Short And Long Chains At Interfaces

Epoxy resins are regarded as thermosetting resins and have found various c- mercial applications after crosslinking with adequate curing agents [1–3]. H- ever, some epoxy resins have been used as thermoplastic resins without curing agents. Figure 1 shows the applications of epoxy resins that are classi?ed to three categories: thermosets in combination with curing agents, thermoplastics wi- out curing agents, and raw materials for modi?cation. The use in thermoplastics is not popular compared with the two other applications. Typical thermoplastic applications are found in stabilizers for vinyl resins, toners for copying - chines, ?re retardants for engineering plastics, and sizing material for glass or carbon ?bers. The epoxy resin most frequently used is the oligomer of the diglycidyl ether of bisphenol-A (DGEBA) whose chemical structure is shown below [1–3]. The DGEBA is composed of linear molecules with different molecular weights according to the variation of the repeated number (n) in the structural formula.

Interface and colloid science is an important, though often under-valued, branch of science. It has applications and ramifications in domains as disparate as agriculture, mineral dressing, oil recovery, chemical industry, biotechnology, medical science, and many more. Proper application of interface and colloid science requires factual knowledge and insight into the many basic laws of physics and chemistry upon which it is based. Fundamentals of Interface and Colloid Science is the first book to cover this field in the depth neccessary to be a valuable reference and an excellent textbook.From the beginning to the end of the book, systems of growing complexity are treated gradually. The presentation is particularly suited to emphasize that interfaces are not autonomous phases. As a rule, interfacial properties can be varied only by changing the adjoining phases, so that the properties of these bulk phases must be understood first. The text also recognizes common principles behind a variety of phenomena, and helps the reader to understand them and to develop and improve processes. The systematic treatment of the material in the book makes this clear, and makes the text itself an important contribution to the field. Systematic treatment of information An excellent addition to volume I Two chapters contributed by other experts in the field Uses a deductive approach to increase the order of complexity Written by a leading expert in the field Two chapters contributed by other outstanding scientists Uses a systematic and deductive approach First comprehensive review of the topic

A complete and timely overview of the topic, this volume of the encyclopedia imparts knowledge of fundamental principles of polymer blends. Each article is uniformly structured for easy navigation, containing the latest research & development and its basic principles and applications.

Significant research has been done in polymeric nanocomposites and progress has been made in understanding nanofiller-polymer interface and interphase and their relation to nanocomposite properties. However, the information is scattered in many different publication media. This is the first book that consolidates the current knowledge on understanding, characterization and tailoring interfacial interactions between nanofillers and polymers by bringing together leading researchers and experts in this field to present their cutting edge research. Eleven chapters authored by senior subject specialists cover topics including: Thermodynamic mechanisms governing nanofiller dispersion, engineering of interphase with nanofillers Role of interphase in governing the mechanical, electrical, thermal and other functional properties of nanocomposites, characterization and modelling of the interphase Effects of crystallization on the interface, chemical and physical techniques for surface modification of nanocellulose reinforcements Electro-micromechanical and nanoindentation techniques for interface evaluation, molecular dynamics (MD) simulations to quantify filler-matrix adhesion and nanocomposite mechanical properties.

Liquid crystals, polymers and polymer liquid crystals are soft condensed matter systems of major technological and scientific interest. An understanding of the macroscopic properties of these complex systems and of their many and interesting peculiarities at the molecular level can nowadays only be attained using computer simulations and statistical mechanical theories. Both in the Liquid Crystal and Polymer fields a considerable amount of simulation work has been done in the last few years with various classes of models at different special resolutions, ranging from atomistic to molecular and coarse-grained lattice models. Each of the two fields has developed its own set of tools and specialized procedures and the book aims to provide a state of the art review of the computer simulation studies of polymers and liquid crystals. This is of great importance in view of a potential cross-fertilization between these connected areas which is particularly apparent for a number of experimental systems like, e.g. polymer liquid crystals and anisotropic gels where the different fields necessarily merge. An effort has been made to assess the possibilities of a coherent description of the themes that have developed independently, and to compare and extend the theoretical and computational techniques put forward in the different areas.

