Thelocal relaxations of polymers in cylindrical confinement are measured experimentally using QENS. When polystyrene is confined in cylindrical nanopores, the segmental relaxations slow down non-monotonically with pore size. This trend is also observed for EISF, which measured the fraction of non-diffusing hydrogen within the probing time scale of QENS. At last, we found that when d/R ee > 2, hydrogen has the lowest MSD. When the pore size is decreasing to 2 > d/Ree > 1, MSD is slightly higher but still lower than that for bulk PS. When the pore size is further decrease to d/Ree
Polymers are essential to biology because they can have enough stable degrees of freedom to store the molecular code of heredity and to express the sequences needed to manufacture new molecules. Through these they perform or control virtually every function in life. Although some biopolymers are created and spend their entire career in the relatively large free space inside cells or organelles, many biopolymers must migrate through a narrow passageway to get to their targeted destination. This suggests the questions: How does confining a polymer affect its behavior and function? What does that tell us about the interactions between the monomers that comprise the polymer and the molecules that confine it? Can we design and build devices that mimic the functions of these nanoscale systems? The NATO Advanced Research Workshop brought together for four days in Bikal, Hungary over forty experts in experimental and theoretical biophysics, molecular biology, biophysical chemistry, and biochemistry interested in these questions. Their papers collected in this book provide insight on biological processes involving confinement and form a basis for new biotechnological applications using polymers. In his paper Edmund DiMarzio asks: What is so special about polymers? Why are polymers so prevalent in living things? The chemist says the reason is that a protein made of N amino acids can have any of 20 different kinds at each position along the chain, resulting in 20 N different polymers, and that the complexity of life lies in this variety.
Efforts to understand the effect of confinement on the glass transition of an unentangled polymer melt in the field of coarse-grained simulations have focused on the use of free-standing and supported films with atomistically smooth substrates. The effects these types of nano-confinement have produced are of great value when trying to understand the interfacial effects on the structure and dynamics of the material that can dominate many properties at very small length scales (
From artificial surfaces to living cells, Molecular Nano Dynamics, Vol. I and Vol. II explores more than 40 important methods for dynamic observation of the nanoscale. Edited by absolute science greats from Japan, this two-volume set covers all important aspects of this topic: nanoscale spectroscopy and characterization tools, nanostructure dynamics, single living cell dynamics, active surfaces, and single crystals. Destined to be the definitive reference work on nanoscale molecular dynamics and their observation for years to come, this is a must-have reference for chemists, physicists, physical chemists, theoretical chemists, and materials scientists.
This first book on this important and emerging topic presents an overview of the very latest results obtained in single-chain polymer nanoparticles obtained by folding synthetic single polymer chains, painting a complete picture from synthesis via characterization to everyday applications. The initial chapters describe the synthetics methods as well as the molecular simulation of these nanoparticles, while subsequent chapters discuss the analytical techniques that are applied to characterize them, including size and structural characterization as well as scattering techniques. The final chapters are then devoted to the practical applications in nanomedicine, sensing, catalysis and several other uses, concluding with a look at the future for such nanoparticles. Essential reading for polymer and materials scientists, materials engineers, biochemists as well as environmental chemists.
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.
Porous materials are of scientific and technological importance because of the presence of voids of controllable dimensions at the atomic, molecular, and nanometer scales, enabling them to discriminate and interact with molecules and clusters. Interestingly the big deal about this class of materials is about the “nothingness” within — the pore space. International Union of Pure and Applied Chemistry (IUPAC) classifies porous materials into three categories — micropores of less than 2 nm in diameter, mesopores between 2 and 50 nm, and macropores of greater than 50 nm. In this book, nanoporous materials are defined as those porous materials with pore diameters less than 100 nm.Over the last decade, there has been an ever increasing interest and research effort in the synthesis, characterization, functionalization, molecular modeling and design of nanoporous materials. The main challenges in research include the fundamental understanding of structure-property relations and tailor-design of nanostructures for specific properties and applications. Research efforts in this field have been driven by the rapid growing emerging applications such as biosensor, drug delivery, gas separation, energy storage and fuel cell technology, nanocatalysis and photonics. These applications offer exciting new opportunities for scientists to develop new strategies and techniques for the synthesis and applications of these materials.This book provides a series of systematic reviews of the recent developments in nanoporous materials. It covers the following topics: (1) synthesis, processing, characterization and property evaluation; (2) functionalization by physical and/or chemical treatments; (3) experimental and computational studies on fundamental properties, such as catalytic effects, transport and adsorption, molecular sieving and biosorption; (4) applications, including photonic devices, catalysis, environmental pollution control, biological molecules separation and isolation, sensors, membranes, hydrogen and energy storage, etc./a
Both an introductory course to broadband dielectric spectroscopy and a monograph describing recent dielectric contributions to current topics, this book is the first to cover the topic and has been hotly awaited by the scientific community.
Advanced Characterization of Nanostructured Materials — Probing the Structure and Dynamics with Synchrotron X-Rays and Neutrons is a collection of chapters which review the characterization of the structure and internal dynamics of a wide variety of nanostructured materials using various synchrotron X-ray and neutron scattering techniques. It is intended for graduate students and researchers who might be interested in learning about and applying these methods. The authors are well-known practitioners in their fields of research who provide detailed and authoritative accounts of how these techniques have been applied to study systems ranging from thin films and monolayers on solid surfaces and at liquid-air, liquid-liquid and solid-liquid interfaces; nanostructured composite materials; battery materials, and catalytic materials. While there have been a great many books published on nanoscience, there are relatively few that have discussed in one volume detailed synchrotron X-ray and neutron methods for advanced characterization of nanomaterials in thin films, composite materials, catalytic and battery materials and at interfaces. This book should provide an incentive and a reference for researchers in nanomaterials for using these techniques as a powerful way to characterize their samples. It should also help to popularize the use of synchrotron and neutron facilities by the nanoscience community.
