaishali. “Aqueous and Non-aqueous Dispersions of Graphene and Boron Nitride Nanosheets : NMR Measurements and Molecular Dynamics Simulations.” 2019. Doctoral Dissertation, Indian Institute of Science. Accessed January 16, 2021.
http://etd.iisc.ac.in/handle/2005/4306.
MLA Handbook (7th Edition):
Arunachalam, Vaishali. “Aqueous and Non-aqueous Dispersions of Graphene and Boron Nitride Nanosheets : NMR Measurements and Molecular Dynamics Simulations.” 2019. Web. 16 Jan 2021.
Vancouver:
Arunachalam V. Aqueous and Non-aqueous Dispersions of Graphene and Boron Nitride Nanosheets : NMR Measurements and Molecular Dynamics Simulations. [Internet] [Doctoral dissertation]. Indian Institute of Science; 2019. [cited 2021 Jan 16].
Available from: http://etd.iisc.ac.in/handle/2005/4306.
Council of Science Editors:
Arunachalam V. Aqueous and Non-aqueous Dispersions of Graphene and Boron Nitride Nanosheets : NMR Measurements and Molecular Dynamics Simulations. [Doctoral Dissertation]. Indian Institute of Science; 2019. Available from: http://etd.iisc.ac.in/handle/2005/4306
4.
Akbarian-Tefaghi, Sara.
Microwave-Assisted Topochemical Manipulation of Layered Oxide Perovskites: From Inorganic Layered Oxides to Inorganic-Organic Hybrid Perovskites and Functionalized Metal-Oxide Nanosheets.
Degree: PhD, Chemistry, 2017, University of New Orleans
URL: https://scholarworks.uno.edu/td/2287
► Developing new materials with desired properties is a vital component of emerging technologies. Functional hybrid compounds make an important class of advanced materials that…
(more)
▼ Developing new materials with desired properties is a vital component of emerging technologies. Functional hybrid compounds make an important class of advanced materials that let us synergistically utilize the key features of the organic and
inorganic counterparts in a single composite, providing a very strong tool to develop new materials with ”engineered” properties. The research presented here, summarizes efforts in the development of facile and efficient methods for the fabrication of three- and two-dimensional
inorganic-organic hybrids based on layered oxide perovskites. Microwave radiation was exploited to rapidly fabricate and modify new and known materials. Despite the extensive utilization of microwaves in organic syntheses as well as the fabrication of the
inorganic solids, the work herein was among the first reported that used microwaves in topochemical modification of the layered oxide perovskites. Our group specifically was the first to perform rapid microwave-assisted reactions in all of the modification steps including proton exchange, grafting, intercalation, and exfoliation, which decreased the duration of multi-step modification procedures from weeks to only a few hours. Microwave-assisted grafting and intercalation reactions with n-alkyl alcohols and n-alkylamines, respectively, were successfully applied on double-layered Dion-Jacobson and Ruddlesden-Popper phases (HLaNb
2O
7, HPrNb
2O
7, and H
2CaTa
2O
7), and with somewhat more limited reactivity, applied to triple-layered perovskites (HCa
2Nb
3O
10 and H
2La
2Ti
3O
10). Performing neutron diffraction on n-propoxy-LaNb
2O
7, structure refinement of a layered hybrid oxide perovskite was then tried for the first time. Furthermore, two-dimensional hybrid oxides were efficiently prepared from HLnNb
2O
7 (Ln = La, Pr), HCa
2Nb
3O
10, HCa
2Nb
2FeO
9, and HLaCaNb
2MnO
10, employing facile microwave-assisted exfoliation and post-exfoliation surface-modification reactions for the first time. A variety of surface groups, saturated or unsaturated linear and cyclic organics, were successfully anchored onto these oxide
nanosheets. Properties of various functionalized metal-oxide
nanosheets, as well as the polymerization of some monomer-grafted
nanosheets, were then investigated for the two-dimensional hybrid systems.
Advisors/Committee Members: John B. Wiley, Matthew A. Tarr, Mark L. Trudell.
Subjects/Keywords: topochemical manipulation; layered oxide perovskites; microwave-assisted reactions; inorganic-organic hybrids; surface modification; functionalized metal-oxide nanosheets; Inorganic Chemistry; Materials Chemistry; Polymer Chemistry
…2.2.2 Synthesis of the Inorganic Hosts… …97
Chapter 4. Rapid Exfoliation and Surface-Tailoring of Perovskite Nanosheets via… …104
4.2.2 Synthesis of Inorganic Hosts… …106
4.2.5 Surface Exchange of Nanosheets with n-Alkyl Alcohols and n-Alkylamines… …107
4.2.6 Exchange of Nanosheets with Other Organic Surface Groups .................... 107…
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Akbarian-Tefaghi, S. (2017). Microwave-Assisted Topochemical Manipulation of Layered Oxide Perovskites: From Inorganic Layered Oxides to Inorganic-Organic Hybrid Perovskites and Functionalized Metal-Oxide Nanosheets. (Doctoral Dissertation). University of New Orleans. Retrieved from https://scholarworks.uno.edu/td/2287
Chicago Manual of Style (16th Edition):
Akbarian-Tefaghi, Sara. “Microwave-Assisted Topochemical Manipulation of Layered Oxide Perovskites: From Inorganic Layered Oxides to Inorganic-Organic Hybrid Perovskites and Functionalized Metal-Oxide Nanosheets.” 2017. Doctoral Dissertation, University of New Orleans. Accessed January 16, 2021.
https://scholarworks.uno.edu/td/2287.
MLA Handbook (7th Edition):
Akbarian-Tefaghi, Sara. “Microwave-Assisted Topochemical Manipulation of Layered Oxide Perovskites: From Inorganic Layered Oxides to Inorganic-Organic Hybrid Perovskites and Functionalized Metal-Oxide Nanosheets.” 2017. Web. 16 Jan 2021.
Vancouver:
Akbarian-Tefaghi S. Microwave-Assisted Topochemical Manipulation of Layered Oxide Perovskites: From Inorganic Layered Oxides to Inorganic-Organic Hybrid Perovskites and Functionalized Metal-Oxide Nanosheets. [Internet] [Doctoral dissertation]. University of New Orleans; 2017. [cited 2021 Jan 16].
Available from: https://scholarworks.uno.edu/td/2287.
Council of Science Editors:
Akbarian-Tefaghi S. Microwave-Assisted Topochemical Manipulation of Layered Oxide Perovskites: From Inorganic Layered Oxides to Inorganic-Organic Hybrid Perovskites and Functionalized Metal-Oxide Nanosheets. [Doctoral Dissertation]. University of New Orleans; 2017. Available from: https://scholarworks.uno.edu/td/2287
.