Molecular Gels: Materials with Self-Assembled Fibrillar Networks

ISBN-13: 9781402033520 / Angielski / Twarda / 2005 / 978 str.

Richard G. Weiss; Pierre Terech

Opis

"Molecular Gels: Materials with Self-Assembled Fibrillar Networks" is a comprehensive treatise on gelators, especially low molecular-mass gelators and the properties of their gels. The structures and modes of formation of the self-assembled fibrillar networks (SAFINs) that immobilize the liquid components of the gels are discussed experimentally and theoretically. The spectroscopic, rheological, and structural features of the different classes of low molecular-mass gelators are also presented. Many examples of the application of the principal analytical techniques for investigation of molecular gels (including SANS, SAXS, WAXS, UV-vis absorption, fluorescence and CD spectroscopies, scanning electron, transmission electron and optical microscopies, and molecular modeling) are presented didactically and in-depth, as are several of the theories of the stages of aggregation of individual low molecular-mass gelator molecules leading to SAFINs. Several actual and potential applications of molecular gels in disparate fields (from silicate replication of nanostructures to art conservation) are described. Special emphasis is placed on perspectives for future developments. This book is an invaluable resource for researchers and practitioners either already researching self-assembly and soft matter or new to the area. Those who will find the book useful include chemists, engineers, spectroscopists, physicists, biologists, theoreticians, and materials scientists.

Spis treści

Introduction.- Theory: Theory Of Molecular Association And Thermoreversible Gelation: Thermodynamic theory of network-forming liquid mixtures. Some important examples of non-gelling associating mixtures. Gelling solutions and mixtures. Summary.- Growth And Chirality Amplification In Helical Supramolecular Polymers: Introduction. Helical aggregation. Discotics. Linear self-assembly. A two-state model. Aggregate ends. Chirality amplification. Sergeants and soldiers. Conclusions and outlook.- Self Assembling Peptide Gels: Theoretical model of self-assembling chiral rod-like units. Experiments illustrating predictions of the model. Stabilization by twist. Nematic fluids and gels. Properties for new materials.- Kinetics Of Nucleation, Aggregation And Aging: Introduction. Some basic thermodynamic concepts. Basic concepts of the theory of nucleation and cluster growth. Spinodal decomposition. Secondary aggregation, coarsening and aging. Discussion.- Soft Glassy Rheology: Introduction. Rheology. The SGR model. Rheological aging: imposed strain. Rheological aging: imposed stress. Discussion and conclusion.- Rheological Chaos In Wormlike Micelles And Nematic Hydronamic: Deterministic Chaos in viscoelastic materials in shear flow. Spatiotemporal rheological oscillations and chaotic dynamics.- Wetting of Fibres: Introduction. The Rayleigh-Plateau instability. Drop shapes. Heterogeneous fibers. Invasion of a network of fibers. Conclusion.- Techniques: Gel Formation: Phase Diagrams Using Tabletop Rheology And Calorimetry: Introduction. Detecting the sol-gel transition by tabletop theology. Thermodynamics of gelation: sol-gel transition by calorimetry. Conclusions and perspectives.- Direct-Imaging And Freeze-Fracture Cryo-Transmission Electron Microscopy Of Molecular Gels: Introduction. Cryo-TEM. Cryo-Tem Investigations of Molecular Gels. Future Developments.- Molecular Gels And Small-Angle Scattering: Foreword. Introduction. Basic principles. Form-factors of rod-like scatterers. Semi-rigid fibers. Fibers with anisometric sections. Tubes. Helices. Scattering by the junction zones in the networks. Structure factor peak in poorly organized fibrillar scatterers. Oriented fibers. Real space data. Kinetic studies. Useful hints for a standard SANS investigation of molecular gels. Conclusion.- X-Ray Diffraction Of Poorly Organized Systems And Molecular Gels: Introduction Long range ordering. Single crystal diffraction. X-rays and neutrons. Applications of diffraction.- Optical Spectroscopic Methods As A Tool To Investigate Gel Structures: Introduction. Electronic absorption and emission spectroscopy. Ifrared spectroscopy.- Circular Dichroism For Studying Gel-Like Phases: Introduction. Technique. Applications to the study of gel-like phases. Perspectives.- Systems - Organogels: Low Molecular Mass Organo-Gelators: Analyses of the natures of gelators and liquids for efficient gelation: Introduction. Classification of low molecular-mass organo-gelators (lmogs). The role of liquid in gelation by lmogs. Future directions.- Design And Functions Of Low Molecular Weight Gelators Bearing Sugars And Steroids In Their Backbone: Introduction. Steroid derivatives for gelating organic liquids. Sugar derivatives for gelating liquids. Other related lmogs. Outlook.- Safin Gels With Amphiphilic Molecules: Introduction. Amphiphilic molecules. Gels with amphiphilic molecules. Gemini amphiphilic molecules. Conclusions.- Hydrogels: Advances In Molecular Hydrogels: Introduction. Historical perspective. Amino acid derivatives and oligopeptide based hydrogelators- b -Peptides as hydrogelators.Carbohydrate based hydrogelator

O autorze

Richard G. Weiss is Professor of Chemistry, Department of Chemistry, Georgetown University, Washington, DC, USA.

Pierre Terech is Research Director, CNRS – Atomic Energy Center – Grenoble University, Grenoble, France.

Blurb

Molecular gels and fibrillar networks – a comprehensive guide to experiment and theory

Molecular Gels: Materials with Self-Assembled Fibrillar Networks provides a comprehensive treatise on gelators, especially low molecular-mass gelators (LMOGs), and the properties of their gels. The structures and modes of formation of the self-assembled fibrillar networks (SAFINs) that immobilize the liquid components of the gels are discussed experimentally and theoretically. The spectroscopic, rheological, and structural features of the different classes of LMOGs are also presented. Many examples of the application of the principal analytical techniques for investigation of molecular gels (including SANS, SAXS, WAXS, UV-vis absorption, fluorescence and CD spectroscopies, scanning electron, transmission electron and optical microscopies, and molecular modeling) are presented didactically and in-depth, as are several of the theories of the stages of aggregation of individual LMOG molecules leading to SAFINs. Several actual and potential applications of molecular gels in disparate fields (from silicate replication of nanostructures to art conservation) are described. Special emphasis is placed on perspectives for future developments.

This book is an invaluable resource for researchers and practitioners either already researching self-assembly and soft matter or new to the area. Those who will find the book useful include chemists, engineers, spectroscopists, physicists, biologists, theoreticians, and materials scientists.

Richard G. Weiss is Professor of Chemistry, Department of Chemistry, Georgetown University, Washington, DC, USA.

Pierre Terech is Research Director, CNRS – Atomic Energy Center – Grenoble University, Grenoble, France.