Polymer Dynamics as a Mechanism of Cartilage Flow independent Viscoelasticity

  • Filename: polymer-dynamics-as-a-mechanism-of-cartilage-flow-independent-viscoelasticity.
  • ISBN: 9780549493785
  • Release Date: 2007
  • Number of pages: 218
  • Author:
  • Publisher: ProQuest

Articular cartilage is the soft tissue consisting mostly of extracellular matrix biopolymers and water that covers the ends of bones in synovial joints. Cartilage functions mechanically: it provides low-friction surfaces for articulation and deforms during joint contact to decrease contact pressure and increase joint stability. As such, understanding the specific molecular origins of cartilage resistance to deformation is necessary to understand cartilage mechanical function.

The Mesoscopic Theory of Polymer Dynamics

  • Filename: the-mesoscopic-theory-of-polymer-dynamics.
  • ISBN: 9048122317
  • Release Date: 2009-12-16
  • Number of pages: 256
  • Author: Vladimir N. Pokrovskii
  • Publisher: Springer Science & Business Media

The theory presented in this book explains in a consistent manner all dynamics effects observed in very concentrated solutions and melts of linear polymers from a macromolecular point of view. The presentation is compact and self-contained.

Relaxation Dynamics of Branched Polymers

  • Filename: relaxation-dynamics-of-branched-polymers.
  • ISBN: 9780549431039
  • Release Date: 2007
  • Number of pages: 127
  • Author:
  • Publisher: ProQuest

The tube dilation model for star and comb polymers was investigated in detail and predictions compared to rheological data from polypropylene, polybutadiene and polystyrene comb polymers along with PEP star polymers. The relaxation time from the Tube Dilation Model was compared with the classical Tube Model and was shown to have an extra power dependence on the fraction of the comb backbone.

The Theory of Polymer Dynamics

  • Filename: the-theory-of-polymer-dynamics.
  • ISBN: 0198520336
  • Release Date: 1988
  • Number of pages: 391
  • Author: Masao Doi
  • Publisher: Oxford University Press

'This book is destined to join the classics of polymer science...an essential purchase for any serious student of polymer dynamics.' British Polymer Journal

Polymer and Cell Dynamics

  • Filename: polymer-and-cell-dynamics.
  • ISBN: 3764369248
  • Release Date: 2003-08-25
  • Number of pages: 290
  • Author: Wolfgang Alt
  • Publisher: Springer Science & Business Media

Polymer and cell dynamics play an important role in processes like tumor growth, metastasis, embryogenesis, immune reactions and regeneration. Based on an international workshop on numerical simulations of polymer and cell dynamics in Bad Honnef (Germany) in 2000, this volume provides an overview of the relevant mathematical and numerical methods, their applications and limits. Polymer and Cell Dynamics will be of interest to scientists and advanced undergraduates.

Polymer Dynamics in Dilute Media

  • Filename: polymer-dynamics-in-dilute-media.
  • ISBN: STANFORD:hj553gv4999
  • Release Date: 2011
  • Number of pages:
  • Author:
  • Publisher: Stanford University

Polymers undergo a sharp coil to stretch conformational transition in extension dominated flows when the strain rate exceeds a critical value. Dramatic change in flow behavior is known to occur at the coil-stretch transition, making it useful for several commercial applications. Despite decades of study, this phenomenon remains surrounded with controversy as the effect of solvent properties and fluid flow elements on this transition is not fully understood. In this work, we present a study of the coil-stretch transition and related hysteresis phenomenon using stochastic computer simulations. We first investigate the effect of solvent quality on the coil-stretch transition using Brownian dynamics simulations. Unlike experiments, which are plagued with problems related to polydispersity of polymers and inaccurate control over flow profiles, simulations offer a powerful platform to systematically study the effect of solvent quality while keeping all other parameters in the system constant. The system consists of a polymer subjected to planar elongational flow in both theta solvents and good solvents. The polymer is represented by a bead-spring chain model undergoing elongational flow. Solvent-mediated effects such as fluctuating hydrodynamic interactions (HI) and excluded volume (EV) are included rigorously. Conformational hysteresis is understood in terms of a 1-D energy landscape theory with an activation energy barrier for transition. At steady state, depending upon the flow rate, the energy landscape can either have one or two energy wells. An energy landscape with one well corresponds to the coiled state at low flow rate and stretched state at high flowrate. The double welled landscape corresponds to the hysteretic regime where both coiled and stretched conformational states coexist across the ensemble population. A key factor in determining the effect of solvent quality is the use of a proper measure of solvent quality. In almost all earlier studies, the effect of molecular weight on solvent quality has been neglected, producing inconsistent results. Here, the solvent quality is quantified carefully such that the effect of molecular weight and temperature is taken into account. Contrary to earlier findings, it is observed that with improvement in solvent quality, the chains unravel faster and the critical strain rate at which the coil to stretch transition takes place decreases. Furthermore, the solvent quality has a profound effect on the scaling of the critical strain rate with molecular weight and on both the transient and steady state properties of the system. Universal functions are shown to exist for the observed dynamic and static properties, which will prove useful in determining the operating parameters for experiments. In particular, the ratio of the two different relaxation times (longest relaxation time and zero shear rate viscosity) is found to be a universal function of solvent quality independent of molecular weight. The relaxation times (both the longest relaxation time and the zero shear rate viscosity) increase while the critical strain rate is found to decrease with solvent quality. Next, the study of conformational hysteresis is extended to more complicated 3-D flows to understand the effect of flow vorticity on this phenomenon. Heretofore, there has been no systematic methodology for studying the dynamical interactions between polymer molecules and elementary flow patterns in three-dimensional flows. Such a framework is essential not just for gaining valuable insights into the physics of complex fluids at a fundamental level, but it is also crucial for various important applications like turbulent drag reduction where the underlying physical mechanisms involve dynamical interactions between polymers and turbulence fine scale flow features. Such a study is presented here to provide a framework to interpret complex fluid phenomenon in terms of elementary flow patterns. We investigate the conformational

