Download or read book NMR of Liquid Crystal Dendrimers written by Carlos Rodrigues da Cruz and published by CRC Press. This book was released on 2016-12-08 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dendrimers are hyperbranched molecules with well-defined nanometer-scale dimensions. Important technological applications of these systems, both in biomedicine and materials science, have been recently proposed. Liquid crystal dendrimers are fascinating materials that combine the characteristics of dendrimers with the anisotropic physical behaviour and molecular self-organization typical of liquid crystals. This unique association of physical and chemical properties, together with the possibility of multi-selective functionalization put forward by dendrimers, opens new perspectives for applications. Nuclear magnetic resonance (NMR) is a powerful experimental technique applied in materials science and an important tool to the study of molecular organization and dynamics. This book presents an introduction to dendrimers properties with special insight into liquid crystal dendrimers and a detailed description of the NMR theory and experimental techniques used in the investigation of these materials. It also discusses recent NMR research results on liquid crystal dendrimers, with emphasis on molecular order and dynamics studies. This book introduces the properties of dendrimers, with special insight into liquid crystal dendrimers, and a detailed description of NMR theory and experimental techniques used in the investigation of these materials. It also discusses results of recent NMR research on liquid crystal dendrimers, with an emphasis on molecular order and dynamics studies. Advanced undergraduate and graduate students of physics, chemistry, and materials science and researchers in the fields of dendrimers, liquid crystals, and NMR will find the book extremely useful.
Download or read book NMR of Liquid Crystal Dendrimers written by Carlos Rodrigues da Cruz and published by CRC Press. This book was released on 2016-12-08 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dendrimers are hyperbranched molecules with well-defined nanometer-scale dimensions. Important technological applications of these systems, both in biomedicine and materials science, have been recently proposed. Liquid crystal dendrimers are fascinating materials that combine the characteristics of dendrimers with the anisotropic physical behaviour and molecular self-organization typical of liquid crystals. This unique association of physical and chemical properties, together with the possibility of multi-selective functionalization put forward by dendrimers, opens new perspectives for applications. Nuclear magnetic resonance (NMR) is a powerful experimental technique applied in materials science and an important tool to the study of molecular organization and dynamics. This book presents an introduction to dendrimers properties with special insight into liquid crystal dendrimers and a detailed description of the NMR theory and experimental techniques used in the investigation of these materials. It also discusses recent NMR research results on liquid crystal dendrimers, with emphasis on molecular order and dynamics studies. This book introduces the properties of dendrimers, with special insight into liquid crystal dendrimers, and a detailed description of NMR theory and experimental techniques used in the investigation of these materials. It also discusses results of recent NMR research on liquid crystal dendrimers, with an emphasis on molecular order and dynamics studies. Advanced undergraduate and graduate students of physics, chemistry, and materials science and researchers in the fields of dendrimers, liquid crystals, and NMR will find the book extremely useful.
Download or read book Nuclear Magnetic Resonance Spectroscopy of Liquid Crystals written by Ronald Y. Dong and published by World Scientific. This book was released on 2010 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: This edited volume provides an extensive overview of how nuclear magnetic resonance can be an indispensable tool to investigate molecular ordering, phase structure, and dynamics in complex anisotropic phases formed by liquid crystalline materials. The chapters, written by prominent scientists in their field of expertise, provide a state-of-the-art scene of developments in liquid crystal research. The fantastic assortment of shape anisotropy in organic molecules leads to The discoveries of interesting new soft materials made at a rapid rate which not only inject impetus to address the fundamental physical and chemical phenomena, but also the potential applications in memory, sensor and display devices. The review volume also covers topics ranging from solute studies of molecules in nematics and biologically ordered fluids to theoretical approaches in treating elastic and viscous properties of liquid crystals. This volume is aimed at graduate students, novices and experts alike, and provides an excellent reference material for readers interested in the liquid crystal research. it is, indeed, a reference book for every science library to have.
Download or read book Nuclear Magnetic Resonance of Liquid Crystals written by Ronald Y. Dong and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Intended for researchers and students in physics, chemistry and materials science, this book provides the necessary background information and sufficient mathematical and physical detail to study the current research literature. The book begins with a survey of liquid crystal phases and field effects, together with an introduction to the basic physics of nuclear magnetic resonance. It then discusses orientational ordering and molecular field theories for various liquid crystal molecules and nmr studies of uniaxial and biaxial phases. Subsequent chapters consider spin relaxation processes and rotational, translational, and internal molecular dynamics of liquid crystals. The final chapter discusses two-dimensional and multiple- quantum nmr spectroscopies and their application in elucidating liquid crystal properties. This second edition, updated throughout, incorporates many new references and includes new mathematical appendices.
