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Università della Svizzera italiana
1.
Mattavelli, Andrea.
Software redundancy: what, where, how.
Degree: 2016, Università della Svizzera italiana
URL: http://doc.rero.ch/record/278320 
► Software systems have become pervasive in everyday life and are the core component of many crucial activities. An inadequate level of reliability may determine the…
(more)
▼ Software systems have become pervasive in everyday
life and are the core component of many crucial activities. An
inadequate level of reliability may determine the commercial
failure of a software product. Still, despite the commitment and
the rigorous verification processes employed by developers,
software is deployed with faults. To increase the reliability of
software systems, researchers have investigated the use of various
form of redundancy. Informally, a software system is redundant when
it performs the same functionality through the execution of
different elements. Redundancy has been extensively exploited in
many software engineering techniques, for example for
fault-tolerance and reliability engineering, and in
self-adaptive
and
self-
healing programs. Despite the many uses, though, there is
no formalization or study of software redundancy to support a
proper and effective design of software. Our intuition is that a
systematic and formal investigation of software redundancy will
lead to more, and more effective uses of redundancy. This thesis
develops this intuition and proposes a set of ways to characterize
qualitatively as well as quantitatively redundancy. We first
formalize the intuitive notion of redundancy whereby two code
fragments are considered redundant when they perform the same
functionality through different executions. On the basis of this
abstract and general notion, we then develop a practical method to
obtain a measure of software redundancy. We prove the effectiveness
of our measure by showing that it distinguishes between shallow
differences, where apparently different code fragments reduce to
the same underlying code, and deep code differences, where the
algorithmic nature of the computations differs. We also demonstrate
that our measure is useful for developers, since it is a good
predictor of the effectiveness of techniques that exploit
redundancy. Besides formalizing the notion of redundancy, we
investigate the pervasiveness of redundancy intrinsically found in
modern software systems. Intrinsic redundancy is a form of
redundancy that occurs as a by-product of modern design and
development practices. We have observed that intrinsic redundancy
is indeed present in software systems, and that it can be
successfully exploited for good purposes. This thesis proposes a
technique to automatically identify equivalent method sequences in
software systems to help developers assess the presence of
intrinsic redundancy. We demonstrate the effectiveness of the
technique by showing that it identifies the majority of equivalent
method sequences in a system with good precision and
performance.
Advisors/Committee Members: Mauro (Dir.), Antonio (Codir.).
Subjects/Keywords: Self-healing
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APA (6th Edition):
Mattavelli, A. (2016). Software redundancy: what, where, how. (Thesis). Università della Svizzera italiana. Retrieved from http://doc.rero.ch/record/278320
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):
Mattavelli, Andrea. “Software redundancy: what, where, how.” 2016. Thesis, Università della Svizzera italiana. Accessed October 17, 2019.
http://doc.rero.ch/record/278320.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Mattavelli, Andrea. “Software redundancy: what, where, how.” 2016. Web. 17 Oct 2019.
Vancouver:
Mattavelli A. Software redundancy: what, where, how. [Internet] [Thesis]. Università della Svizzera italiana; 2016. [cited 2019 Oct 17].
Available from: http://doc.rero.ch/record/278320.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Mattavelli A. Software redundancy: what, where, how. [Thesis]. Università della Svizzera italiana; 2016. Available from: http://doc.rero.ch/record/278320
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Waikato
2.
Membery, Brent.
Behind the Ink NZ: Tattoos in Aotearoa New Zealand and the Link to a Process of Self-Healing
.
Degree: 2015, University of Waikato
URL: http://hdl.handle.net/10289/10100
► This study aimed to examine the reasons why individuals in Aotearoa New Zealand tattoo their bodies and analyse the mechanism by which tattoo acts as…
(more)
▼ This study aimed to examine the reasons why individuals in Aotearoa New Zealand tattoo their bodies and analyse the mechanism by which tattoo acts as a method of coping,
self-
healing and
self-transformation for these individuals. Further this study aimed to investigate how tattoo allows individuals to re-write and transform their meaning of traumatic and/or stressful events into stories of empowerment, strength and survival. While tattoo has been explored for meaning and function in Aotearoa New Zealand, there was seen to be no empirically grounded research looking into how tattoo might serve as a therapeutic tool.
The study examined 427 survey respondents and eight interviewees across Aotearoa New Zealand. The participants ranged in age from 18 to 65-years-old and varied across multiple ethnicities.
This study combined quantitative and qualitative data collection methods in a two-phase project. Data collection phase one involved 427 participants respond to an online survey. This establised a baseline for cross-comparison of attitudes, backgrounds and life experiences. Data collection phase two involved eight semi-structured interviews to explore individual experiences and uncover the relationship between their tattoos and how it had helped them to cope/heal in some way. To analyse these interviews, thematic analysis was combined with phenomenological analysis.
The findings from this study suggest that there are multiple reasons (expression of
self, aesthetic aspects, identity, passage of rights, remembrance/tributes and personal
healing among others) why individuals chose to engage in the art form of tattooing. Findings also suggest that tattoo, directly relating to the mind/body continuum of stress/trauma can serve as a mechanism to enable individuals to re-script stressful/traumatic events, reinforce identity and
self-acceptance, acknowledge past difficulties and turn them into positives and increase inner motivations and positive thinking which was seen to initiate
healing and recovery. This suggests that tattoo serves as a powerful mechanism to aid in personal transformation, but also challenge previous meanings associated with the art form of tattoo.
Advisors/Committee Members: Thakker, Jo (advisor).
Subjects/Keywords: Tattoos;
Self-healing;
Self-transformation
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APA (6th Edition):
Membery, B. (2015). Behind the Ink NZ: Tattoos in Aotearoa New Zealand and the Link to a Process of Self-Healing
. (Masters Thesis). University of Waikato. Retrieved from http://hdl.handle.net/10289/10100
Chicago Manual of Style (16th Edition):
Membery, Brent. “Behind the Ink NZ: Tattoos in Aotearoa New Zealand and the Link to a Process of Self-Healing
.” 2015. Masters Thesis, University of Waikato. Accessed October 17, 2019.
http://hdl.handle.net/10289/10100.
MLA Handbook (7th Edition):
Membery, Brent. “Behind the Ink NZ: Tattoos in Aotearoa New Zealand and the Link to a Process of Self-Healing
.” 2015. Web. 17 Oct 2019.
Vancouver:
Membery B. Behind the Ink NZ: Tattoos in Aotearoa New Zealand and the Link to a Process of Self-Healing
. [Internet] [Masters thesis]. University of Waikato; 2015. [cited 2019 Oct 17].
Available from: http://hdl.handle.net/10289/10100.
Council of Science Editors:
Membery B. Behind the Ink NZ: Tattoos in Aotearoa New Zealand and the Link to a Process of Self-Healing
. [Masters Thesis]. University of Waikato; 2015. Available from: http://hdl.handle.net/10289/10100
Louisiana State University
3.
Yougoubare, Yves Quentin.
Programming and healing temperature effects on the efficiency of confined self-healing polymers.
Degree: MSME, Mechanical Engineering, 2012, Louisiana State University
URL: etd-11132012-132152
;
https://digitalcommons.lsu.edu/gradschool_theses/4231
► Shape memory polymers are smart materials capable of fixing a temporary shape and returning to their initial shape in response to an external stimulus. Since…
(more)
▼ Shape memory polymers are smart materials capable of fixing a temporary shape and returning to their initial shape in response to an external stimulus. Since the discovery and acknowledgment of their importance in 1960s, shape memory polymers have been the subject of tremendous and continuous attention. In a previous study conducted on a biomimetic shape memory polymer (SMP), the ability of a self-healing composite to heal, and to repair and restore structural-length scale damage using a close-then-heal (CTH) self-healing mechanism was examined and validated. The present study is purposed with investigation of the effects on healing efficiencies of the variation of temperature during both thermo-mechanical programming and shape recovery under three-dimensional (3-D) confinement. The polymer considered was a polystyrene shape memory polymer with 6% by volume of thermoplastic particle additives (copolyester) dispersed in the matrix. After fabrication, and determination of their glass transition temperature using DSC, the specimens were allowed to go through a strain-controlled programming at a wide range of temperatures (20°C, 45°C, 60°C, 82°C, 100°C and 140°C), at a pre-strain level of 15%. Fracture was imposed using a three-point flexure apparatus, and was followed by shape recovery at multiple temperatures (73°C, 100°C, 122°C and 148°C). The self-healing efficiency was evaluated per flexural strength immediately after programming and following healing. The results and deductions attained were verified using EDS analysis and SEM inspection. It is inferred from the study that the programming temperature only very slightly affects the recovered strength. Programming the specimen above its glass transition temperature provided a marginal gain in strength recovery. Shape recovery (healing) temperature, however, was found to have a significant impact on the self-healing efficiency. A sudden “boost” was noted around the melting temperature of the thermoplastics, with a significant increase in the healing efficiency past the bonding temperature of the copolymer. It was observed that programming above the glass transition temperature of the composite and healing above the melting point of the thermoplastic addives ensured a maximum healing efficiency of up to 63% for the material considered.
Subjects/Keywords: programming; healing; self-healing; biomimetic; temperature; polymer
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APA (6th Edition):
Yougoubare, Y. Q. (2012). Programming and healing temperature effects on the efficiency of confined self-healing polymers. (Masters Thesis). Louisiana State University. Retrieved from etd-11132012-132152 ; https://digitalcommons.lsu.edu/gradschool_theses/4231
Chicago Manual of Style (16th Edition):
Yougoubare, Yves Quentin. “Programming and healing temperature effects on the efficiency of confined self-healing polymers.” 2012. Masters Thesis, Louisiana State University. Accessed October 17, 2019.
etd-11132012-132152 ; https://digitalcommons.lsu.edu/gradschool_theses/4231.
MLA Handbook (7th Edition):
Yougoubare, Yves Quentin. “Programming and healing temperature effects on the efficiency of confined self-healing polymers.” 2012. Web. 17 Oct 2019.
Vancouver:
Yougoubare YQ. Programming and healing temperature effects on the efficiency of confined self-healing polymers. [Internet] [Masters thesis]. Louisiana State University; 2012. [cited 2019 Oct 17].
Available from: etd-11132012-132152 ; https://digitalcommons.lsu.edu/gradschool_theses/4231.
Council of Science Editors:
Yougoubare YQ. Programming and healing temperature effects on the efficiency of confined self-healing polymers. [Masters Thesis]. Louisiana State University; 2012. Available from: etd-11132012-132152 ; https://digitalcommons.lsu.edu/gradschool_theses/4231
Louisiana State University
4.
Gilford III, James.
Microencapsulation of self-healing concrete properties.
Degree: MSES, Construction Engineering and Management, 2012, Louisiana State University
URL: etd-07052012-110306
;
https://digitalcommons.lsu.edu/gradschool_theses/194
► ABSTRACT Recent studies in the literature have demonstrated the ability of self-healing processes to be effective in enhancing the overall life of concrete. The main…
(more)
▼ ABSTRACT Recent studies in the literature have demonstrated the ability of self-healing processes to be effective in enhancing the overall life of concrete. The main goal of this project is to evaluate and to control specific parameters for the production of an effective self-healing matrix that can be utilized within the application of self-healing concrete. Therefore, the project objective is to synthesize microcapsules using dicyclopentadine and sodium silicate and to evaluate the effects of pH, temperature, and agitation rate on microcapsule morphology. The microcapsule diameter, yield analysis, and shell thickness were characterized using scanning electron microscopy. During the experimental analysis, it was determined that temperature possesses a direct relationship with the pH for both sodium silicate and DCDP. As the temperature increased during the trials, the pH decreased. Temperature had a direct impact on the forming of the wall and core during the interfacial polymerization phase. Although the ability to maintain this consistency with the pH is important and essential, agitation rate is the key factor that controls the microcapsule capsule diameter size. As the agitation rate is increased, the microcapsule diameter size will decrease. If the agitation rate decreases, the microcapsules will become larger. Sodium silicate, however, was not consistent with the normal parameter matrix, due to its alkaline nature. As the agitation rate increased, the size remained normal and consistent. This was due to the attempt to stabilize the sodium silicate solution for the micro-encapsulation procedure of Urea-Formaldehyde. Nevertheless, both sodium silicate and DCDP trials were successful in meeting the overall objective of this thesis, which was to control the performance parameters of the two self-healing methods.
Subjects/Keywords: Self-Healing Concrete; Techniques
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APA ·
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MLA ·
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Export
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Manager
APA (6th Edition):
Gilford III, J. (2012). Microencapsulation of self-healing concrete properties. (Masters Thesis). Louisiana State University. Retrieved from etd-07052012-110306 ; https://digitalcommons.lsu.edu/gradschool_theses/194
Chicago Manual of Style (16th Edition):
Gilford III, James. “Microencapsulation of self-healing concrete properties.” 2012. Masters Thesis, Louisiana State University. Accessed October 17, 2019.
etd-07052012-110306 ; https://digitalcommons.lsu.edu/gradschool_theses/194.
