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Author: Chad Daley Publisher: ISBN: Category : Languages : en Pages : 137
Book Description
In this thesis we describe two separate experiments involving the use of gold nanoparticles. The first experiment looks at the use of gold nanoparticles as a localized heat source and the potential application as a cancer treatment. The second experiment, which is the real focus of this thesis, applies gold nanoparticles in the study of the free surface dynamics of glassy thin films. Gold nanoparticles have the ability to strongly absorb the energy in an incident laser beam and convert that energy into heat. Photothermal therapy is a proposed cancer treatment which exploits this ability to irreparably damage cancerous tissues surrounding gold nanoparticles. In the first chapter of this thesis we explain an experiment designed to probe the local temperatures achieved in such a process. Gold nanoparticles are used to stabilize the boundary of an inverse micelle system which contains an aqueous fluorescent dye solution on it's interior. A temperature dependent fluorescence intensity allows us to probe the temperature changes induced by laser irradiation. In the remainder of this thesis we describe a separate experiment involving the use of gold nanoparticles to study the free surface dynamics of thin glassy films. There is a growing body of evidence in the literature that thin polymer films in the glassy state exhibit heterogeneous dynamics; specifically that the first few nanometers from an air-polymer interface exhibit enhanced mobility relative to the interior of the film. The underlying mechanism responsible for this enhanced mobility remains elusive, however some believe it to be a direct consequence of the polymeric nature of these films. We describe in detail an experiment aimed at addressing this concern. We deposit gold nanoparticles onto the surface of a molecular (non-polymeric) glassy film and monitor their behaviour upon heating using atomic force microscopy. Our results clearly show the existence of enhanced surface mobility in the system studied and provide strong evidence that enhanced surface mobility should be expected in all glass forming systems.
Author: Chad Daley Publisher: ISBN: Category : Languages : en Pages : 137
Book Description
In this thesis we describe two separate experiments involving the use of gold nanoparticles. The first experiment looks at the use of gold nanoparticles as a localized heat source and the potential application as a cancer treatment. The second experiment, which is the real focus of this thesis, applies gold nanoparticles in the study of the free surface dynamics of glassy thin films. Gold nanoparticles have the ability to strongly absorb the energy in an incident laser beam and convert that energy into heat. Photothermal therapy is a proposed cancer treatment which exploits this ability to irreparably damage cancerous tissues surrounding gold nanoparticles. In the first chapter of this thesis we explain an experiment designed to probe the local temperatures achieved in such a process. Gold nanoparticles are used to stabilize the boundary of an inverse micelle system which contains an aqueous fluorescent dye solution on it's interior. A temperature dependent fluorescence intensity allows us to probe the temperature changes induced by laser irradiation. In the remainder of this thesis we describe a separate experiment involving the use of gold nanoparticles to study the free surface dynamics of thin glassy films. There is a growing body of evidence in the literature that thin polymer films in the glassy state exhibit heterogeneous dynamics; specifically that the first few nanometers from an air-polymer interface exhibit enhanced mobility relative to the interior of the film. The underlying mechanism responsible for this enhanced mobility remains elusive, however some believe it to be a direct consequence of the polymeric nature of these films. We describe in detail an experiment aimed at addressing this concern. We deposit gold nanoparticles onto the surface of a molecular (non-polymeric) glassy film and monitor their behaviour upon heating using atomic force microscopy. Our results clearly show the existence of enhanced surface mobility in the system studied and provide strong evidence that enhanced surface mobility should be expected in all glass forming systems.