Principles of Soft Matter Dynamics

  • Filename: principles-of-soft-matter-dynamics.
  • ISBN: 9789400755369
  • Release Date: 2012-12-30
  • Number of pages: 656
  • Author: Rainer Kimmich
  • Publisher: Springer Science & Business Media

Practical applications of soft-matter dynamics are of vital importance in material science, chemical engineering, biophysics and biotechnology, food processing, plastic industry, micro- and nano-system technology, and other technologies based on non-crystalline and non-glassy materials. Principles of Soft-Matter Dynamics. Basic Theories, Non-invasive Methods, Mesoscopic Aspects covers fundamental dynamic phenomena such as diffusion, relaxation, fluid dynamics, normal modes, order fluctuations, adsorption and wetting processes. It also elucidates the applications of the principles and of the methods referring to polymers, liquid crystals and other mesophases, membranes, amphiphilic systems, networks, and porous media including multiphase and multi-component materials, colloids, fine-particles, and emulsions. The book presents all formalisms, examines the basic concepts needed for applications of soft-matter science, and reviews non-invasive experimental techniques such as the multi-faceted realm of NMR methods, neutron and light quasi-elastic scattering, mechanical relaxation and dielectric broadband spectroscopy which are treated and compared on a common and consistent foundation. The standard concepts of dynamics in fluids, polymers, liquid crystals, colloids and adsorbates are comprehensively derived in a step-by-step manner. Principles and analogies common to diverse application fields are elucidated and theoretical and experimental aspects are supplemented by computational-physics considerations. Principles of Soft-Matter Dynamics. Basic Theories, Non-invasive Methods, Mesoscopic Aspects appeals to graduate and PhD students, post-docs, researchers, and industrial scientists alike.

Self Healing Polymers

  • Filename: self-healing-polymers.
  • ISBN: 9783527670208
  • Release Date: 2013-03-29
  • Number of pages: 450
  • Author: Wolfgang H. Binder
  • Publisher: John Wiley & Sons

Self-healing is a well-known phenomenon in nature: a broken bone merges after some time and if skin is damaged, the wound will stop bleeding and heals again. This concept can be mimicked in order to create polymeric materials with the ability to regenerate after they have suffered degradation or wear. Already realized applications are used in aerospace engineering, and current research in this fascinating field shows how different self-healing mechanisms proven successful by nature can be adapted to produce even more versatile materials. The book combines the knowledge of an international panel of experts in the field and provides the reader with chemical and physical concepts for self-healing polymers, including aspects of biomimetic processes of healing in nature. It shows how to design self-healing polymers and explains the dynamics in these systems. Different self-healing concepts such as encapsulated systems and supramolecular systems are detailed. Chapters on analysis and friction detection in self-healing polymers and on applications round off the book.

Phenomenology of Polymer Solution Dynamics

  • Filename: phenomenology-of-polymer-solution-dynamics.
  • ISBN: 9781139504515
  • Release Date: 2011-10-06
  • Number of pages:
  • Author: George D. J. Phillies
  • Publisher: Cambridge University Press

Presenting a completely new approach to examining how polymers move in non-dilute solution, this book focuses on experimental facts, not theoretical speculations, and concentrates on polymer solutions, not dilute solutions or polymer melts. From centrifugation and solvent dynamics to viscosity and diffusion, experimental measurements and their quantitative representations are the core of the discussion. The book reveals several experiments never before recognized as revealing polymer solution properties. A novel approach to relaxation phenomena accurately describes viscoelasticity and dielectric relaxation and how they depend on polymer size and concentration. Ideal for graduate students and researchers interested in the properties of polymer solutions, the book covers real measurements on practical systems, including the very latest results. Every significant experimental method is presented in considerable detail, giving unprecedented coverage of polymers in solution.

Effects of Nanoscale Confinement and Interfaces on the Structural Relaxation of Amorphous Polymers Monitored at the Molecular Scale by Fluorescence and Dielectric Spectroscopy

  • Filename: effects-of-nanoscale-confinement-and-interfaces-on-the-structural-relaxation-of-amorphous-polymers-monitored-at-the-molecular-scale-by-fluorescence-and-dielectric-spectroscopy.
  • ISBN: 9780549507734
  • Release Date: 2008
  • Number of pages: 249
  • Author:
  • Publisher: ProQuest

In summary, this work investigated confinement and interfacial effects on the relaxation dynamics of polymer at the glass transition (T g), above the glass transition (alpha-relaxation dynamics), and below the glass transition (physical aging).

DMCA - Contact