MLA Handbook (7th Edition):
Gilford III, James. “Microencapsulation of self-healing concrete properties.” 2012. Web. 17 Oct 2019.
Vancouver:
Gilford III J. Microencapsulation of self-healing concrete properties. [Internet] [Masters thesis]. Louisiana State University; 2012. [cited 2019 Oct 17].
Available from: etd-07052012-110306 ; https://digitalcommons.lsu.edu/gradschool_theses/194.
Council of Science Editors:
Gilford III J. Microencapsulation of self-healing concrete properties. [Masters Thesis]. Louisiana State University; 2012. Available from: etd-07052012-110306 ; https://digitalcommons.lsu.edu/gradschool_theses/194
University of Cambridge
5.
Ribeiro de Souza, Lívia.
Design and synthesis of microcapsules using microfluidics for autonomic self-healing in cementitious materials.
Degree: PhD, 2017, University of Cambridge
URL: https://www.repository.cam.ac.uk/handle/1810/269746
;
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.744322
► A capsule-based self-healing cementitious material, capable of autonomically repairing its own cracks, can extend the service life of concrete structures and decrease the costs associate…
(more)
▼ A capsule-based self-healing cementitious material, capable of autonomically repairing its own cracks, can extend the service life of concrete structures and decrease the costs associate with repair and maintenance actions. However, the size, shell thickness, shell material and mechanical properties of the capsules still need to be optimised to ensure self-healing performance. Thus, the objective of this research was to explore the controlled microfluidic encapsulation to investigate the production of microcapsules for physically triggered self-healing in cementitious materials. A flow-focusing microfluidic device was used to produce double emulsions to be selectively photopolymerised to generate a core-shell structure. Subsequently, the physical triggering was assessed by embedding the produced microcapsules in cement paste, fracturing it and observing the cracked surface in the SEM. The results showed the production of microcapsules with 80-140 μm of diameter with excellent control over size and shell thickness. Using water-in-oil-in-water (w/o/w) double emulsion, microcapsules were synthesised containing water, colloidal silica solution and sodium silicate solution as core material. In addition, an oil-in-oil-in-water (o/o/w) double emulsion was used to encapsulate mineral oil and emulsified healing agents. The formation of the core-shell structure with aqueous and organic cores was characterised using optical microscopy and SEM. It was demonstrated that the water is not retained inside of the capsule, resulting in the formation of dimples and buckled capsules, particularly for shells thickness ~7 μm. On the other hand, TGA confirmed the retention of mineral oil for shells thickness of ~2 μm and the encapsulation efficiency was demonstrated to be 66%. When the capsules were added to the cement paste, four key factors were observed to prevent physical triggering: (i) thick shells, (ii) buckling of thinner shells due to the loss of water core, (iii) mechanical properties and (iv) poor interfacial bonding. As a result, a mechanical characterisation of the shell material was performed, indicating brittle fracture at room temperature, reduced Young’s modulus when compared with cementitious matrix and stress at rupture of 15-36 MPa. In addition, an innovative methodology was proposed to functionalise the surface of the microcapsules with hydrophilic groups in order to increase the interfacial bonding between the cement paste and the microcapsules. Thus, microcapsules with low tensile strength, low shell thickness, organic core and good interfacial bonding were successfully synthesised and demonstrated to rupture upon crack formation. These results experimentally demonstrate the importance of reduced shell thickness, core retention and interfacial bonding as valuable guides during the design of microcapsules for physically triggered self-healing in cementitious materials.
Subjects/Keywords: self-healing; microfluidics; microcapsules
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Record Details
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Ribeiro de Souza, L. (2017). Design and synthesis of microcapsules using microfluidics for autonomic self-healing in cementitious materials. (Doctoral Dissertation). University of Cambridge. Retrieved from https://www.repository.cam.ac.uk/handle/1810/269746 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.744322
Chicago Manual of Style (16th Edition):
Ribeiro de Souza, Lívia. “Design and synthesis of microcapsules using microfluidics for autonomic self-healing in cementitious materials.” 2017. Doctoral Dissertation, University of Cambridge. Accessed October 17, 2019.
https://www.repository.cam.ac.uk/handle/1810/269746 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.744322.
MLA Handbook (7th Edition):
Ribeiro de Souza, Lívia. “Design and synthesis of microcapsules using microfluidics for autonomic self-healing in cementitious materials.” 2017. Web. 17 Oct 2019.
Vancouver:
Ribeiro de Souza L. Design and synthesis of microcapsules using microfluidics for autonomic self-healing in cementitious materials. [Internet] [Doctoral dissertation]. University of Cambridge; 2017. [cited 2019 Oct 17].
Available from: https://www.repository.cam.ac.uk/handle/1810/269746 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.744322.
Council of Science Editors:
Ribeiro de Souza L. Design and synthesis of microcapsules using microfluidics for autonomic self-healing in cementitious materials. [Doctoral Dissertation]. University of Cambridge; 2017. Available from: https://www.repository.cam.ac.uk/handle/1810/269746 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.744322
University of Cambridge
6.
Ribeiro de Souza, Lívia.
Design and synthesis of microcapsules using microfluidics for autonomic self-healing in cementitious materials
.
Degree: 2017, University of Cambridge
URL: https://www.repository.cam.ac.uk/handle/1810/269746
► A capsule-based self-healing cementitious material, capable of autonomically repairing its own cracks, can extend the service life of concrete structures and decrease the costs associate…
(more)
▼ A capsule-based self-healing cementitious material, capable of autonomically repairing its own cracks, can extend the service life of concrete structures and decrease the costs associate with repair and maintenance actions. However, the size, shell thickness, shell material and mechanical properties of the capsules still need to be optimised to ensure self-healing performance. Thus, the objective of this research was to explore the controlled microfluidic encapsulation to investigate the production of microcapsules for physically triggered self-healing in cementitious materials. A flow-focusing microfluidic device was used to produce double emulsions to be selectively photopolymerised to generate a core-shell structure. Subsequently, the physical triggering was assessed by embedding the produced microcapsules in cement paste, fracturing it and observing the cracked surface in the SEM. The results showed the production of microcapsules with 80-140 μm of diameter with excellent control over size and shell thickness. Using water-in-oil-in-water (w/o/w) double emulsion, microcapsules were synthesised containing water, colloidal silica solution and sodium silicate solution as core material. In addition, an oil-in-oil-in-water (o/o/w) double emulsion was used to encapsulate mineral oil and emulsified healing agents. The formation of the core-shell structure with aqueous and organic cores was characterised using optical microscopy and SEM. It was demonstrated that the water is not retained inside of the capsule, resulting in the formation of dimples and buckled capsules, particularly for shells thickness ~7 μm. On the other hand, TGA confirmed the retention of mineral oil for shells thickness of ~2 μm and the encapsulation efficiency was demonstrated to be 66%. When the capsules were added to the cement paste, four key factors were observed to prevent physical triggering: (i) thick shells, (ii) buckling of thinner shells due to the loss of water core, (iii) mechanical properties and (iv) poor interfacial bonding. As a result, a mechanical characterisation of the shell material was performed, indicating brittle fracture at room temperature, reduced Young’s modulus when compared with cementitious matrix and stress at rupture of 15-36 MPa. In addition, an innovative methodology was proposed to functionalise the surface of the microcapsules with hydrophilic groups in order to increase the interfacial bonding between the cement paste and the microcapsules. Thus, microcapsules with low tensile strength, low shell thickness, organic core and good interfacial bonding were successfully synthesised and demonstrated to rupture upon crack formation. These results experimentally demonstrate the importance of reduced shell thickness, core retention and interfacial bonding as valuable guides during the design of microcapsules for physically triggered self-healing in cementitious materials.
Subjects/Keywords: self-healing;
microfluidics;
microcapsules
Record Details
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Record Details
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Ribeiro de Souza, L. (2017). Design and synthesis of microcapsules using microfluidics for autonomic self-healing in cementitious materials
. (Thesis). University of Cambridge. Retrieved from https://www.repository.cam.ac.uk/handle/1810/269746
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):
Ribeiro de Souza, Lívia. “Design and synthesis of microcapsules using microfluidics for autonomic self-healing in cementitious materials
.” 2017. Thesis, University of Cambridge. Accessed October 17, 2019.
https://www.repository.cam.ac.uk/handle/1810/269746.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Ribeiro de Souza, Lívia. “Design and synthesis of microcapsules using microfluidics for autonomic self-healing in cementitious materials
.” 2017. Web. 17 Oct 2019.
Vancouver:
Ribeiro de Souza L. Design and synthesis of microcapsules using microfluidics for autonomic self-healing in cementitious materials
. [Internet] [Thesis]. University of Cambridge; 2017. [cited 2019 Oct 17].
Available from: https://www.repository.cam.ac.uk/handle/1810/269746.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Ribeiro de Souza L. Design and synthesis of microcapsules using microfluidics for autonomic self-healing in cementitious materials
. [Thesis]. University of Cambridge; 2017. Available from: https://www.repository.cam.ac.uk/handle/1810/269746
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Miami
7.
Wehbe, Yara.
Bio-Inspired Self-Healing Infrastructure Materials.
Degree: MS, Civil, Architectural and Environmental Engineering (Engineering), 2016, University of Miami
URL: https://scholarlyrepository.miami.edu/oa_theses/619
► The current state of our nation’s infrastructure was given a grade of D+ in 2013, which warrants immediate remedial actions to improve structural integrity…
(more)
▼ The current state of our nation’s infrastructure was given a grade of D+ in 2013, which warrants immediate remedial actions to improve structural integrity and ensure public safety. This has motivated intensive research aimed at enhancing the sustainability of infrastructure with the goal of reducing maintenance cost. Concrete is the most widely used infrastructure materials primarily due to its low cost and wide applicability. However, concrete is brittle and prone to crack formation due to mechanical loads and environmental conditions during its service life. Thus, innovative materials with
self-
healing capability provide a viable path towards mitigating crack related issues facing concrete infrastructure. In this dissertation, an overview of a bio-inspired
self-
healing methodology is presented. This methodology is based on microorganism induced calcium carbonate (CaCO
3) precipitation filling and binding cracks in the cementitious materials. The effect of addition of microorganisms and related materials on the hydration, compressive strength, transport, and microstructure of cementitious materials is evaluated. The influence of parameters affecting the morphology and chemical structure of CaCO
3 is investigated, using microscopy and analytical techniques, to establish the process-microstructure relations of CaCO
3.
Advisors/Committee Members: Ali Ghahremaninezhad, Landolf Rhode Barbarigos, Claudio Mazzotti.
Subjects/Keywords: Microorganisms; self-healing; concrete
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MLA ·
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Manager
APA (6th Edition):
Wehbe, Y. (2016). Bio-Inspired Self-Healing Infrastructure Materials. (Thesis). University of Miami. Retrieved from https://scholarlyrepository.miami.edu/oa_theses/619
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):
Wehbe, Yara. “Bio-Inspired Self-Healing Infrastructure Materials.” 2016. Thesis, University of Miami. Accessed October 17, 2019.
https://scholarlyrepository.miami.edu/oa_theses/619.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Wehbe, Yara. “Bio-Inspired Self-Healing Infrastructure Materials.” 2016. Web. 17 Oct 2019.
Vancouver:
Wehbe Y. Bio-Inspired Self-Healing Infrastructure Materials. [Internet] [Thesis]. University of Miami; 2016. [cited 2019 Oct 17].
Available from: https://scholarlyrepository.miami.edu/oa_theses/619.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Wehbe Y. Bio-Inspired Self-Healing Infrastructure Materials. [Thesis]. University of Miami; 2016. Available from: https://scholarlyrepository.miami.edu/oa_theses/619
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Illinois – Urbana-Champaign
8.
Jones, Amanda Rose.
Solvent-based self-healing approaches for fiber-reinforced composites.
Degree: PhD, Theoretical & Applied Mechans, 2015, University of Illinois – Urbana-Champaign
URL: http://hdl.handle.net/2142/78389
► Damage in composite materials spans many length scales and is often difficult to detect or costly to repair. The incorporation of self-healing functionality in composite…
(more)
▼ Damage in composite materials spans many length scales and is often difficult to detect or costly to repair. The incorporation of
self-
healing functionality in composite materials has the potential to greatly extend material lifetime and reliability. Although there has been remarkable progress in
self-
healing polymers over the the past decade,
self-repair in fiber-reinforced composite materials presents significant technical challenges due to stringent manufacturing and performance requirements. For high performance, fiber-reinforced composites, the
self-
healing components need to survive high temperature processing, reside in matrix interstitial regions to retain a high fiber volume fraction, and have minimal impact on the mechanical properties of the host material. This dissertation explores several microencapsulated solvent-based
self-
healing approaches for fiber-reinforced composites at the fiber/ matrix interface size scale as well as matrix cracking. Systems are initially developed for room temperature cured epoxies/ glass fiber interfaces and successfully transitioned to carbon fibers and high temperature-cured, thermoplastic-toughened matrices.