Download or read book NMR Spectroscopy Using Liquid Crystal Solvents written by JW Emsley and published by Elsevier. This book was released on 2018-01-10 with total page 385 pages. Available in PDF, EPUB and Kindle. Book excerpt: NMR Spectroscopy using Liquid Crystal Solvents covers the importance of using a liquid crystal solvent in NMR to derive nuclear dipolar spin-spin coupling constants. This book is composed of ten chapters, and begins with a brief description of the features and benefits of liquid crystal in NMR spectroscopic analysis. The succeeding chapters deal with the mode of operation of nuclear spin Hamiltonian for partially oriented molecules and the analysis of NMR spectra of partially oriented molecules, as well as the determination of rigid molecule structure. These topics are followed by discussions on internal motion studies, NMR spectra from quadpolar nuclei, and the anisotropy in nuclear spin-spin coupling. The final chapters review the theoretical and experimental studies on the anisotropy in chemical shifts, nematic rotation, and the nuclear magnetic double resonance. This book will prove useful to analytical chemists.
Download or read book Thermotropic Liquid Crystals written by Ayyalusamy Ramamoorthy and published by Springer Science & Business Media. This book was released on 2007-05-06 with total page 331 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers developments in the field of thermotropic liquid crystals and their functional importance. It also presents advances related to different sub-areas pertinent to this interdisciplinary area of research. This text brings together research from synthetic scientists and spectroscopists and attempts to bridge the gaps between these areas. New physical techniques that are powerful in characterizing these materials are discussed.
Download or read book Nuclear Magnetic Resonance of Liquid Crystals written by J.W. Emsley and published by Springer. This book was released on 1984-11-30 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: The liquid crystalline state has been known for about a century and has been studied by many techniques. Nuclear magnetic resonance has been used to study mesophases for thirty years, but it has been in very recent years that advances in this form of spectroscopy have led to a rapid growth in its applications to the study both of liquid crystals and of solutes dissolved in them. It has become apparent that no other method of studying liquid crystals can yield such a wealth of data and it is unrivalled as a means of probing the behaviour of the molecules in mesophases. There has also been a steady increase in the study of the shape of small molecules dissolved in liquid crystals via the analysis of their NMR spectrum. In fact, the study of solutes was until recently regarded as a separate activity to the study of liquid crystals themselves, but this artificial division arose only from the gap between the large amount of information that could be derived from the spectrum of a small molecule and the rather meagre data set obtainable from the spectra of liquid crystals. This gap has, however, narrowed and it is now possible to derive a very detailed picture of the structure and orientational ordering of the large molecules typical of those which form liquid crystals. There has also been a rapid growth of interest in the liquid crystalline state.
Download or read book Liquid Crystalline Dendrimers 1 Synthesis of Five Generations of Carbosilane Liquid Crystalline Dendrimers with Terminal Cyanobiphenyl Groups written by V. Shibaev and published by . This book was released on 1998 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: Using the controlled layer by layer experimental technique via reiterative sequence of chemical reactions carbosilane LC dendrimers with terminal cyanobiphenyl mesogenic groups of generations 1 - 5 were synthesized. Molecular structure and purity of all new compounds were characterized by 1H-NMR spectroscopy and GPC analysis. Thermal behavior of LC dendrimers was investigated by means of polarizing optical microscopy and DSC methods. All LC dendrimers synthesized have mesophases of smectic types over wide temperature region. Values of glass transition temperatures of LC dendrimers do not depend on generation number, but isotropisation temperature raises with increasing of generation number of LC dendrimers. LC dendrimer of generation 5 bearing 128 cyanobiphenyl mesogenic groups displays unusual type of structural polymorphism, which is under investigation.
Download or read book NMR of Ordered Liquids written by E.E. Burnell and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 465 pages. Available in PDF, EPUB and Kindle. Book excerpt: NMR of Ordered Liquids gives a unique overview of the scope and limitations of the NMR of oriented liquids, based on contributions from acknowledged experts in the field. The book consists of four sections: -detailed general introduction which covers the basic principles and sophisticated experimental techniques; -wide variety of applications ranging from NMR studies of small atoms and molecules in anisotropic liquids to the utilization of residual dipolar couplings for structure determination of biological molecules; -summary of the sophisticated theoretical treatments, computer simulations, and phenomenological models for anisotropic intermolecular interactions that are widely used in the analysis of experimental results; -overview of the dynamical aspects and relaxation processes relevant for orientationally ordered molecules.
