Effect of Crowding Agent Polyethylene Glycol on Lyotropic Chromonic Liquid Crystal Phases of Disodium Cromoglycate
Effect of Crowding Agent Polyethylene Glycol on Lyotropic Chromonic Liquid Crystal Phases of Disodium Cromoglycate
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DOI：
10.3390/cryst9030160
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发表时间：
2019-03-19
期刊：
影响因子：
2.7
通讯作者：
Lavrentovich, Oleg D.
中科院分区：
文献类型：
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作者：
Koizumi, Runa;Li, Bing-Xiang;Lavrentovich, Oleg D.
将拥挤剂如聚乙二醇（PEG）添加到由材料如色甘酸二钠（DSCG）的水分散体形成的溶致发色液晶（LCLC）中导致各向同性相和有序相的相分离。这种行为类似于DNA的纳米级凝聚，但发生在微米级。拥挤分散体中凝聚发色区域的结构尚未完全理解，特别是，不清楚凝聚域是处于非线性（N）状态还是柱状（C）状态。在这项研究中，我们报告的小角X射线散射（SAXS）和广角X射线散射（WAXS）测量的混合物的水溶液的DSCG与PEG和比较结果的测量纯DSCG的水溶液。X射线测量表明，在N相中将PEG添加到DSCG触发了与各向同性（I）相共存的C相的出现。在共存区域内，发色聚集体的柱之间的横向距离随着温度的升高而减小。
Adding crowding agents such as polyethylene glycol (PEG) to lyotropic chromonic liquid crystals (LCLCs) formed by water dispersions of materials such as disodium cromoglicate (DSCG) leads to a phase separation of the isotropic phase and the ordered phase. This behavior resembles nanoscale condensation of DNAs but occurs at the microscale. The structure of condensed chromonic regions in crowded dispersions is not yet fully understood, in particular, it is not clear whether the condensed domains are in the nematic (N) or the columnar (C) state. In this study, we report on small angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS) measurements of mixtures of aqueous solutions of DSCG with PEG and compare results to measurements of aqueous solutions of pure DSCG. X-ray measurements demonstrate that addition of PEG to DSCG in the N phase triggers appearance of the C phase that coexists with the isotropic (I) phase. Within the coexisting region, the lateral distance between the columns of the chromonic aggregates decreases as the temperature is increased.