Full recovery of interfacial bond strength after complete fiber/matrix debonding is achieved with a microencapsulated solvent-based
healing chemistry. The surface of a glass fiber is functionalized with microcapsules containing varying concentrations of reactive epoxy resin and ethyl phenyl acetate (EPA) solvent. Microbond specimens consisting of a single fiber and a microdroplet of epoxy are cured at 35C, tested, and the interfacial shear strengths (IFSS) during the initial (virgin) debonding and subsequent
healing events are measured. Debonding of the fiber/matrix interface ruptures the capsules, releasing resin and solvent into the crack plane. The solvent swells the matrix, initiating transport of residual amine functionality for further curing with the epoxy resin delivered to the crack plane. Using a resin-solvent ratio of 3:97, a maximum of 100% IFSS recovery is achieved – a significant enhancement over prior work that reported 44% average recovery of IFSS with microencapsulated dicyclopentadiene (DCPD) monomer and Grubbs' 1st Generation catalyst
healing agents. The effects of capsule coverage, resin-solvent ratio, and capsule size on recovery of IFSS are also determined, providing guidelines for integration of this
healing system into high fiber volume fraction structural composites. High
healing efficiencies are achieved with capsules as small as 0.6 µm average diameter.
The resin-solvent
healing system is then extended to repair of a carbon fiber/epoxy interfacial bond. A binder is necessary to improve the retention of capsules on the carbon fiber surface. Two different methods for applying a binder to a carbon fiber surface are investigated.
Healing efficiency is assessed by recovery of IFSS of a single functionalized fiber embedded in an epoxy microbond specimen. The two binder protocols produce comparable results, both…
Advisors/Committee Members: Sottos, Nancy R. (advisor), Sottos, Nancy R. (Committee Chair), White, Scott R. (committee member), Geubelle, Philippe H. (committee member), Ewoldt, Randy H. (committee member).
Subjects/Keywords: self-healing; polymer matrix composites
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APA (6th Edition):
Jones, A. R. (2015). Solvent-based self-healing approaches for fiber-reinforced composites. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/78389
Chicago Manual of Style (16th Edition):
Jones, Amanda Rose. “Solvent-based self-healing approaches for fiber-reinforced composites.” 2015. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed October 17, 2019.
http://hdl.handle.net/2142/78389.
MLA Handbook (7th Edition):
Jones, Amanda Rose. “Solvent-based self-healing approaches for fiber-reinforced composites.” 2015. Web. 17 Oct 2019.
Vancouver:
Jones AR. Solvent-based self-healing approaches for fiber-reinforced composites. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2015. [cited 2019 Oct 17].
Available from: http://hdl.handle.net/2142/78389.
Council of Science Editors:
Jones AR. Solvent-based self-healing approaches for fiber-reinforced composites. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2015. Available from: http://hdl.handle.net/2142/78389
University of Illinois – Urbana-Champaign
9.
Gergely, Ryan C.
Regeneration of impact puncture and abrasive damage in polymers.
Degree: PhD, Theoretical & Applied Mechans, 2016, University of Illinois – Urbana-Champaign
URL: http://hdl.handle.net/2142/92999
► Engineering materials experience damage during their lifetime, which reduces their ability to carry load and maintain structural integrity. Self-healing materials have been developed to mitigate…
(more)
▼ Engineering materials experience damage during their lifetime, which reduces their ability to carry load and maintain structural integrity.
Self-
healing materials have been developed to mitigate the effects of damage, however, there are currently limitations in the healable length scale of damage that can be addressed. Overcoming this challenge requires a shift from simply re-bonding of cracks, which describes many current
self-
healing systems. Features of biological regeneration can be used to inspire approaches to address larger length scales of damage and achieve repeatable replacement of damaged or lost material. This thesis focuses on development of strategies for synthetic regeneration in polymers.
Concepts inspired by biological regeneration are applied to the problem of restoration of lost (damage) volume. Two specific damage modes that result in volumetric material loss are considered: impact puncture damage, and abrasive removal of a coating. This thesis focuses on demonstrating regeneration in response to these damage modes, and establishes experimental protocols for evaluation of performance. In addition, advancements are made in the fabrication of microvascular polymeric materials.
The transverse impact of plates of vascularized transparent polymer results in a multiscale damage pattern in which a centimeter-scale central puncture of lost (damage) volume is opened up where the projectile is incident, as well as a network of radiating microcracks emanating from the impact point. An embedded microvascular network facilitates the delivery of a novel two-stage
healing agent to the site of damage in order to restore the lost damage volume. The performance of the restored specimens is evaluated by both seal testing under pressurization and impact energy absorption under repeat impact testing. Factors affecting the impact restoration performance are explored. The formulation of the two-stage
healing agents is modulated to improve impact energy absorption. Sealing of 100% of samples is achieved by a hybrid system incorporating both a vascular network and microcapsules to separately target large damage (central puncture) and small microcracks.
Abrasive damage can result in complete removal of a protective coating and exposure of the underlying substrate. To regenerate the coating after damage, a single-part
healing agent is released upon removal of the coating, and cures when exposed to simulated ambient sunlight. The regenerated coating is evaluated by hardness testing. Coating regeneration is facilitated by a pressurized microvascular system containing a compliant protective (UV blocking) valve. The polymeric coating is regenerated with the same hardness after large-scale removal, for four repetitive damage events (abrasion).
To improve control of the volume of
healing agent released in response to damage, an accumulator is developed for incorporation into microvascular coating systems. The accumulator enables the localized storage of a prescribed volume of
healing agent. Upon damage, this stored volume…
Advisors/Committee Members: White, Scott R (advisor), Sottos, Nancy R (Committee Chair), Freund, Jonathan B (committee member), Ewoldt, Randy H (committee member).
Subjects/Keywords: Polymers; Self-Healing; Regeneration; Microvascular
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APA (6th Edition):
Gergely, R. C. (2016). Regeneration of impact puncture and abrasive damage in polymers. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/92999
Chicago Manual of Style (16th Edition):
Gergely, Ryan C. “Regeneration of impact puncture and abrasive damage in polymers.” 2016. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed October 17, 2019.
http://hdl.handle.net/2142/92999.
MLA Handbook (7th Edition):
Gergely, Ryan C. “Regeneration of impact puncture and abrasive damage in polymers.” 2016. Web. 17 Oct 2019.
Vancouver:
Gergely RC. Regeneration of impact puncture and abrasive damage in polymers. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2016. [cited 2019 Oct 17].
Available from: http://hdl.handle.net/2142/92999.
Council of Science Editors:
Gergely RC. Regeneration of impact puncture and abrasive damage in polymers. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2016. Available from: http://hdl.handle.net/2142/92999
University of Illinois – Urbana-Champaign
10.
Hart, Kevin Richard.
Self-healing of impact damage in vascular fiber-reinforced composites.
Degree: PhD, Aerospace Engineering, 2016, University of Illinois – Urbana-Champaign
URL: http://hdl.handle.net/2142/90721
► Vascular fiber-reinforced composites mimic biological systems to allow pluripotent multifunctional behavior in synthetic engineering materials. In this dissertation, methods are explored for recovering mechanical performance…
(more)
▼ Vascular fiber-reinforced composites mimic biological systems to allow pluripotent multifunctional behavior in synthetic engineering materials. In this dissertation, methods are explored for recovering mechanical performance of a composite material after an out-of-plane impact event using vascular
self-
healing technologies. To date, the critical damage modes which occur during out-of-plane impact that most significantly contribute to reductions in post-impact performance have not been identified and methods for delivering
healing agents to those critical regions using internal vascular networks has not been explored. In this dissertation, out-of-plane impact damage is quantified and correlated with reductions in post-impact mechanical performance. Additionally,
healing of impact-induced damage is demonstrated using vascular delivery of epoxy and amine based agents. An alternate
healing agent chemistry for potential use in vascular
healing schemes is also discussed. This work is the first to detail methods for
healing impact-induced damage in vascular composites using segregated
healing agent components and paves the way for the adoption of
self-
healing vascular materials in commercial applications.
Advisors/Committee Members: White, Scott (advisor), White, Scott (Committee Chair), Sottos, Nancy (committee member), Geubelle, Philippe H. (committee member), Lambros, John (committee member).
Subjects/Keywords: Self-Healing; Vascular; Composites
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APA (6th Edition):
Hart, K. R. (2016). Self-healing of impact damage in vascular fiber-reinforced composites. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/90721
Chicago Manual of Style (16th Edition):
Hart, Kevin Richard. “Self-healing of impact damage in vascular fiber-reinforced composites.” 2016. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed October 17, 2019.
http://hdl.handle.net/2142/90721.
MLA Handbook (7th Edition):
Hart, Kevin Richard. “Self-healing of impact damage in vascular fiber-reinforced composites.” 2016. Web. 17 Oct 2019.
Vancouver:
Hart KR. Self-healing of impact damage in vascular fiber-reinforced composites. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2016. [cited 2019 Oct 17].
Available from: http://hdl.handle.net/2142/90721.
Council of Science Editors:
Hart KR. Self-healing of impact damage in vascular fiber-reinforced composites. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2016. Available from: http://hdl.handle.net/2142/90721
University of Manitoba
11.
Yu, Lianlian Jr.
Cell-compatible multi-functional crosslinker-based hydrogels for tissue engineering.
Degree: Textile Sciences, 2015, University of Manitoba
URL: http://hdl.handle.net/1993/30180
► The thesis showed preliminary evaluation of novel biodegradable and biocompatible agmatine-containing PAA crosslinkers. Hydrogels fabricated by this crosslinker can obtain controllable stiffness and excellent cell…
(more)
▼ The thesis showed preliminary evaluation of novel biodegradable and biocompatible agmatine-containing PAA crosslinkers. Hydrogels fabricated by this crosslinker can obtain controllable stiffness and excellent cell adhesion. The PAA contained thermo-sensitive hydrogel reported here is first employed as filler for depressed defects in rats. Results showed that such hydrogel can be injectable and biocompatible, might become a new material in plastic surgery in the clinic. The thesis also demonstrated a novel macro gels with
self-
healing capability and biocompatibility. The reversible photodimerization and photocleavage reactivity of coumarin has been successfully imparted to the polymer.
Advisors/Committee Members: Zhong, Wen (Textile Sciences) Xing, Malcolm (Mechanical Engineering) (supervisor), Wang, Quan (Mechanical Engineering) Cai, Jun (Electrical and Computer Engineering) (examiningcommittee).
Subjects/Keywords: biocompatible; self-healing; hydrogel; crosslinker
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APA (6th Edition):
Yu, L. J. (2015). Cell-compatible multi-functional crosslinker-based hydrogels for tissue engineering. (Masters Thesis). University of Manitoba. Retrieved from http://hdl.handle.net/1993/30180
Chicago Manual of Style (16th Edition):
Yu, Lianlian Jr. “Cell-compatible multi-functional crosslinker-based hydrogels for tissue engineering.” 2015. Masters Thesis, University of Manitoba. Accessed October 17, 2019.
http://hdl.handle.net/1993/30180.
MLA Handbook (7th Edition):
Yu, Lianlian Jr. “Cell-compatible multi-functional crosslinker-based hydrogels for tissue engineering.” 2015. Web. 17 Oct 2019.
Vancouver:
Yu LJ. Cell-compatible multi-functional crosslinker-based hydrogels for tissue engineering. [Internet] [Masters thesis]. University of Manitoba; 2015. [cited 2019 Oct 17].
Available from: http://hdl.handle.net/1993/30180.
Council of Science Editors:
Yu LJ. Cell-compatible multi-functional crosslinker-based hydrogels for tissue engineering. [Masters Thesis]. University of Manitoba; 2015. Available from: http://hdl.handle.net/1993/30180
Rochester Institute of Technology
12.
Rahman, Faiz Ur.
Resiliency in Deep Convolutional Neural Networks.