Author: Yue Zhang Publisher: ISBN: Category : Languages : en Pages : 0
Book Description
Nanometer-sized thin films of small organic molecules are widely used in applications ranging from organic electronics and pharmaceuticals to coatings and nano-imprint lithography. Studies show that properties of these nanometer-sized thin films deviate strongly from their bulk counterparts, possibly due to enhanced surface dynamics and increased surface-to-volume ratio. Developing new techniques that can readily measure the surface dynamics of an organic glass can help understand such phenomena. In this thesis, I will first introduce a novel technique that uses tobacco mosaic virus as the probe particle to directly measure surface diffusion on molecular glasses. The surface diffusion is measured to be greatly enhanced compared to bulk counterpart. The surface diffusion is also investigated on ultrastable glasses and aged glasses with suppressed relaxation dynamics and ultrathin glasses with overall enhanced dynamics. The surface diffusion is found to stay fast and invariant on molecular glasses with varying bulk relaxation dynamics, suggesting that the surface diffusion is decoupled from bulk relaxation dynamics and is only a purely free surface motion. Further, I combine a morphological probe tracking the isothermal dewetting process in ultrathin molecular glasses with cooling-rate dependent glass transition temperature measurements to study the propagation length scale of the surface enhancement effect. Results show that organic glass films with thicknesses of 30 nm or less have dynamics significantly enhanced relative to bulk, induced by the free surface. Furthermore, there is a sharp glass to liquid transition observed around 30 nm, indicating long-range correlated dynamics in ultrathin molecular glasses. While these studies are important for a host of applications, they can also help elucidate the fundamentals of interfacial effects in thin film systems.
Author: Nikhil Padhye Publisher: Springer Nature ISBN: 3030825590 Category : Science Languages : en Pages : 111
Book Description
This book bridges disparate fields in an exploration of the phenomena and applications surrounding molecular mobility in glassy materials experiencing inelastic deformation. The subjects of plastic deformation and polymer motion/interdiffusion currently belong to the two different fields of continuum mechanics and polymer physics, respectively. However, molecular motion associated with plastic deformation is a key ingredient to gain fundamental understanding, both at the macroscopic and microscopic level. This short monograph provides necessary background in the aforementioned fields before addressing the topic of molecular mobility accompanied by macroscopic inelastic deformation in an accessible and easy-to-understand manner. A new phenomenon of solid-state deformation-induced bonding in polymers is discussed in detail, along with some broad implications in several manufacturing sectors. Open questions pertaining to mechanisms, mechanics, and modeling of deformation-induced bonding in polymers are presented. The book’s clear language and careful explanations will speak to readers of diverse backgrounds.
Author: Connie B. Roth Publisher: CRC Press ISBN: 1315305135 Category : Science Languages : en Pages : 587
Book Description
"the present book will be of great value for both newcomers to the field and mature active researchers by serving as a coherent and timely introduction to some of the modern approaches, ideas, results, emerging understanding, and many open questions in this fascinating field of polymer glasses, supercooled liquids, and thin films" –Kenneth S. Schweizer, Morris Professor of Materials Science & Engineering, University of Illinois at Urbana-Champaign (from the Foreword) This book provides a timely and comprehensive overview of molecular level insights into polymer glasses in confined geometries and under deformation. Polymer glasses have become ubiquitous to our daily life, from the polycarbonate eyeglass lenses on the end of our nose to large acrylic glass panes holding water in aquarium tanks, with advantages over glass in that they are lightweight and easy to manufacture, while remaining transparent and rigid. The contents include an introduction to the field, as well as state of the art investigations. Chapters delve into studies of commonalities across different types of glass formers (polymers, small molecules, colloids, and granular materials), which have enabled microscopic and molecular level frameworks to be developed. The authors show how glass formers are modeled across different systems, thereby leading to treatments for polymer glasses with first-principle based approaches and molecular level detail. Readers across disciplines will benefit from this topical overview summarizing the key areas of polymer glasses, alongside an introduction to the main principles and approaches.
