摘要
采用D2O的2HNMR线型和弛豫分析了PEOPPOPEO/D2O/对二甲苯体系的层状和六角液晶相的动力学行为.通过实验测得了两个不同体系的自旋晶格弛豫时间T1、自旋自旋弛豫时间T2和2HNMR谱.2HNMR谱均为具有四极劈裂的粉末谱线型,且在谱图的中心,βLD=54.7°时存在一个倒峰.倒峰的出现直接表明引起体系中弛豫的主要动力学过程处于极窄化区域.采用NMR弛豫模型,通过调节动力学参数,使理论模拟的2HNMR谱、弛豫时间、倒峰的大小与实验的对应量相吻合,求得了体系的动力学参数.
The dynamic behaviors of the lamellar and hexagonal liquid crystalline phases of PEO-PPO-PEO/D2O/p-xylene composite were studied by ^2H NMR spectroscopy,^2H powder spectra and ^2H spin-lattice and spin-spin relaxation times were measured in two samples with different compositions. All spectra showed powder lineshape with quadrupole splitting and a reversed peak at the center when βLD = 54. 7°, indicating that the dominant dynamic process that modulates the quadrupole interaction is in the extreme narrowing region, Dynamic parameters of the studied systems were obtained by fitting the experimentally measured ^2H spectra, spin-lattice and spin-spin relaxation times and the intensity of the reversed peak to a theoretical NMR relaxation model.
出处
《波谱学杂志》
CAS
CSCD
北大核心
2005年第3期253-259,共7页
Chinese Journal of Magnetic Resonance
基金
国家自然科学基金资助项目(20474034
20374031
20373029
20274020)
教育部南开大学
天津大学科技合作基金资助项目.