Degree: MS, Computer Engineering, 2018, Rochester Institute of Technology
URL: https://scholarworks.rit.edu/theses/9937
► The enormous success and popularity of deep convolutional neural networks for object detection has prompted their deployment in various real-world applications. However, their performance…
(more)
▼ The enormous success and popularity of deep convolutional neural networks for object detection has prompted their deployment in various real-world applications. However, their performance in the presence of hardware faults or damage that could occur in the field has not been studied. This thesis explores the resiliency of six popular network architectures for image classification, AlexNet, VGG16, ResNet, GoogleNet, SqueezeNet and YOLO9000, when subjected to various degrees of failures. We introduce failures in a deep network by dropping a percentage of weights at each layer. We then assess the effects of these failures on classification performance. We find the fitness of the weights and then dropped from least fit to most fit weights. Finally, we determine the ability of the network to
self-heal and recover its performance by retraining its healthy portions after partial damage. We try different methods to re-train the healthy portion by varying the optimizer. We also try to find the time and resources required for re-training. We also reduce the number of parameters in GoogleNet, VGG16 to the size of SqueezeNet and re-trained with varying percentage of dataset. This can be used as a network pruning method.
Advisors/Committee Members: Andreas Savakis, Andres Kwasinski, Dhireesha Kudithipudi.
Subjects/Keywords: DCNN; Resiliency; Self-healing
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APA (6th Edition):
Rahman, F. U. (2018). Resiliency in Deep Convolutional Neural Networks. (Masters Thesis). Rochester Institute of Technology. Retrieved from https://scholarworks.rit.edu/theses/9937
Chicago Manual of Style (16th Edition):
Rahman, Faiz Ur. “Resiliency in Deep Convolutional Neural Networks.” 2018. Masters Thesis, Rochester Institute of Technology. Accessed October 17, 2019.
https://scholarworks.rit.edu/theses/9937.
MLA Handbook (7th Edition):
Rahman, Faiz Ur. “Resiliency in Deep Convolutional Neural Networks.” 2018. Web. 17 Oct 2019.
Vancouver:
Rahman FU. Resiliency in Deep Convolutional Neural Networks. [Internet] [Masters thesis]. Rochester Institute of Technology; 2018. [cited 2019 Oct 17].
Available from: https://scholarworks.rit.edu/theses/9937.
Council of Science Editors:
Rahman FU. Resiliency in Deep Convolutional Neural Networks. [Masters Thesis]. Rochester Institute of Technology; 2018. Available from: https://scholarworks.rit.edu/theses/9937
Purdue University
13.
Johnston, Michael Laird.
A Bio-Inspired Self-Healing Polymer System for Sustainable Plastics.
Degree: PhD, Materials Engineering, 2015, Purdue University
URL: https://docs.lib.purdue.edu/open_access_dissertations/1304
► Studying how marine organisms make tough biologic materials that autonomously heal allows us to integrate this biological self-healing motif into synthetic biomimetic polymers. These types…
(more)
▼ Studying how marine organisms make tough biologic materials that autonomously heal allows us to integrate this biological
self-
healing motif into synthetic biomimetic polymers. These types of polymers will be used to develop components with greater fatigue life and toughness, promoting greater resource sustainability by reducing plastic consumption. The amino acid 3,4-dihydroxyphenylalanine (DOPA) grants marine mussels the ability to strongly affix themselves to the rocks under water by forming strong reversible bonds with their environment. Poly[(3,4-dihydroxystyrene)-co-styrene)] (P[3,4-DHS-S]) is a synthetic polymer mimic of DOPA with chemical structure similar to polystyrene (PS) with a potential
self-
healing mechanism. This intrinsic
self-
healing mechanism works to toughen and reform bonds to inhibit or retard crack propagation without external stimuli and energy. This work investigates the critical stress intensity for propagating preexisting cracks induced by a Vickers indentation in P[3,4-DHS-S], and the effects that different cross-linking agents have on crack growth within the polymer matrix. A Life Cycle Assessment (LCA) is also performed to give component designers supplemental information needed to evaluate any differences between using P[3,4-DHS-S] as an alternative to PS in terms of environmental and economic sustainability.
Advisors/Committee Members: John E. Blendell, Jonathan J. Wilker, Jeffrey P. Youngblood, Rodney W. Trice.
Subjects/Keywords: Fracture; Polymer; Self-Healing; Sustainability
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APA (6th Edition):
Johnston, M. L. (2015). A Bio-Inspired Self-Healing Polymer System for Sustainable Plastics. (Doctoral Dissertation). Purdue University. Retrieved from https://docs.lib.purdue.edu/open_access_dissertations/1304
Chicago Manual of Style (16th Edition):
Johnston, Michael Laird. “A Bio-Inspired Self-Healing Polymer System for Sustainable Plastics.” 2015. Doctoral Dissertation, Purdue University. Accessed October 17, 2019.
https://docs.lib.purdue.edu/open_access_dissertations/1304.
MLA Handbook (7th Edition):
Johnston, Michael Laird. “A Bio-Inspired Self-Healing Polymer System for Sustainable Plastics.” 2015. Web. 17 Oct 2019.
Vancouver:
Johnston ML. A Bio-Inspired Self-Healing Polymer System for Sustainable Plastics. [Internet] [Doctoral dissertation]. Purdue University; 2015. [cited 2019 Oct 17].
Available from: https://docs.lib.purdue.edu/open_access_dissertations/1304.
Council of Science Editors:
Johnston ML. A Bio-Inspired Self-Healing Polymer System for Sustainable Plastics. [Doctoral Dissertation]. Purdue University; 2015. Available from: https://docs.lib.purdue.edu/open_access_dissertations/1304
EPFL
14.
Manfredi, Erica.
Assessment of solvent capsule-based healing for woven fibre-reinforced epoxies.
Degree: 2015, EPFL
URL: http://infoscience.epfl.ch/record/206863
► Structural fibre-reinforced composites based on brittle matrices such as epoxy resins may be subject to short-term subcritical matrix damage that develops with time to the…
(more)
▼ Structural fibre-reinforced composites based on brittle matrices such as epoxy resins may be
subject to short-term subcritical matrix damage that develops with time to the point where it may compromise the integrity of the structure. Currently, components that have been damaged at the microscale are usually inspected and, depending on the extent of the damage, repaired with patches or entirely replaced.
Self-
healing functionality would prevent development of such damage by repairing it as soon as it appears, thereby increasing the service life of the material. Among the many potential methods for introducing
self-
healing capacity to epoxy resins, incorporation of solvent-filled capsules is particularly promising. Cracks cause the capsules to break, releasing a solvent that is able to swell the crack faces and induce reaction of residual monomer and/or crosslinkable functional groups intentionally left by under-curing the matrix. Thus, a model system based on ethyl phenylacetate (EPA) has been shown to provide up to approximately 90% efficiency in recovering fracture toughness, and to effectively block fatigue crack propagation in pure epoxy resin. The present thesis focuses on the integration of a EPA solvent capsule-based
healing system into a glass fibre-reinforced epoxy and the assessment of its effectiveness in repairing static interply damage. EPA-filled capsules with diameters in the range of 90-250 ÎŒm were produced using an oil-in-water emulsion technique and characterized in terms of their thermal stability and mechanical properties. Pure urea-formaldehyde (UF) as well as polyurethane/urea-formaldehyde (PU/UF) double wall capsule shell materials were analysed, showing that the wall thickness of pure UF capsules is independent of their diameter, whereas that of PU/UF capsules is 4 to 6 times greater and scales with the capsule diameter until a saturation value. The modulus of these shell materials was quantified using compression test and an analytical model, and found to range from 1 to 4 GPa depending on the amount of PU content in the shell composition. Bursting forces varied from 5 to 25 mN depending on the shell composition and diameter, thus providing a range of shell compositions to select from in order to tune the capsule behaviour. The integration of the capsules into the composite was carried out by dispersing them manually onto the reinforcement textile prior to processing. During this phase, the optimum capsule size range, position and concentration could be selected to fit in the interstices and survive textile packing. Textile packing properties were tested in compression; the presence of capsules led to a decrease of the reinforcement volume fraction at a given applied load value, in particular at low packing loads, and affected the usual power law behaviour of a textile in compression, up to the rupture of the capsules. Longitudinal permeability was also increased by a factor of 6 to 8 in presence of capsules for a given reinforcement volume fraction, whereas the transverse permeability was…
Advisors/Committee Members: Michaud, Véronique.
Subjects/Keywords: Self-healing; solvent healing; capsules; fibre-reinforced polymers; swelling; VARIM; DCB
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APA (6th Edition):
Manfredi, E. (2015). Assessment of solvent capsule-based healing for woven fibre-reinforced epoxies. (Thesis). EPFL. Retrieved from http://infoscience.epfl.ch/record/206863
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):
Manfredi, Erica. “Assessment of solvent capsule-based healing for woven fibre-reinforced epoxies.” 2015. Thesis, EPFL. Accessed October 17, 2019.
http://infoscience.epfl.ch/record/206863.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Manfredi, Erica. “Assessment of solvent capsule-based healing for woven fibre-reinforced epoxies.” 2015. Web. 17 Oct 2019.
Vancouver:
Manfredi E. Assessment of solvent capsule-based healing for woven fibre-reinforced epoxies. [Internet] [Thesis]. EPFL; 2015. [cited 2019 Oct 17].
Available from: http://infoscience.epfl.ch/record/206863.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Manfredi E. Assessment of solvent capsule-based healing for woven fibre-reinforced epoxies. [Thesis]. EPFL; 2015. Available from: http://infoscience.epfl.ch/record/206863
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Louisiana State University
15.
Aguirre Deras, Max Abelardo.
Micro-Encapsulation of Asphalt Rejuvenators using Melamine-Formaldehyde.
Degree: MS, Construction Engineering and Management, 2015, Louisiana State University
URL: etd-11052015-170948
;
https://digitalcommons.lsu.edu/gradschool_theses/463
► Self-healing microencapsulation in asphalt concrete is an emerging technology that would allow this particular material to resist cracking damage caused by vehicular and environmental…
(more)
▼ Self-healing microencapsulation in asphalt concrete is an emerging technology that would allow this particular material to resist cracking damage caused by vehicular and environmental loading. The objectives of this study were to evaluate the effect of an asphalt rejuvenator on asphalt binder in reversing the aging process and to develop a synthesis procedure for the production of microencapsulation of asphalt rejuvenators. Production parameters such as agitation rate, heating temperature and EMA concentration were varied to determine the effect on microcapsules properties such as size, shell thickness and morphology. Based on the results of the experimental program, it was concluded that the use of PennzSuppress D as a rejuvenator was effective in partially reversing the aging of asphalt binder by positively influencing both the high temperature and low temperature grades of the binder 70-22. In contrast, the use of PennzSuppress D as a rejuvenator did only influence the low temperature grade of the binder 76-22 and the high temperature grade of the RAP. A synthesis procedure was developed for the preparation of microencapsulation of PennzSuppress D and to characterize microcapsule properties such as diameter, shell thickness and morphology of the prepared microcapsules.
Subjects/Keywords: self-healing asphalt; microcapsules; crack repair; healing agent
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APA (6th Edition):
Aguirre Deras, M. A. (2015). Micro-Encapsulation of Asphalt Rejuvenators using Melamine-Formaldehyde. (Masters Thesis). Louisiana State University. Retrieved from etd-11052015-170948 ; https://digitalcommons.lsu.edu/gradschool_theses/463
Chicago Manual of Style (16th Edition):
Aguirre Deras, Max Abelardo. “Micro-Encapsulation of Asphalt Rejuvenators using Melamine-Formaldehyde.” 2015. Masters Thesis, Louisiana State University. Accessed October 17, 2019.
etd-11052015-170948 ; https://digitalcommons.lsu.edu/gradschool_theses/463.
MLA Handbook (7th Edition):
Aguirre Deras, Max Abelardo. “Micro-Encapsulation of Asphalt Rejuvenators using Melamine-Formaldehyde.” 2015. Web. 17 Oct 2019.
Vancouver:
Aguirre Deras MA. Micro-Encapsulation of Asphalt Rejuvenators using Melamine-Formaldehyde. [Internet] [Masters thesis]. Louisiana State University; 2015. [cited 2019 Oct 17].
Available from: etd-11052015-170948 ; https://digitalcommons.lsu.edu/gradschool_theses/463.
Council of Science Editors:
Aguirre Deras MA. Micro-Encapsulation of Asphalt Rejuvenators using Melamine-Formaldehyde. [Masters Thesis]. Louisiana State University; 2015. Available from: etd-11052015-170948 ; https://digitalcommons.lsu.edu/gradschool_theses/463
Louisiana State University
16.
Tavangarian, Fariborz.
Crack Self-Healing in SiC/Spinel Nanocomposite.