Author: Yu Chai Publisher: ISBN: Category : Condensed matter Languages : en Pages : 231
Book Description
How polymers behave near the glass transition is one of the deepest questions in condensed matter physics. In the past two decades, the surface dynamics, glass transition, and crystallization of polymer thin films have attracted much attention as they are not only scientific questions but also fundamentals of modern polymer industry. However, there are still many phenomena that are not clear, such as whether the glass transition is a real phase transition; whether there is an enhanced mobile layer near the free surface and how thick it is; whether the glass transition temperature reduction is caused by the free surface; whether some polymers cannot crystallize; etc. Here we try to gain insight into these questions. In this thesis, there are six chapters. The first chapter is introduction, in which some basic concepts and a literature review are presented. The second chapter contains the experimental details, in which the experimental techniques and data analysis methods are discussed. Chapter three, four, and five focus on three different research areas; however, these topics are related to each other. In chapter three, we conduct a novel stepped film levelling experiment to study the surface dynamics of polymer films near the glass transition temperature, in which several subtopics are involved, such as molecular weight dependent levelling, levelling under soft confinement, and ultra-thin films levelling. In chapter four, we find the direct evidence of the crystallization of atactic polystyrene, and systematically study the growth and melting kinetics of these crystals. In chapter five, the thermal expansivity of polystyrene thin films is measured using ellipsometry. These results confirm the validity of the recently proposed simple model, which connects the existence of an enhanced mobile layer near the free surface to the glass transition temperature reduction in thin films. The last chapter is concluding remarks and future work, in which a brief summary is included and some possible future studies are proposed.
Author: Toshiji Kanaya Publisher: Springer ISBN: 3642343392 Category : Technology & Engineering Languages : en Pages : 150
Book Description
Mobility Gradient of Polystyrene in Films Supported on Solid Substrates, by Yoshihisa Fujii, Hiroshi Morita, Atsushi Takahara and Keiji Tanaka Probing Properties of Polymers in Thin Films Via Dewetting, by Günter Reiter Heterogeneous and Aging Dynamics in Single and Stacked Thin Polymer Films, by Koji Fukao, Takehide Terasawa, Kenji Nakamura, Daisuke Tahara Heterogeneous Dynamics of Polymer Thin Films as Studied by Neutron Scattering, by Rintaro Inoue and Toshiji Kanaya
Author: Friedrich Kremer Publisher: Springer ISBN: 3319061003 Category : Technology & Engineering Languages : en Pages : 365
Book Description
This book describes the dynamics of low molecular weight and polymeric molecules when they are constrained under conditions of geometrical confinement. It covers geometrical confinement in different dimensionalities: (i) in nanometer thin layers or self supporting films (1-dimensional confinement) (ii) in pores or tubes with nanometric diameters (2-dimensional confinement) (iii) as micelles embedded in matrices (3-dimensional) or as nanodroplets. The dynamics under such conditions have been a much discussed and central topic in the focus of intense worldwide research activities within the last two decades. The present book discusses how the resulting molecular mobility is influenced by the subtle counterbalance between surface effects (typically slowing down molecular dynamics through attractive guest/host interactions) and confinement effects (typically increasing the mobility). It also explains how these influences can be modified and tuned, e.g. through appropriate surface coatings, film thicknesses or pore diameters. "Dynamics in Confinement" sums up the present state-of-the-art and introduces to the analytical methods of choice for the study of dynamics in nanometer-scale confinement.
Author: Zheng Qian Xuan Publisher: Trans Tech Publications Ltd ISBN: 3038265705 Category : Technology & Engineering Languages : en Pages : 120
Book Description
The conference covers the newest knowledge and progressive trends in the field of ecology and new building materials and products. Both scientific and practical knowledge in the field of civil engineering industry and related topics are presented.
Author: Publisher: ScholarlyEditions ISBN: 1464927162 Category : Science Languages : en Pages : 134
Book Description
Benzylidene Compounds: Advances in Research and Application: 2011 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Benzylidene Compounds. The editors have built Benzylidene Compounds: Advances in Research and Application: 2011 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Benzylidene Compounds in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Benzylidene Compounds: Advances in Research and Application: 2011 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.
Author: P Chen Publisher: Taylor & Francis US ISBN: 9781855739284 Category : Science Languages : en Pages : 712
Book Description
This book combines three fundamental areas of interest to the science and engineering community, these being material science, nanotechnology and molecular engineering. Although there have been various results published in this field, there has yet to be a fully comprehensive review. This book covers key research on molecular mechanisms and thermodynamic behaviour of (bio)polymer surfaces and interfaces, from theoretical and experimental perspectives.
Author: Chad Daley
Author: Chad Daley
Author: Yue Zhang
Author: Nikhil Padhye
Author: Connie B. Roth
Author: Yu Chai
Author: Toshiji Kanaya
Author: Friedrich Kremer
Author: Zheng Qian Xuan
Author: 
Author: P Chen