de Almeida Martins João P, Chávez Fabián Vaca, Sebastião Pedro J
Departamento de Física, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001, Lisboa, Portugal.
Magn Reson Chem. 2014 Oct;52(10):540-5. doi: 10.1002/mrc.4091. Epub 2014 Jun 28.
We investigate the effect of monoatomic salts on the molecular dynamics in the nematic and isotropic phases formed by the chromonic liquid crystal Edicol Sunset Yellow. The study was carried out using proton nuclear magnetic resonance relaxometry. To analyse the effect of incorporation of additional sodium chloride or lithium chloride on the solutions' molecular dynamics, the spin-lattice relaxation time was measured for Larmor frequencies between 10 kHz and 100 MHz. In the nematic phase, the presence of additional sodium or lithium ions seems to contribute to an increase of the rotations/reorientations corr elation times in comparison with the mixture without extra ions. The collective motions detected by proton NMR relaxometry are associated with collective fluctuations of molecules within the stacks in the nematic phase and with order parameter fluctuations in the isotropic phase.
我们研究了单原子盐对由铬酸盐液晶伊地康日落黄形成的向列相和各向同性相分子动力学的影响。该研究采用质子核磁共振弛豫测量法进行。为了分析额外添加氯化钠或氯化锂对溶液分子动力学的影响，测量了拉莫尔频率在10 kHz至100 MHz之间的自旋 - 晶格弛豫时间。在向列相中，与没有额外离子的混合物相比，额外的钠离子或锂离子的存在似乎有助于增加旋转/重取向相关时间。通过质子核磁共振弛豫测量法检测到的集体运动与向列相中堆叠内分子的集体涨落以及各向同性相中的序参量涨落有关。