Degree: PhD, Mechanical Engineering, 2014, Louisiana State University
URL: etd-11042014-175430
;
https://digitalcommons.lsu.edu/gradschool_dissertations/1980
► Spinel is one of the best known and widely used ceramic materials. It has good thermal shock resistance, high chemical inertness in both acidic and…
(more)
▼ Spinel is one of the best known and widely used ceramic materials. It has good thermal shock resistance, high chemical inertness in both acidic and basic environments, excellent optical and dielectric properties, high strength at both elevated and normal temperatures, and has no phase transition up to the melting temperature (2135°C). Spinel is used in the metallurgical, electrochemical, and chemical industrial fields. It has also found some applications in dentistry, catalyst supports, humidity sensors, reinforcing fibers, photoluminescent materials, etc. One of the limitations of spinel ceramic is its brittleness. Furthermore, at high temperature applications, a rapid heating or cooling can cause a high thermal gradient. Building up of such thermal stresses can lead to surface microcracking and crack growth, which finally can lead to a catastrophic failure of the component. In order to overcome this problem, it is highly desirable that the self-healing capability of spinel and spinel composites are investigated. In this research for the first time we studied the crack self-healing capability of nanostructure spinel. The results showed that grain growth and sintering phenomena are the two factors controlling the healing procedures. In the case of spinel ceramic, cracks can be completely healed after annealing the specimens at 1600°C for 100h with the strength recovery of 91%. On the other hand, it has been found that SiC can be used as a healing agent in many ceramics even in those ceramics without any crack healing ability. Therefore, first SiC/spinel nanocomposite was synthesized using talc, aluminum and graphite powders. The sintering behavior of the SiC/spinel nanocomposite was investigated and the best pellets from physical and mechanical properties point of views were selected to study the self-healing behavior of SiC/spinel nanocomposite. The results showed that SiC/spinel nanocomposite has an exceptional crack-healing ability as the surface cracks can be healed after sintering the specimens at 1550°C for 1 min in air with the strength recovery of 99%. Reaction of SiC with air and formation of SiO2 and subsequently formation of mullite and dissociation of enstatite are the possible mechanisms responsible for crack healing in SiC/spinel nanocomposite.
Subjects/Keywords: Ceramics; SiC; Spinel; Self-healing; Crack-healing; Nanocomposite; Nanostructure
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CSE |
Export
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Manager
APA (6th Edition):
Tavangarian, F. (2014). Crack Self-Healing in SiC/Spinel Nanocomposite. (Doctoral Dissertation). Louisiana State University. Retrieved from etd-11042014-175430 ; https://digitalcommons.lsu.edu/gradschool_dissertations/1980
Chicago Manual of Style (16th Edition):
Tavangarian, Fariborz. “Crack Self-Healing in SiC/Spinel Nanocomposite.” 2014. Doctoral Dissertation, Louisiana State University. Accessed October 17, 2019.
etd-11042014-175430 ; https://digitalcommons.lsu.edu/gradschool_dissertations/1980.
MLA Handbook (7th Edition):
Tavangarian, Fariborz. “Crack Self-Healing in SiC/Spinel Nanocomposite.” 2014. Web. 17 Oct 2019.
Vancouver:
Tavangarian F. Crack Self-Healing in SiC/Spinel Nanocomposite. [Internet] [Doctoral dissertation]. Louisiana State University; 2014. [cited 2019 Oct 17].
Available from: etd-11042014-175430 ; https://digitalcommons.lsu.edu/gradschool_dissertations/1980.
Council of Science Editors:
Tavangarian F. Crack Self-Healing in SiC/Spinel Nanocomposite. [Doctoral Dissertation]. Louisiana State University; 2014. Available from: etd-11042014-175430 ; https://digitalcommons.lsu.edu/gradschool_dissertations/1980
University of Illinois – Urbana-Champaign
17.
Caruso, Mary M.
Solvent-based self-healing polymeric materials.
Degree: PhD, 0335, 2010, University of Illinois – Urbana-Champaign
URL: http://hdl.handle.net/2142/16824
► Mechanical damage to bulk polymers typically begins as a microcrack, which can lead to eventual failure of the material if there is no method to…
(more)
▼ Mechanical damage to bulk polymers typically begins as a microcrack, which can lead to eventual failure of the material if there is no method to inhibit crack growth. In living systems, this damage automatically initiates a
healing response. Following the example of nature,
self-
healing polymers are engineered with the unique ability to extend the lifetime of materials by preventing damage propagation using various chemical mechanisms that are triggered by crack formation. The initial chemistry for
self-
healing materials employed a room temperature ring-opening metathesis polymerization (ROMP) using encapsulated dicyclopentadiene (DCPD) and wax-protected Grubbs??? catalyst. However the limitations of this system, including catalyst availability, cost, environmental toxicity, stability, and materials processing, motivated the search for a simpler approach to
self-
healing.
Many chemical reactions require the use of a solvent. When an organic solvent is introduced into polymer systems, the mobility of polymer chains increases as the localized glass transition temperature is depressed. Solvent-based
self-
healing involves wetting of the polymer surface and resultant swelling of the bulk material, leading to interlocking of the polymer chains across a damaged crack plane to recover virgin mechanical properties. To achieve this
healing in an autonomic fashion, liquid-filled microcapsules were prepared with various core components and embedded within a bulk polymer during processing. By compartmentalizing reactive fluids containing a solvent into a bulk material, in situ reactions occur upon damage in the form of a crack. A crack propagating through the polymeric material ruptures the embedded microcapsules, thus releasing solvent-based mixtures into the crack plane.
The encapsulation of various solvents has been developed for use in
self-
healing polymers. Solvent-filled microcapsules were incorporated into thermoset matrices and thermoplastic materials such as poly(methyl methacrylate), and the
healing performance is discussed in great detail. A
self-
healing bone cement/dental resin system based on free-radical polymerization reactions has also been studied. The development of solvent-based microcapsules led to the encapsulation of conductive materials for the repair of mechanically damaged electronic devices. Finally, additional research was carried out to examine the use of solid and protected amines for high temperature
self-
healing systems.
Advisors/Committee Members: Moore, Jeffrey S. (advisor), Moore, Jeffrey S. (Committee Chair), Silverman, Scott K. (committee member), Zimmerman, Steven C. (committee member), White, Scott R. (committee member).
Subjects/Keywords: self-healing; polymers; solvent healing; microcapsules; fracture toughness; bone cement
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Caruso, M. M. (2010). Solvent-based self-healing polymeric materials. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/16824
Chicago Manual of Style (16th Edition):
Caruso, Mary M. “Solvent-based self-healing polymeric materials.” 2010. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed October 17, 2019.
http://hdl.handle.net/2142/16824.
MLA Handbook (7th Edition):
Caruso, Mary M. “Solvent-based self-healing polymeric materials.” 2010. Web. 17 Oct 2019.
Vancouver:
Caruso MM. Solvent-based self-healing polymeric materials. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2010. [cited 2019 Oct 17].
Available from: http://hdl.handle.net/2142/16824.
Council of Science Editors:
Caruso MM. Solvent-based self-healing polymeric materials. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2010. Available from: http://hdl.handle.net/2142/16824
University of Manchester
18.
Bingham, Ruth.
Corrosion protection and self-healing in nanocomposite coatings.
Degree: PhD, 2011, University of Manchester
URL: https://www.research.manchester.ac.uk/portal/en/theses/corrosion-protection-and-selfhealing-in-nanocomposite-coatings(d1419ee3-a028-401a-80c2-2151f7f1f633).html
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.538401
► Recent interest in environmentally friendly alternatives to chromate-based corrosion inhibitors has led to the development of a range of novel coating formulations. The work described…
(more)
▼ Recent interest in environmentally friendly alternatives to chromate-based corrosion inhibitors has led to the development of a range of novel coating formulations. The work described in this thesis has been aimed at investigating the mechanism of self-healing and active corrosion protection of the new coatings by searching for active components that have migrated from the coating to a controlled defect. The use of glow discharge optical emission spectroscopy (GDOES) has been investigated as a tool for both the generation of a reproducible controlled defect and for elemental depth profiling of the coatings and corroded substrates. Conclusions drawn from the elemental depth profiles have been validated by a range of characterisation techniques including optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDX) and electrochemical techniques. The work has focused particularly on a comparison of hybrid coatings doped with inhibitors encapsulated in nano-containers, as compared with the direct addition of inhibitor species to the coating matrix. The work also investigates the effects of inhibitor addition to sol-gel coatings or primer systems or both, highlighting possible synergistic effects of mixed inhibitor systems (for example, sol-gel coating doped with strontium aluminium polyphosphate (SAPP)) supporting primers doped with benzotriazol (BZT) or mercaptobenzothiazol (MBT). The various coatings have also been studied in the absence of inhibitor species to assess the effectiveness of the coatings as barriers between the substrate and the corrosive environment. This aspect of the study has highlighted minor inhibitive effects of some of the reagents used in the coating formulations and a major inhibitive effect of the nano-containers. The work therefore concludes with recommendations for a possible coating formulation combining the most beneficial elements of the various coatings investigated.
Subjects/Keywords: 669; Corrosion; Self-healing; Nanomaterials; Coatings; GDOES
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Bingham, R. (2011). Corrosion protection and self-healing in nanocomposite coatings. (Doctoral Dissertation). University of Manchester. Retrieved from https://www.research.manchester.ac.uk/portal/en/theses/corrosion-protection-and-selfhealing-in-nanocomposite-coatings(d1419ee3-a028-401a-80c2-2151f7f1f633).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.538401
Chicago Manual of Style (16th Edition):
Bingham, Ruth. “Corrosion protection and self-healing in nanocomposite coatings.” 2011. Doctoral Dissertation, University of Manchester. Accessed October 17, 2019.
https://www.research.manchester.ac.uk/portal/en/theses/corrosion-protection-and-selfhealing-in-nanocomposite-coatings(d1419ee3-a028-401a-80c2-2151f7f1f633).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.538401.
MLA Handbook (7th Edition):
Bingham, Ruth. “Corrosion protection and self-healing in nanocomposite coatings.” 2011. Web. 17 Oct 2019.
Vancouver:
Bingham R. Corrosion protection and self-healing in nanocomposite coatings. [Internet] [Doctoral dissertation]. University of Manchester; 2011. [cited 2019 Oct 17].
Available from: https://www.research.manchester.ac.uk/portal/en/theses/corrosion-protection-and-selfhealing-in-nanocomposite-coatings(d1419ee3-a028-401a-80c2-2151f7f1f633).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.538401.
Council of Science Editors:
Bingham R. Corrosion protection and self-healing in nanocomposite coatings. [Doctoral Dissertation]. University of Manchester; 2011. Available from: https://www.research.manchester.ac.uk/portal/en/theses/corrosion-protection-and-selfhealing-in-nanocomposite-coatings(d1419ee3-a028-401a-80c2-2151f7f1f633).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.538401
Louisiana State University
19.
Nji, Jones.
A Biomimic Self-healing Shape Memory Polymer Based Syntactic Foam for Smart Structural Composites.
Degree: PhD, Mechanical Engineering, 2011, Louisiana State University
URL: etd-04142011-124037
;
https://digitalcommons.lsu.edu/gradschool_dissertations/177
► This study explored the development of a new self-healing Polystyrene Shape Memory Polymer (PSMP) based syntactic foam for service life extension in structural polymeric composites.…
(more)
▼ This study explored the development of a new self-healing Polystyrene Shape Memory Polymer (PSMP) based syntactic foam for service life extension in structural polymeric composites. The objective was to self-heal structural-length scale damage in an autonomous, efficient, timely and repeatable manner at the molecular-length scale. Self-healing is achieved through a novel two step close-then-heal (CTH) self-healing scheme, designed to mimic the natural biological process of wound healing in humans. A new methodology to fabricate three-dimensional (3-D) fiber reinforced shape memory polymer syntactic foam for structural applications was developed. The effect of impact energy on the ability for the 3-D fiber reinforced PSMP syntactic foam (PSMP-SF) panels to seal cracks and mitigate impact was investigated in terms of the number of impacts to complete perforation. It was found that by restoring surface dents and closing internal crack, perforation was delayed (from 9 impacts to 16 impacts at 32 J impact energy) and (from 5 impacts to 7 impacts at 42 J impact energy). A new self-healing particulate composite was developed by incorporating co-polyester thermoplastic particles (6% by volume) within the PSMP matrix. The self-healing behavior of the composite was studied on single edge notched bend (SENB) specimens through three-point bending tests. Miscibility between the PSMP and the CP was validated through differential scanning calorimetric (DSC) analysis. It was found that the composite can heal structural-length scale damage at the molecular level in 20 minutes at 150 °C. Measured in terms of fracture load, a repeatable healing efficiency of 65% was obtained. The effect of thermoplastic content on self-healing efficiency and fracture toughness of the new self-healing particulate composite was investigated. It was found that the healing efficiency increased with thermoplastic content. However, the fracture toughness of the composite decreased in the same direction. The healing efficiencies at 3% and 9% CP volume fraction were respectively 50% and 75%. A new biomimetic self-healing syntactic foam was developed and shown to heal structural-length scale damage with a healing efficiency of 50% based on fracture load in three-point bending test. Repeated impact and self-healing tests revealed excellent impact tolerance and superior impact mitigation capabilities.
