Dynamics of Liquid Crystals by means of Deuterium NMR relaxation

(del libro): 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

Risonanza Magnetica Nucleare. Principi e Applicazioni

La Risonanza Magnetica Nucleare (NMR) è una tecnica spettroscopica diventata ormai fondamentale per vasto campo di studi che spazia dalla Chimica, alla Biologia Molecolare, alla Medicina col progressivo diffondersi della MRI (Risonanza Magnetica per Immagini). Da qui l'esigenza di scrivere un testo che introduca i principi di funzionamento dell'NMR, dando spazio a una descrizione sia qualitativa che quantitativa dei fenomeni alla base di questa spettroscopia, ponendo specialmente l'accento sulla natura fisica e molecolare dei parametri estraibili dall'analisi spettrale. Inoltre, dato l'enorme contributo dell'NMR alle scienze dei materiali, il libro si propone di fornire tutti gli elementi per l'approfondimento di alcune delle tecniche NMR più usate e delle recenti applicazioni sia nel campo dei materiali "soffici" che dei solidi. Un capitolo finale è dedicato ad illustrare i principi di base ed alcune applicazioni della MRI

Applications of solid-state NMR to the study of organic/inorganic multicomponent materials

The characterization of a variety of organic/inorganic multicomponent ma- terials (OIMM) through solid-state NMR (SSNMR) spectroscopy will be reviewed. Many examples of applications to OIMM will be described, based on the observation of different nuclei and the use of various SSNMR methods, such as 1D and 2D techniques, measurements on relaxation and spin diffusion processes. OIMM are a very general category of systems differing, for example, by chemical nature and relative amount of organic and inorganic components, shape and size of the domains, and type of organic- inorganic interface. Some of the most investigated classes of OIMM are organically modified silicates, polymer/clay composites, polymer/inorganic filler systems, polymer electrolytes, stationary chromatographic phases, zeolites, and mesoporous silicas in- cluding small organic molecules. The aspects most efficiently investigated by SSNMR and discussed in this review include physical and/or chemical interactions occurring at the organic-inorganic interface, structural and dynamic behavior of the organic compo- nents, and dimensions and dispersion of organic and inorganic domains

Synthesis of deuterium-labelled, optically active, ferroelectric liquid crystals

The synthesis of two selectively deuterium-labelled 4-(((S)-1-((S)-1-((S)-2-methylbutoxy)-1-oxopropan-2-yloxy)-1-oxopropan-2-yloxy)carbonyl)phenyl 4'-(heptyloxy)biphenyl-4-carboxylate derivatives is reported. A new preparation strategy was developed in order to optimise the yields as well as the optical purity, this property being of fundamental importance for the optical applications of this ferroelectric liquid crystal. (C) 2010 Elsevier Ltd. All rights reserved

Translational Self-Diffusion in the Synclinic to Anticlinic Phases of a Ferroelectric Liquid Crystal

In this work, the first direct measurement of inter and intra-layer molecular self-diffusion in the smectic phases of a chiral smectogen (S)-2-methylbutyl-[4'-(4 ''-heptyloxyphenyl)-benzoyl-4-oxy-(S)-2-((S)-2')benzoyl)-propionyl)]-propionate (ZLL7/*) by means of pulsed field gradient NMR is reported. Self-diffusion coefficients as low as 10(-13) m(2) s(-1) have been measured by combining magic echo spin decoupling with a stimulated echo sequence. The transitions among synclinic-anticlinic smectic phases are associated with a change in the self-diffusion coefficients