Dong Nuclear Magnetic Resonance of Liquid Crystals

Erscheinungsjahr 2012
ISBN: 978-1-4684-0208-7
Verlag: Springer US
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 260 Seiten, eBook

Reihe: Partially Ordered Systems

Liquid crystals have become ubiquitous in the displays for electronic devices, ranging from wrist watches to laptop computers. Nuclear magnetic resonance is one of the important mechanisms for determining their structures tures and properties. This book covers NMR techniques used in studying liquid crystals and present up to date results from such studies. Ronald Dong has worked on NMR in liquid crystals for much of his professional career. Topics covered include: Nuclear spin dynamics, orientational order, molecular field theories of liquid-crystal molecules, nuclear spin relaxation, spin relaxation, rotational and translational dynamics, internal dynamics of liquid-crystal molecules, NMR in liquid crystals; an appendix covers rotations, Euler angles and Wigner rotation matrices.

Zielgruppe

Research

Autoren/Hrsg.

Dong, Ronald Y.

Inhaltsverzeichnis

1 Introduction to Liquid Crystals.- 1.1 Classification of Mesophases.- 1.2 Effects of External Fields.- 1.3 Polymorphism in Liquid Crystals.- References.- 2 The Dynamics of Nuclear Spins.- 2.1 The Density Matrix.- 2.2 The Nuclear Spin Hamiltonian.- 2.3 Motional Averaging.- 2.4 Pulsed Magnetic Resonance.- References.- 3 Orientational Order.- 3.1 Macroscopic Description of Order Parameters.- 3.2 The Orientational Distribution Function.- 3.3 Molecular Theories of Uniaxial Phases.- 3.4 NMR in Biaxial Mesophases.- 3.5 NMR in Uniaxial Phases.- References.- 4 Molecular Field Theories of Flexible Nematogens.- 4.1 The Additive Potential Method.- 4.2 The Thermodynamic Properties.- 4.3 Survey of Other Methods.- 5 Nuclear Spin Relaxation Theory.- 5.1 The Master Equation of Relaxation.- 5.2 The Bloch-Wangsness-Redfield Theory.- 5.3 Relaxation of One I=1 Spin.- 5.4 Relaxation in Multispin Systems.- References.- 6 Director Fluctuations and Spin Relaxation.- 6.1 Relaxation Processes.- 6.2 Director Fluctuations.- 6.3 Nematic Order Fluctuations.- References.- 7 Rotational and Translational Dynamics.- 7.1 Molecular Reorientation as a Stochastic Process.- 7.2 Small Step Rotational Diffusion and Strong Collision Models.- 7.4 Translational Diffusion in Liquid Crystals.- References.- 8 Internal Dynamics of Flexible Mesogens.- 8.1 Models of Internal Motions.- 8.2 Superimposed Rotations Model.- 8.3 Spin Relaxation by Correlated Internal Motions.- 8.4 Comparison with Experiments.- References.- 9 Multiple-Quantum and Two-Dimensional NMR.- 9.1 Two-Dimensional NMR Spectroscopy.- 9.2 Multiple-Quantum NMR.- References.- Appendix A. Rotations, Euler Angles, and Wigner Rotation Matrices.