Subjects/Keywords: Syntactic Foam; Shape Memory Polymer; Self-Healing
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Nji, J. (2011). A Biomimic Self-healing Shape Memory Polymer Based Syntactic Foam for Smart Structural Composites. (Doctoral Dissertation). Louisiana State University. Retrieved from etd-04142011-124037 ; https://digitalcommons.lsu.edu/gradschool_dissertations/177
Chicago Manual of Style (16th Edition):
Nji, Jones. “A Biomimic Self-healing Shape Memory Polymer Based Syntactic Foam for Smart Structural Composites.” 2011. Doctoral Dissertation, Louisiana State University. Accessed October 17, 2019.
etd-04142011-124037 ; https://digitalcommons.lsu.edu/gradschool_dissertations/177.
MLA Handbook (7th Edition):
Nji, Jones. “A Biomimic Self-healing Shape Memory Polymer Based Syntactic Foam for Smart Structural Composites.” 2011. Web. 17 Oct 2019.
Vancouver:
Nji J. A Biomimic Self-healing Shape Memory Polymer Based Syntactic Foam for Smart Structural Composites. [Internet] [Doctoral dissertation]. Louisiana State University; 2011. [cited 2019 Oct 17].
Available from: etd-04142011-124037 ; https://digitalcommons.lsu.edu/gradschool_dissertations/177.
Council of Science Editors:
Nji J. A Biomimic Self-healing Shape Memory Polymer Based Syntactic Foam for Smart Structural Composites. [Doctoral Dissertation]. Louisiana State University; 2011. Available from: etd-04142011-124037 ; https://digitalcommons.lsu.edu/gradschool_dissertations/177
University of Illinois – Chicago
20.
Ariyan, Mansoore.
Mechanokinetic coupled Modeling of Self-Healing Behavior in Materials.
Degree: 2014, University of Illinois – Chicago
URL: http://hdl.handle.net/10027/11210
► Many inspiration in biological science world strike exciting opportunities in material science and led to a range of biomimetic and other advanced functional materials for…
(more)
▼ Many inspiration in biological science world strike exciting opportunities in material science and led to a range of biomimetic and other advanced functional materials for engineering and medical applications. The
self-controlled smart behavior of these systems make their individual functional components sense and process the environment and take necessary actions, similar to a living creature. This smart action is referred to a progressive change of material internal structure and chemical composition at a macroscopic interval of time. The dynamic internal structure results in varying constitutive properties and viewed as an adequate response of the material to external loading. The slow-rate evolution of constitutive properties of the materials is often affected by non-elastomechanical nature, such as phase transitions, chemical reactions, diffusion and other kinetic processes at the atomic scale. Additionally, the interplay between the mechanical performance and the internal structure dynamics can be two-way. This indicates that mechanical stress or strain in such material may trigger or affect kinetic processes responsible for its internal structure evolution; in turn, the changed internal structure may influence bulk properties and therefore mechanical response of the material to the external loading.
In this study, a nondeterministic multiple scale approach based on numerical solution of the Monte-Carlo master equation on atomic lattices solved together with a standard
vi
Finite-Element formulation of solid mechanics is investigated. This approach is applicable to long-term evolutionary processes such as precipitation, volume diffusion and creep cavity
self-
healing in nano-crystalline austenite (Fe fcc) samples. A two-way mechanokinetic coupling is achieved through implementation of strain- dependent diffusion rates and dynamic update of the finite element model based on atomic structure evolution. This study also discusses the effect of macroscopic static loading and cavity geometry on the total
healing time. The approach is used in application of modeling and characterization of advanced functional materials with evolutionary internal structures, and emerging behavior in material systems. In the current research we are studying a nondeterministic multiple scale approach based on numerical solution of the Monte-Carlo master equation on atomic lattices which is solved together with a standard Finite-Element formulation of solid mechanics. This approach is applicable to long-term evolutionary processes such as precipitation, volume diffusion and creep cavity
self-
healing in nanocrystalline austenite (Fe fcc) samples. A two-way mechanokinetic coupling is achieved through implementation of strain-dependent diffusion rates and dynamic update of the finite element model based on atomi structure evolution. This study also discusses the effect of macroscopic static loading and cavity geometry on the total
healing time. The approach is used in application of modeling and characterization of advanced functional…
Advisors/Committee Members: Karpov, Eduard (advisor).
Subjects/Keywords: Self-healing materials; Monte Carlo; Finite Elements
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Ariyan, M. (2014). Mechanokinetic coupled Modeling of Self-Healing Behavior in Materials. (Thesis). University of Illinois – Chicago. Retrieved from http://hdl.handle.net/10027/11210
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):
Ariyan, Mansoore. “Mechanokinetic coupled Modeling of Self-Healing Behavior in Materials.” 2014. Thesis, University of Illinois – Chicago. Accessed October 17, 2019.
http://hdl.handle.net/10027/11210.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Ariyan, Mansoore. “Mechanokinetic coupled Modeling of Self-Healing Behavior in Materials.” 2014. Web. 17 Oct 2019.
Vancouver:
Ariyan M. Mechanokinetic coupled Modeling of Self-Healing Behavior in Materials. [Internet] [Thesis]. University of Illinois – Chicago; 2014. [cited 2019 Oct 17].
Available from: http://hdl.handle.net/10027/11210.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Ariyan M. Mechanokinetic coupled Modeling of Self-Healing Behavior in Materials. [Thesis]. University of Illinois – Chicago; 2014. Available from: http://hdl.handle.net/10027/11210
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Manchester
21.
Bingham, Ruth.
Corrosion Protection and Self-healing in Nanocomposite
Coatings.
Degree: 2011, University of Manchester
URL: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:124590
► Ruth Violet Bingham, PhD Thesis, The University of Manchester. Corrosion Protection and Self-healing in Nanocomposite Coatings. 2011Abstract:Recent interest in environmentally friendly alternatives to chromate-based corrosion…
(more)
▼ Ruth Violet Bingham, PhD Thesis, The University of
Manchester. Corrosion Protection and
Self-
healing in Nanocomposite
Coatings. 2011Abstract:Recent interest in environmentally friendly
alternatives to chromate-based corrosion inhibitors has led to the
development of a range of novel coating formulations. The work
described in this thesis has been aimed at investigating the
mechanism of
self-
healing and active corrosion protection of the
new coatings by searching for active components that have migrated
from the coating to a controlled defect. The use of glow discharge
optical emission spectroscopy (GDOES) has been investigated as a
tool for both the generation of a reproducible controlled defect
and for elemental depth profiling of the coatings and corroded
substrates. Conclusions drawn from the elemental depth profiles
have been validated by a range of characterisation techniques
including optical microscopy, scanning electron microscopy,
energy-dispersive X-ray spectroscopy (EDX) and electrochemical
techniques.The work has focused particularly on a comparison of
hybrid coatings doped with inhibitors encapsulated in
nano-containers, as compared with the direct addition of inhibitor
species to the coating matrix. The work also investigates the
effects of inhibitor addition to sol-gel coatings or primer systems
or both, highlighting possible synergistic effects of mixed
inhibitor systems (for example, sol-gel coating doped with
strontium aluminium polyphosphate (SAPP) supporting primers doped
with benzotriazol (BZT) or mercaptobenzothiazol (MBT).The various
coatings have also been studied in the absence of inhibitor species
to assess the effectiveness of the coatings as barriers between the
substrate and the corrosive environment. This aspect of the study
has highlighted minor inhibitive effects of some of the reagents
used in the coating formulations and a major inhibitive effect of
the nano-containers. The work therefore concludes with
recommendations for a possible coating formulation combining the
most beneficial elements of the various coatings
investigated.
Advisors/Committee Members: Thompson, George.
Subjects/Keywords: Corrosion; Self-healing; Nanomaterials; Coatings; GDOES
Record Details
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Bingham, R. (2011). Corrosion Protection and Self-healing in Nanocomposite
Coatings. (Doctoral Dissertation). University of Manchester. Retrieved from http://www.manchester.ac.uk/escholar/uk-ac-man-scw:124590
Chicago Manual of Style (16th Edition):
Bingham, Ruth. “Corrosion Protection and Self-healing in Nanocomposite
Coatings.” 2011. Doctoral Dissertation, University of Manchester. Accessed October 17, 2019.
http://www.manchester.ac.uk/escholar/uk-ac-man-scw:124590.
MLA Handbook (7th Edition):
Bingham, Ruth. “Corrosion Protection and Self-healing in Nanocomposite
Coatings.” 2011. Web. 17 Oct 2019.
Vancouver:
Bingham R. Corrosion Protection and Self-healing in Nanocomposite
Coatings. [Internet] [Doctoral dissertation]. University of Manchester; 2011. [cited 2019 Oct 17].
Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:124590.
Council of Science Editors:
Bingham R. Corrosion Protection and Self-healing in Nanocomposite
Coatings. [Doctoral Dissertation]. University of Manchester; 2011. Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:124590
University of Cambridge
22.
Giannaros, Petros.
Laboratory and field investigation of the performance of novel microcapsule-based self-healing concrete.
Degree: PhD, 2017, University of Cambridge
URL: https://www.repository.cam.ac.uk/handle/1810/269924
;
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.744346
► Concrete, a composite material consisting of aggregates bound together with cement paste, is the most widely used construction material. Concrete is relatively cheap, very versatile…
(more)
▼ Concrete, a composite material consisting of aggregates bound together with cement paste, is the most widely used construction material. Concrete is relatively cheap, very versatile and has excellent compressive strength. However, its tensile strength is limited and for this reason steel rebars are often added to create reinforced concrete (RC). Cracking inevitably occurs in all RC materials and associated structures due to a variety of mechanical and environmental actions. The generation of tiny microcracks within concrete facilitates the flow of potentially aggressive fluids that can corrode the embedded steel rebars and, in extreme cases, lead to premature structural failure. Concrete, along with all cement-based materials, does possess some inherent self-healing capacity and is able to heal certain-size cracks autogenously. This self-healing capability is very limited and therefore researchers have attempted to improve upon it by using a variety of techniques. In particular, the use of engineered additions for autonomic self-healing has gained significant interest in the past two decades. An example is the addition of microcapsules that disperse throughout the hardened material subsequently providing reservoirs of healing agents. When cracks arise within the material, they rupture the embedded microcapsules causing a release of their contents into the crack volume. The released material then reacts to provide filling, sealing and healing of the crack. The primary aim of this research project was to investigate the autonomic self-healing performance of concrete containing microencapsulated sodium silicate. The effect of microcapsule addition on the fresh, hardened and self-healing properties of cement, mortar and concrete were all explored. Self-healing was monitored using a variety of techniques and results reveal the increased self-healing ability of microcapsule-containing cementitious materials as well as the efficacy of sodium silicate as a healing agent. Furthermore, the self-healing concrete field trial displays the great potential for microcapsules to be incorporated into large-scale self-healing concrete applications.
Subjects/Keywords: self-healing; concrete; microcapsules; autonomic; cementitious materials
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Giannaros, P. (2017). Laboratory and field investigation of the performance of novel microcapsule-based self-healing concrete. (Doctoral Dissertation). University of Cambridge. Retrieved from https://www.repository.cam.ac.uk/handle/1810/269924 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.744346
Chicago Manual of Style (16th Edition):
Giannaros, Petros. “Laboratory and field investigation of the performance of novel microcapsule-based self-healing concrete.” 2017. Doctoral Dissertation, University of Cambridge. Accessed October 17, 2019.
https://www.repository.cam.ac.uk/handle/1810/269924 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.744346.
MLA Handbook (7th Edition):
Giannaros, Petros. “Laboratory and field investigation of the performance of novel microcapsule-based self-healing concrete.” 2017. Web. 17 Oct 2019.
Vancouver:
Giannaros P. Laboratory and field investigation of the performance of novel microcapsule-based self-healing concrete. [Internet] [Doctoral dissertation]. University of Cambridge; 2017. [cited 2019 Oct 17].
Available from: https://www.repository.cam.ac.uk/handle/1810/269924 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.744346.
Council of Science Editors:
Giannaros P. Laboratory and field investigation of the performance of novel microcapsule-based self-healing concrete. [Doctoral Dissertation]. University of Cambridge; 2017. Available from: https://www.repository.cam.ac.uk/handle/1810/269924 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.744346
University of Cambridge
23.
Giannaros, Petros.
Laboratory and field investigation of the performance of novel microcapsule-based self-healing concrete
.