Electrophysiological tools and biologic delivery systems generally rely on non-optimal methods for gaining access through cellular membranes. Electrophysiological techniques that provide intracellular access, such as patch clamping, result in membrane holes and cell death in a matter of hours, while the delivery of bioactive materials are hampered by low bioavailability following passage through the endosomal pathways. In each case, the lipid bilayer backbone of the cellular membrane presents a formidable barrier to intracellular access. As biological gatekeepers, cell membranes not only physically define everything from whole organisms to individual organelles, they also prevent unobstructed flow of molecules between the inner and outer regions of the membrane. This occurs since the hydrophobic lipid acyl tails form a narrow hydrophobic layer a few nanometers thick, which is highly unfavorable for the passage of most hydrophilic molecules. It is this region that is one of the greatest obstacles to the dream of biotechnology seamlessly and non-destructively integrating synthetic components with biological systems. This thesis contributes to the understanding of how to rationally design devices that interact specifically with this hydrophobic region. In turn, this work begins to establish design guidelines for creating non-destructive, membrane-penetrating bio-inorganic interfaces. The beginning chapters focus on the development of the "stealth" probe platform. In nature, there exist specialized transmembrane proteins capable of incorporating into lipid bilayers by replicating the lipid hydrophilic-hydrophobic-hydrophilic structure. The stealth probe design mimics this structure by creating 2-10nm hydrophobic bands on otherwise hydrophilic structures. However, since current lithographic methods do not possess the necessary resolution, a new fabrication technique using a combination of top-down fabrication with bottom-up self-assembly methods was developed. This approach uses an evaporated chrome-gold-chrome stack and focused ion beam (FIB) milling, where the exposed edge of the embedded gold layer can be specifically functionalized with a hydrophobic thiol-mediated self-assembled monolayer. Chapter 3 explores the propensity for insertion and specific interaction of the stealth probe hydrophobic band with the hydrophobic lipid bilayer core. In order to gain quantitative insight into the interaction behavior, atomic force microscopy was used in conjunction with a new, stacked lipid bilayer testing platform. By using stacks of 100's to 1000's of lipid bilayers, substrate-probe interaction artifacts can be removed while simultaneously allowing precise determination of probe location within a lipid bilayer. It was found that completely hydrophilic probes reside in the hydrophilic hydration region between bilayers, whereas hydrophobically functionalized stealth probes preferred to reside in the bilayer core. This behavior was found to be independent of hydrophobic functionalization, with butanethiol and dodecanethiol both displaying preferential localization. The subsequent chapters explore how the molecular structure of the hydrophobic band and the band thickness affect membrane-probe interface stability. The lipid stack platform provides an easy method of force-clamp testing, which enabled quantitative extrapolation of the unstressed interface strength. A series of tests with various length alkanethiols found that the crystallinity of the molecules in the hydrophobic band is the dominant factor influencing interfacial stability. Surprisingly, hydrophobicity was found to be a secondary factor, although necessary to drive spontaneous membrane integration. Molecular length was also found to play a role in determining the ultimate interfacial strength, with short chain molecules similar in length to amino acid side chains promoting the most stable interfaces. The thickness of the hydrophobic band was found to regulate the interface structure. Bands with thicknesses comparable to that of the host lipid bilayer core likely promote a fused interface geometry, similar in structure to that of transmembrane protein-lipid bilayer interfaces. Thicker bands began to transition to a 'T-junction' interface that is characterized by a lower interface stability. Interestingly, the behavior of 10nm bands were indistinguishable from completely hydrophobic probes, reinforcing the importance of nanoscale patterning for stable membrane integration. Chapter 6 builds on the results of the previous chapters by exploring how various stealth probe geometries influence adhesion behavior. In agreement with force clamp testing, short disordered monolayers displayed strong integration into the bilayer core, while crystalline monolayers displayed extremely weak integration. Preliminary adhesion testing results with human red blood cells demonstrate that the stealth probe geometry holds promise for in vitro and in vivo platforms, expanding the results of this work from simply a biophysical test system to a real world example. Finally, the behavior of two hydrophobic bands either commensurately spaced with the hydrophobic core spacing in the bilayer stack, or incommensurately spaced in order to force one band to reside in the hydrophilic hydration layer, is explored. It was found that the commensurately spaced bands display superior strength to single band tips, which is attributed to the necessity to simultaneously rupture both membrane-hydrophobic band interfaces. Conversely, the incommensurately spaced probes display a significant destabilization of the interface. This is thought to be due to the forced residence of one hydrophobic band in a hydrophilic hydration layer. This result is intriguing for biologic delivery systems, as the nuclear double membrane presents a unique barrier geometry, and a double band system may provide a facile means for penetration.

In ten volumes, this unique handbook covers all fundamental aspects of surface and interface science and offers a comprehensive overview of this research area for scientists working in the field, as well as an introduction for newcomers. Volume 1: Concepts and Methods Volume 2: Properties of Elemental Surfaces Volume 3: Properties of Composite Surfaces: Alloys, Compounds, Semiconductors Volume 4: Solid-Solid Interfaces and Thin Films Volume 5: Solid-Gas Interfaces I Volume 6: Solid-Gas Interfaces II Volume 7: Liquid and Biological Interfaces Volume 8: Interfacial Electrochemistry Volume 9: Applications of Surface Science I Volume 10: Applications of Surface Science II Content of Volumes 7 & 8: * Probing Liquid/Solid Interfaces at the Molecular Level * Structure and Dynamics of Liquid-Solid Interfaces * Adsorption of Biomolecules * Liquid Surfaces * Surfaces of Ionic Liquids * Superhydrophobicity * Cell Penetrating Peptides Targeting and Distorting Biological Membranes * Theory of Solid/Electrolyte Interfaces * Metal/Electrolyte Interfaces: An Atomic View * X-Ray Spectroscopy at Electro-Catalytic Interfaces * Fundamental Aspects of Electro-Catalysis * Non-Linear Processes at Solid/Liquid Interfaces