Download or read book NMR in Liquid Crystalline Solvents written by Jakob Bulthuis and published by . This book was released on 1974 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Magnetic Resonance Spectroscopy of Liquid Crystals written by Ronald Y. Dong and published by World Scientific. This book was released on 2010 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: This edited volume provides an extensive overview of how nuclear magnetic resonance can be an indispensable tool to investigate molecular ordering, phase structure, and dynamics in complex anisotropic phases formed by liquid crystalline materials. The chapters, written by prominent scientists in their field of expertise, provide a state-of-the-art scene of developments in liquid crystal research. The fantastic assortment of shape anisotropy in organic molecules leads to the discoveries of interesting new soft materials made at a rapid rate which not only inject impetus to address the fundamental physical and chemical phenomena, but also the potential applications in memory, sensor and display devices. The review volume also covers topics ranging from solute studies of molecules in nematics and biologically ordered fluids to theoretical approaches in treating elastic and viscous properties of liquid crystals. This volume is aimed at graduate students, novices and experts alike, and provides an excellent reference material for readers interested in the liquid crystal research. It is, indeed, a reference book for every science library to have. Sample Chapter(s). Chapter 1: Novel Strategies for Solving Highly Complex NMR Spectra of Solutes in Liquid Crystals (1,464 KB). Contents: Novel Strategies for Solving Highly Complex NMR Spectra of Solutes in Liquid Crystals (E E Burnell et al.); Analytical Potentials of Natural Abundance Deuterium NMR Spectroscopy in Achiral Thermotropics and Polypeptide Chiral Oriented Solvents (P Lesot & C Aroulande); Noble Gas Probes in NMR Studies of Liquid Crystals (J Jokisaari); Bicelles OCo A Much Needed Magic Wand to Study Membrane Proteins by NMR Spectroscopy (R Soong et al.); Advances in Proton NMR Relaxometry in Thermotropic Liquid Crystals (P J Sebastiuo et al.); Deuterium NMR Study of Magnetic Field Distortions in Ferroelectric Mesogens (R Y Dong); Deuteron NMR Study of the Effects of Random Quenched Disorder in 12CB Silica Dispersions (D Finotello & V Pandya); Dynamics of Liquid Crystals by Means of Deuterium NMR Relaxation (C A Veracini & V Domenici); Translational Self-Diffusion Measurements in Thermotropics by Means of Statistic Field Gradients NMR Diffusometry (M Cifelli); Deuterium NMR Studies of Static and Dynamic Director Alignment for Low Molar Mass Nematics (A Sugimura & G R Luckhurst); Viscoelastic Properties of Liquid Crystals: Statistical-Mechanical Approaches and Molecular Dynamics Simulations (A V Zakharov); Carbon-13 NMR Studies of Thermotropic Liquid Crystals (R Y Dong); A Combined DFT and Carbon-13 NMR Study of a Biaxial Bent-Core Mesogen (A Marini et al.). Readership: Chemists, physicists and material scientists. In particular, NMR spectroscopists.
Download or read book Annual Reports on NMR Spectroscopy written by and published by Academic Press. This book was released on 2016-01-09 with total page 391 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annual Reports on NMR Spectroscopy provides a thorough and in-depth accounting of the progress made in nuclear magnetic resonance (NMR) spectroscopy and its many applications. Nuclear magnetic resonance (NMR) is an analytical tool used by chemists and physicists to study the structure and dynamics of molecules. In recent years, no other technique has gained as much significance as NMR spectroscopy. It is used in all branches of science in which precise structural determination is required, and in which the nature of interactions and reactions in solution is being studied. Annual Reports on NMR Spectroscopy has established itself as a premier resource for both specialists and non-specialists alike who want to become familiar with the new techniques and applications of NMR spectroscopy. - Serves as the premier resource for learning the new techniques and applications of NMR spectroscopy - Provides a key reference for chemists and physicists using NMR spectroscopy to study the structure and dynamics of molecules
Download or read book Dendrimers written by Claudia Maria Simonescu and published by BoD – Books on Demand. This book was released on 2018-04-25 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dendrimers are defined as nanoscale macromolecules having a particular architecture consisting of treelike arms or branches. They are characterized by special properties that make them promising candidates in medicine, biology, materials science, synthetic organic chemistry, biotechnology, environmental engineering, optics, electronics, catalysis, electrochemistry, photochemistry, and sensors and even for production of cosmetics and personal care products. The dendrimers research field is growing day by day, and scientists are exploring new synthesis and functionalization methods in order to improve and to determine new properties and thus new applications. The main purpose of this book is to highlight the issues regarding properties and applications of dendrimers in the field of biology, medicine, liquid crystal devices, electronics, quantum devices, and self-healing technology.