Degree: 2017, University of Cambridge
URL: https://www.repository.cam.ac.uk/handle/1810/269924
► Concrete, a composite material consisting of aggregates bound together with cement paste, is the most widely used construction material. Concrete is relatively cheap, very versatile…
(more)
▼ Concrete, a composite material consisting of aggregates bound together with cement paste, is the most widely used construction material. Concrete is relatively cheap, very versatile and has excellent compressive strength. However, its tensile strength is limited and for this reason steel rebars are often added to create reinforced concrete (RC). Cracking inevitably occurs in all RC materials and associated structures due to a variety of mechanical and environmental actions. The generation of tiny microcracks within concrete facilitates the flow of potentially aggressive fluids that can corrode the embedded steel rebars and, in extreme cases, lead to premature structural failure.
Concrete, along with all cement-based materials, does possess some inherent self-healing capacity and is able to heal certain-size cracks autogenously. This self-healing capability is very limited and therefore researchers have attempted to improve upon it by using a variety of techniques. In particular, the use of engineered additions for autonomic self-healing has gained significant interest in the past two decades. An example is the addition of microcapsules that disperse throughout the hardened material subsequently providing reservoirs of healing agents. When cracks arise within the material, they rupture the embedded microcapsules causing a release of their contents into the crack volume. The released material then reacts to provide filling, sealing and healing of the crack.
The primary aim of this research project was to investigate the autonomic self-healing performance of concrete containing microencapsulated sodium silicate. The effect of microcapsule addition on the fresh, hardened and self-healing properties of cement, mortar and concrete were all explored. Self-healing was monitored using a variety of techniques and results reveal the increased self-healing ability of microcapsule-containing cementitious materials as well as the efficacy of sodium silicate as a healing agent. Furthermore, the self-healing concrete field trial displays the great potential for microcapsules to be incorporated into large-scale self-healing concrete applications.
Subjects/Keywords: self-healing;
concrete;
microcapsules;
autonomic;
cementitious materials
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APA (6th Edition):
Giannaros, P. (2017). Laboratory and field investigation of the performance of novel microcapsule-based self-healing concrete
. (Thesis). University of Cambridge. Retrieved from https://www.repository.cam.ac.uk/handle/1810/269924
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):
Giannaros, Petros. “Laboratory and field investigation of the performance of novel microcapsule-based self-healing concrete
.” 2017. Thesis, University of Cambridge. Accessed October 17, 2019.
https://www.repository.cam.ac.uk/handle/1810/269924.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Giannaros, Petros. “Laboratory and field investigation of the performance of novel microcapsule-based self-healing concrete
.” 2017. Web. 17 Oct 2019.
Vancouver:
Giannaros P. Laboratory and field investigation of the performance of novel microcapsule-based self-healing concrete
. [Internet] [Thesis]. University of Cambridge; 2017. [cited 2019 Oct 17].
Available from: https://www.repository.cam.ac.uk/handle/1810/269924.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Giannaros P. Laboratory and field investigation of the performance of novel microcapsule-based self-healing concrete
. [Thesis]. University of Cambridge; 2017. Available from: https://www.repository.cam.ac.uk/handle/1810/269924
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Université Catholique de Louvain
24.
Brassinne, Jérémy.
Supramolecular interactions for controlling the structure, self-organization and dynamics of stimuli-responsive polymeric systems.
Degree: 2015, Université Catholique de Louvain
URL: http://hdl.handle.net/2078.1/165985
► In the last years, the advent of supramolecular chemistry has provided chemists with new possibilities to synthesize complex structures and dynamic materials by self-assembly. By…
(more)
▼ In the last years, the advent of supramolecular chemistry has provided chemists with new possibilities to synthesize complex structures and dynamic materials by self-assembly. By virtue of their properties, metal–ligand interactions are particularly promising for the synthesis of supramolecular polymers and the construction of “smart” materials with self-restructuring abilities. Among them, supramolecular gels constitute a very interesting sub-class because of numerous applications in various fields. In this frame, the goal of this thesis is to gain an unprecedented control over the structure, self-organization and molecular dynamics of polymeric gels by exploiting a novel combination of classical macromolecular architectures and supramolecular interactions of the metal–ligand type. The first goal of this thesis relies on the synthesis of well-defined copolymers, functionalized with a ligand of interest. These building blocks will then be used in the design of supramolecular materials with responsive properties. Precisely, the coordination of metal to ligands will be used to link micellar objects, obtained by the self-assembly of covalent block copolymers. The rheological behaviour of the accordingly obtained materials will be thoroughly characterized in order to establish relationships between their structure, dynamics and mechanical properties. The present thesis aims at studying in details the response of these systems to external stimuli. These stimuli-responsive properties will be inherent to the supramolecular materials and further obtained by using stimuli-responsive polymer sequences as building blocks.
(SC - Sciences) – UCL, 2015
Advisors/Committee Members: UCL - SST/IMCN/BSMA - Bio and soft matter, UCL - Faculté des Sciences, Gohy, Jean-François, Fustin, Charles-André, Bailly, Christian, Bouteiller, Laurent, van Ruymbeke, Evelyne, Vlassoupoulos, Dimitris, Devaux, Jacques.
Subjects/Keywords: Polymer; Supramolecular; Rheology; Material; Self-healing
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APA (6th Edition):
Brassinne, J. (2015). Supramolecular interactions for controlling the structure, self-organization and dynamics of stimuli-responsive polymeric systems. (Thesis). Université Catholique de Louvain. Retrieved from http://hdl.handle.net/2078.1/165985
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):
Brassinne, Jérémy. “Supramolecular interactions for controlling the structure, self-organization and dynamics of stimuli-responsive polymeric systems.” 2015. Thesis, Université Catholique de Louvain. Accessed October 17, 2019.
http://hdl.handle.net/2078.1/165985.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Brassinne, Jérémy. “Supramolecular interactions for controlling the structure, self-organization and dynamics of stimuli-responsive polymeric systems.” 2015. Web. 17 Oct 2019.
Vancouver:
Brassinne J. Supramolecular interactions for controlling the structure, self-organization and dynamics of stimuli-responsive polymeric systems. [Internet] [Thesis]. Université Catholique de Louvain; 2015. [cited 2019 Oct 17].
Available from: http://hdl.handle.net/2078.1/165985.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Brassinne J. Supramolecular interactions for controlling the structure, self-organization and dynamics of stimuli-responsive polymeric systems. [Thesis]. Université Catholique de Louvain; 2015. Available from: http://hdl.handle.net/2078.1/165985
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Deakin University
25.
Chaffraix, Thomas Louis Jacques Henri.
Self-healing dendrimers based on ionic or hydrogen-bonding supramolecular interactions.
Degree: 2014, Deakin University
URL: http://hdl.handle.net/10536/DRO/DU:30074317
This PhD project dealt with the development and characterisation of a number of metallo and hydrogen-bonded supramolecular dendrimers for applications in the area of self-healing materials
Advisors/Committee Members: Magniez, Kevin, Fox, Bronwyn.Subjects/Keywords: self-healing materials; supramolecular dendrimers; polymers
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APA (6th Edition):
Chaffraix, T. L. J. H. (2014). Self-healing dendrimers based on ionic or hydrogen-bonding supramolecular interactions. (Thesis). Deakin University. Retrieved from http://hdl.handle.net/10536/DRO/DU:30074317
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):
Chaffraix, Thomas Louis Jacques Henri. “Self-healing dendrimers based on ionic or hydrogen-bonding supramolecular interactions.” 2014. Thesis, Deakin University. Accessed October 17, 2019.
http://hdl.handle.net/10536/DRO/DU:30074317.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Chaffraix, Thomas Louis Jacques Henri. “Self-healing dendrimers based on ionic or hydrogen-bonding supramolecular interactions.” 2014. Web. 17 Oct 2019.
Vancouver:
Chaffraix TLJH. Self-healing dendrimers based on ionic or hydrogen-bonding supramolecular interactions. [Internet] [Thesis]. Deakin University; 2014. [cited 2019 Oct 17].
Available from: http://hdl.handle.net/10536/DRO/DU:30074317.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Chaffraix TLJH. Self-healing dendrimers based on ionic or hydrogen-bonding supramolecular interactions. [Thesis]. Deakin University; 2014. Available from: http://hdl.handle.net/10536/DRO/DU:30074317
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Illinois – Urbana-Champaign
26.
Kryger, Matthew J.
Synthesis and Development of Novel Cyclobutane Mechanophores.
Degree: PhD, 0335, 2012, University of Illinois – Urbana-Champaign
URL: http://hdl.handle.net/2142/31973
► Mechanical damage of polymers is often a destructive and irreversible process. However, desirable effects may be achieved by controlling the location of chain cleavage events…
(more)
▼ Mechanical damage of polymers is often a destructive and irreversible process. However, desirable effects may be achieved by controlling the location of chain cleavage events through careful design and incorporation of mechanically active chemical moieties known as mechanophores. These mechanophores could then be utilized for localized
self-
healing or
self-repair of polymer composites. To date there have been few attempts at systematically investigating the effects of mechanophore structure upon rates of activation. Through the synthesis and study of a systematic series of cyclobutane mechanophores, methodology was developed for measuring relative mechanophore reactivity rates and results from these studies were compared to experimentally determined reactivity rates. The straightforward calculations and experimental methods developed herein are useful in guiding the future design and development of new mechanophores for targeted applications including
self-repair or damage sensing in polymer composites. In addition to a systematic study of cyclobutane reactivity, the dicyano-substituted cyclobutane mechanophore was shown to form reactive cyanoacrylate-terminated polymers due to mechanically induced retro [2+2] cyclization of the cyclobutane when exposed to external stress. These reactively-terminated polymers have potential applications in
self-
healing.
Advisors/Committee Members: Moore, Jeffrey S. (advisor), Moore, Jeffrey S. (Committee Chair), Silverman, Scott K. (committee member), Zimmerman, Steven C. (committee member), White, Scott R. (committee member).
Subjects/Keywords: Polymer Chemistry; Mechanochemistry; Mechanophore; Cyclobutane; Self-healing
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APA (6th Edition):
Kryger, M. J. (2012). Synthesis and Development of Novel Cyclobutane Mechanophores. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/31973
Chicago Manual of Style (16th Edition):
Kryger, Matthew J. “Synthesis and Development of Novel Cyclobutane Mechanophores.” 2012. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed October 17, 2019.
http://hdl.handle.net/2142/31973.
MLA Handbook (7th Edition):
Kryger, Matthew J. “Synthesis and Development of Novel Cyclobutane Mechanophores.” 2012. Web. 17 Oct 2019.
Vancouver:
Kryger MJ. Synthesis and Development of Novel Cyclobutane Mechanophores. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2012. [cited 2019 Oct 17].
Available from: http://hdl.handle.net/2142/31973.
Council of Science Editors:
Kryger MJ. Synthesis and Development of Novel Cyclobutane Mechanophores. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2012. Available from: http://hdl.handle.net/2142/31973
University of Illinois – Urbana-Champaign
27.
McIlroy, David A.
Microencapsulation of reactive amines and isocyanates and their application to self-healing systems.
Degree: PhD, 0130, 2011, University of Illinois – Urbana-Champaign
URL: http://hdl.handle.net/2142/26401
► Microcapsule-based self-healing systems enable repair of crack damage in polymers and polymer matrix composites. Existing self-healing chemistries are limited by relatively weak chemical bonding between…
(more)
▼ Microcapsule-based
self-
healing systems enable repair of crack damage in polymers and polymer matrix composites. Existing
self-
healing chemistries are limited by relatively weak chemical bonding between the matrix and the
healing material, temperature stability, and side reactions that degrade the active components. We demonstrate for the first time a two-part system that incorporates a
healing chemistry similar to the matrix curing chemistry, enabling chemical bonding between the healed material and the matrix material. Amine-containing microcapsules are synthesized by interfacial polymerization of a polyurea about a droplet of amine by means of suspension polymerization. Capsules are subsequently isolated and analyzed for content, and shown to contain reactive amine.
The microcapsules containing reactive amine are employed in concert with microcapsules containing epoxy resin to recover fracture toughness in a cured epoxy. Both capsule types are dispersed in an epoxy resin and the resin is chemically cured. Mechanical load is applied to propagate a crack and rupture microcapsules contained within the cured resin. The average peak load at failure in a virgin specimen is recorded, and compared to the average peak load at failure in the same specimen after a
healing period. Recovery of fracture toughness is limited to 15% for specimens healed at temperatures of 50 °C and below, whereas
healing efficiencies of up to 60% are observed for specimens healed at temperatures above 80 °C. Control specimens where amine was not present failed to recover.
Microcapsules containing isocyanate are also prepared by means of interfacial polyurea condensation. These capsules are also isolated and analyzed for content, and shown to contain reactive isocyanate. No
healing was observed with these capsules, however, due to problems with bonding and long-term stability. With refinement, the isocyanate system is projected for use in polyurethane matrix materials where a moisture-cure could promote the
healing reaction.
Advisors/Committee Members: Sottos, Nancy R. (advisor), Sottos, Nancy R. (Committee Chair), White, Scott R. (committee member), Braun, Paul V. (committee member), Schweizer, Kenneth S. (committee member).
Subjects/Keywords: Self-Healing; Amine; Isocyanate; Epoxy; Microcapsule
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Manager
APA (6th Edition):
McIlroy, D. A. (2011). Microencapsulation of reactive amines and isocyanates and their application to self-healing systems. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/26401
Chicago Manual of Style (16th Edition):
McIlroy, David A. “Microencapsulation of reactive amines and isocyanates and their application to self-healing systems.” 2011. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed October 17, 2019.
http://hdl.handle.net/2142/26401.
MLA Handbook (7th Edition):
McIlroy, David A. “Microencapsulation of reactive amines and isocyanates and their application to self-healing systems.” 2011. Web. 17 Oct 2019.
Vancouver:
McIlroy DA. Microencapsulation of reactive amines and isocyanates and their application to self-healing systems. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2011. [cited 2019 Oct 17].
Available from: http://hdl.handle.net/2142/26401.
Council of Science Editors:
McIlroy DA. Microencapsulation of reactive amines and isocyanates and their application to self-healing systems. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2011. Available from: http://hdl.handle.net/2142/26401
University of Illinois – Urbana-Champaign
28.
Patel, Amit J.
Autonomic healing of low-velocity impact damage in woven fiber-reinforced composites.
Degree: PhD, 0130, 2011, University of Illinois – Urbana-Champaign
URL: http://hdl.handle.net/2142/24251
► Polymer-matrix fiber-reinforced composites have seen increasing use in applications requiring high specific strength and stiffness. These materials typically show excellent in-plane properties but are particularly…
(more)
▼ Polymer-matrix fiber-reinforced composites have seen increasing use in applications requiring high specific strength and stiffness. These materials typically show excellent in-plane properties but are particularly susceptible to transverse impacts. Impact can significantly reduce strength and the extent of damage can grow under cyclic loading conditions. Because this type of damage often occurs below the surface, hidden from inspection, it is especially critical in structural applications. Traditionally, impact damage repair techniques have focused on increased factors of safety or use of toughened polymer matrices. In this work, a microcapsule-based
self-
healing epoxy is used in woven fiber-reinforced composite panels for the repair of matrix damage imparted by low-velocity impact.
The initial work focused on
self-
healing in plain 2D woven S2 glass laminates with an epoxy matrix. The
self-
healing components, dicyclopentadiene (DCPD) microcapsules and wax-encapsulated first generation Grubbs' catalyst microspheres, were premixed into the liquid epoxy, and panels are fabricated using a hand layup technique and compression molding. Low-velocity impact damage was introduced to these panels by drop-weight impact testing. To visually assess the damage state, cracks on sections through the impact damage were marked with fluorescent dye penetrant. A 51% reduction in total crack length per imaged edge was observed for
self-
healing panels when compared to non-
healing controls, indicating filling of damage with healed material. A reduction in damage resistance was also observed upon inclusion of both
self-
healing components. Recovery of mechanical properties after
healing was investigated by conducting compression-after-impact tests.
Self-
healing panels showed full recovery of residual compressive strength up to a threshold impact energy nearly double that of non-
healing controls. Above this threshold impact energy, residual compressive strength was partially recovered to a degree that diminished with increasing impact energy.
The work on
self-
healing 2D woven composites indicated that catalyst microspheres significantly reduced damage resistance, while microcapsules did not have the same detrimental effect on damage resistance. Thus, potential improvements by the use of catalyst microspheres encapsulated by poly(urea-formaldehyde) (UF) were explored. To investigate the effect of encapsulating catalyst microspheres with UF on the mechanical properties, UF encapsulated wax microspheres were fabricated and investigated. Tapered double cantilever beam samples containing these UF encapsulated wax microspheres showed better mode I fracture toughness than samples containing wax microspheres. In addition, composite panels containing DCPD microcapsules and UF encapsulated microspheres exhibited higher impact damage resistance.
The recovery of impact damage in 3D orthogonal woven composites was also explored. Low-velocity impact damage in 2D plain woven and 3D orthogonal woven glass/epoxy composites was compared by developing and…
Advisors/Committee Members: White, Scott R. (advisor), White, Scott R. (Committee Chair), Sottos, Nancy R. (committee member), Braun, Paul V. (committee member), Cheng, Jianjun (committee member).
Subjects/Keywords: self-healing; woven composites; impact damage
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APA ·
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Export
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APA (6th Edition):
Patel, A. J. (2011). Autonomic healing of low-velocity impact damage in woven fiber-reinforced composites. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/24251
Chicago Manual of Style (16th Edition):
Patel, Amit J. “Autonomic healing of low-velocity impact damage in woven fiber-reinforced composites.” 2011. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed October 17, 2019.
http://hdl.handle.net/2142/24251.
MLA Handbook (7th Edition):
Patel, Amit J. “Autonomic healing of low-velocity impact damage in woven fiber-reinforced composites.” 2011. Web. 17 Oct 2019.
Vancouver:
Patel AJ. Autonomic healing of low-velocity impact damage in woven fiber-reinforced composites. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2011. [cited 2019 Oct 17].
Available from: http://hdl.handle.net/2142/24251.
Council of Science Editors:
Patel AJ. Autonomic healing of low-velocity impact damage in woven fiber-reinforced composites. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2011. Available from: http://hdl.handle.net/2142/24251
Miami University
29.
Ahammed, Ballal.
MOLECULAR DYNAMICS SIMULATION OF SELF-HEALING
POLYMERS.
Degree: MS, Mechanical & Manufacturing Engineering, 2019, Miami University
URL: http://rave.ohiolink.edu/etdc/view?acc_num=miami1564686567714321
► As the name implies, self-healing materials have the ability to heal itself with or withouthelp of external stimulus. Dynamically cross-linked polymer networks as self-healing materialshave…
(more)
▼ As the name implies,
self-
healing materials have the
ability to heal itself with or withouthelp of external stimulus.
Dynamically cross-linked polymer networks as
self-
healing
materialshave recently attracted significant attention of the
researchers due to their uniqueand improved properties like
increased toughness, malleability, shape memory, and
selfhealing.Moreover, depending on the cross-linker and their
cross-linking process dynamicallyCross-linked polymer gives rise to
different network structures with interesting propertieslike
increased mechanical strength and thermal conductivity. In this
thesis, Usingcoarse grain molecular dynamics simulation
self-
healing, mechanical and thermal propertiesof the dynamically
cross-linked polymers are investigated. Firstly, molecular
dynamicssimulation reproduced the
self-
healing behaviour observed
in the experiment. Then usingtime-dependent bond formation process
explained the effect of
healing time and compressiveforce on degree
of
self-
healing which is consistent with the experiments.
Secondly,MD simulation predicted higher mechanical strength of
Inter Penetrating Polymer network(IPN) over Singular Polymer
network (SN) which is supported by the experiment. Moreover,the MD
results show that the superior mechanical strength of IPN over SN
arises fromthe difference in spatial degrees of freedom of the
non-covalent cross-linkers in comparisonto covalent cross-linkers.
Lastly, Non-Equilibrium Molecular Dynamics simulation(NEMD)
predicted the higher thermal conductivity of IPN over SN.
Additionally, it explainedthe mechanism of thermal conductivity
enhancement due to the orientation of thepolymer chain by studying
the effect of mechanical strain. Finally, MD results showed
anincreasing trend of thermal conductivity with temperature in the
lower temperature range.
Advisors/Committee Members: Zanjani, Mehdi (Advisor), Ye, Zhijiang (Advisor).
Subjects/Keywords: Mechanical Engineering; Self-healing; Molecular Dynamics; Polymers
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Export
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Manager
APA (6th Edition):
Ahammed, B. (2019). MOLECULAR DYNAMICS SIMULATION OF SELF-HEALING
POLYMERS. (Masters Thesis). Miami University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=miami1564686567714321
Chicago Manual of Style (16th Edition):
Ahammed, Ballal. “MOLECULAR DYNAMICS SIMULATION OF SELF-HEALING
POLYMERS.” 2019. Masters Thesis, Miami University. Accessed October 17, 2019.
http://rave.ohiolink.edu/etdc/view?acc_num=miami1564686567714321.
MLA Handbook (7th Edition):
Ahammed, Ballal. “MOLECULAR DYNAMICS SIMULATION OF SELF-HEALING
POLYMERS.” 2019. Web. 17 Oct 2019.
Vancouver:
Ahammed B. MOLECULAR DYNAMICS SIMULATION OF SELF-HEALING
POLYMERS. [Internet] [Masters thesis]. Miami University; 2019. [cited 2019 Oct 17].
Available from: http://rave.ohiolink.edu/etdc/view?acc_num=miami1564686567714321.
Council of Science Editors:
Ahammed B. MOLECULAR DYNAMICS SIMULATION OF SELF-HEALING
POLYMERS. [Masters Thesis]. Miami University; 2019. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=miami1564686567714321
University of Illinois – Urbana-Champaign
30.
Krull, Brett Peter.
Microvascular strategies for damage restoration.
Degree: PhD, Materials Science and Engineering, 2015, University of Illinois – Urbana-Champaign
URL: http://hdl.handle.net/2142/89105
► Autonomous repair of synthetic materials has previously been demonstrated by the incorporation of biomimetic microvascular networks within structural polymers and polymer composites. Internal networks of…
(more)
▼ Autonomous repair of synthetic materials has previously been demonstrated by the incorporation of biomimetic microvascular networks within structural polymers and polymer composites. Internal networks of channels act as pathways for mass transport of liquid
healing agents to damage regions that intersect the vasculature. Microvascular
self-
healing has proven effective in restoring fracture toughness and modulus by re-bonding the surfaces of damage-induced microcracks; however, large damage volumes (crack separations > 100 µm) provide additional challenges. Capillary forces (i.e. surface tension) aid in retention of
healing agents within small crack separations, but gravity may draw
healing agents away from larger separations to prevent repair. Inspired by the ability of natural organisms to regenerate lost appendages, this dissertation explores the interaction between microvascular
self-
healing materials and large damage volumes with respect to
healing agent composition and delivery mechanism.
Previously reported
healing agent chemistries are either mechanically robust (epoxy-based) or rapid response (gels). Here, a two-stage polymer system is introduced in which a fast gelation (~30 s) is followed by free radical polymerization (>1 hr) to obtain a rapid-response system that subsequently cures into a structural polymer. Viscosity and surface tension are leveraged to optimize delivery and wetting properties. The
healing agents allow for the successful recovery of lost mass for through-thickness damage regions spanning up to 11.2 mm in thin epoxy sheets through the careful control of delivery parameters and sample geometry. Additionally, a series of epoxy-based
healing agents is characterized to determine response time, viscosity, surface tension, thermal performance, and fracture properties with the goal of improved
healing response. In addition to work involving the performance and function of microvascular systems, a technique for automatically tracking crack length in-situ is presented for the double cantilever beam specimens and a method for creating branched vasculature via 3D printing of poly(lactic acid) is introduced.
The components of two-part
healing agents must successfully mix in the damage region to obtain a
healing response. An air-driven flow system is developed to deliver alternating droplets of
healing agents into a damage region to achieve high levels of mixing. The final mixing efficiency of the healed region is determined via confocal fluorescent microscopy. A statistical analysis of embedded fluorescent nanospheres reveals the air-driven system greatly exceeds previously reported methods for inducing mixing of
healing agents in microvascular systems. In-situ delivery is demonstrated for a simulated delamination event in a double cantilever beam specimen. The damage event ruptures the microchannel and mixed droplets of epoxy-thiol
healing agents are delivered to the crack plane. Following fracture, droplet flow in the air-driven system is reinstated by crack closure, which continuously purges…
Advisors/Committee Members: Sottos, Nancy R. (advisor), Sottos, Nancy R. (Committee Chair), Braun, Paul V. (committee member), Kilian, Kristopher A. (committee member), White, Scott R. (committee member).
Subjects/Keywords: polymers; self-healing; microvascular; regeneration; microfluidics
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APA ·
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to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Krull, B. P. (2015). Microvascular strategies for damage restoration. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/89105
Chicago Manual of Style (16th Edition):
Krull, Brett Peter. “Microvascular strategies for damage restoration.” 2015. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed October 17, 2019.
http://hdl.handle.net/2142/89105.
MLA Handbook (7th Edition):
Krull, Brett Peter. “Microvascular strategies for damage restoration.” 2015. Web. 17 Oct 2019.
Vancouver:
Krull BP. Microvascular strategies for damage restoration. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2015. [cited 2019 Oct 17].
Available from: http://hdl.handle.net/2142/89105.
Council of Science Editors:
Krull BP. Microvascular strategies for damage restoration. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2015. Available from: http://hdl.handle.net/2142/89105
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Open Access Theses and Dissertations