Download or read book Carbon 13 NMR Studies of Liquid Crystals written by and published by . This book was released on 1975 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: High resolution, proton decoupled 13C nmr are observed for a series of neat nematic liquid crystals, the p-alkoxyazoxybenzenes, and a smectic-A liquid crystal, diethylazoxydibenzoate in a magnetic field of 23 kG. The (uniaxial) order parameters S = P2(cos[theta]) are found to be about 0.4 and 0.9 for the nematic and smectic-A phase respectively at the clearing points. The order parameter increases with decreasing temperature in the nematic phase but is constant, or nearly so, with temperature in the smectic-A phase. In the nematic series studied, the ordering exhibits an even-odd alternation along the series and qualitative agreement with a recent theory due to Marcelja is found. In both phases, the spectra show that the molecule rotates rapidly about its long axis. Tentative conclusions about molecular conformational motion and 14N spin relaxation are presented for both nematic and smectic-A phases. In the smectic-A phase, the sample is rotated about an axis perpendicular to H0 and the resulting spectra are discussed. The theory of observed chemical shifts in liquid crystals is treated in an appendix. Equations are derived which relate the nmr spectra of liquid-crystals to the order parameters. A model for the smectic-C phase due to Luz and Meiboom and Doane is described and lineshapes are determined on the basis of this model for special cases. Experiments on smectic-C liquid crystals are currently underway for comparison with the theory. Also treated in an appendix is the dependence of the order parameters on the molecular potential which give rise to the various degrees of order in the different liquid crystalline phases. To a good approximation the functional dependence of the order parameters on the molecular potential is shown to be a simple one in the limit of small tilt angle in the smectic-C phase.
Download or read book NMR and Molecular Dynamics of Small Solutes in Liquid Crystals written by Peter Rudolf Luyten and published by . This book was released on 1984 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NMR Studies of Small Molecules in Liquid Crystalline Solutions written by Hyung Jin Park and published by . This book was released on 2005 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NMR Studies of Liquid Crystals and Molecules Dissolved in Liquid Crystal Solvents written by and published by . This book was released on 1982 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes several studies in which nuclear magnetic resonance (nmr) spectroscopy has been used to probe the structure, orientation and dynamics of liquid crystal mesogens and molecules dissolved in liquid crystalline phases. In addition, a modern high field nmr spectrometer is described which has been used to perform such nmr studies. Chapter 1 introduces the quantum mechanical formalisms used throughout this thesis and briefly reviews the fundamentals of nuclear spin physics and pulsed nmr spectroscopy. First the density operator is described and a specific form for the canonical ensemble is derived. Then Clebsch-Gordon coefficients, Wigner rotation matrices, and irreducible tensor operators are reviewed. An expression for the equilibrium (Curie) magnetization is obtained and the linear response of a spin system to a strong pulsed r.f. irradiation is described. Finally, the spin interaction Hamiltonians relevant to this work are reviewed together with their truncated forms. Chapter 2 is a deuterium magnetic resonance study of two 'nom' liquid crystals which possess several low temperature mesomorphic phases. Specifically, deuterium quadrupolar echo spectroscopy is used to determine the orientation of the liquid crystal molecules in smectic phases, the changes in molecular orientation and motion that occur at smectic-smectic phase transitions, and the order of the phase transitions. For both compounds, the phase sequence is determined to be isotropic, nematic, smectic A, smectic C, smectic B{sub A}, smectic B{sub C}, and crystalline. The structure of the smectic A phase is found to be consistent with the well-known model of a two dimensional liquid in which molecules are rapidly rotating about their long axes and oriented at right angles to the plane of the layers. Molecules in the smectic C phase are found to have their long axes tilted with respect to the layer normal, and the tilt angle is temperature dependent, increasing from zero at the smectic A - smectic C transition and reaching a maximum at 9{sup o} at the smectic C - smectic B{sub A} transition. This finding contradicts the results of X-ray diffraction studies which indicate that the tilt angle is 18{sup o} and temperature independent. The smectic B{sub A} - smectic B{sub C} phase transition is observed for the first time, and is found to be first order, a result that contradicts the prediction of a mean theory by McMillian. Chapter 3 is a multiple quantum nmr study of n-hexane oriented in a nematic liquid crystal solvent. The basic three pulse multiple quantum experiment is discussed which enables the observation of transitions for which.
