Lyotropic liquid crystalline phases formed by Gemini surfactants in an ionic liquid

doi:10.16085/j.issn.1000-6613.2015.12.036

Abstract

Abstract: The lyotropic liquid crystals formed by Gemini surfactants in ethyl ammonium nitrate (EAN) were investigated by differential scanning calorimetry(DSC),X ray diffractometer(XRD),polarizing microscope(POM) equipped with a hot stage and FTIR. All the surfactants form smectic A phase(SmA) in liquid crystalline region. The EAN molecules mainly exist in the polar sublayers of liquid crystals. The temperature ranges of liquid crystal phase increase with increasing Gemini surfactant alkyl chain length while show maximum with the increase of spacer length. The hydroxyl groups decrease the interactions between the ionic head groups and counterions. The temperature range of liquid crystal state is thus narrowed.

Key words: lyotropic liquid crystal, Gemini surfactants, ionic liquids, self-assembly

摘要： 通过差示扫描量热仪(DSC)、X射线衍射仪(XRD)、热台偏光显微镜(POM)和红外光谱仪等手段研究了Gemini表面活性剂在硝酸乙基铵(EAN)中构筑的溶致液晶体系(lyotropic liquid crystal,LLc)的性质。结果表明,在液晶区内,所形成的溶致液晶均为层状介晶A相(SmA),且EAN主要存在于液晶相分子层的极性亚层中;液晶相稳定存在的温度区间随Gemini表面活性剂的浓度、尾链长度的增加而变大,随联接链的增加表现出先增大再减小的趋势;羟基削弱了离子头基与反离子间的相互作用,进而缩小了液晶相稳定存在的温度区间。

关键词: 溶致液晶, Gemini型表面活性剂, 离子液体, 自组织

CLC Number:

TQ423.9

SONG Binglei, CHEN Tao, TIAN Jinnian, PEI Xiaomei, MENG Li. Lyotropic liquid crystalline phases formed by Gemini surfactants in an ionic liquid[J]. Chemical Industry and Engineering Progree, 2015, 34(12): 4348-4355.

宋冰蕾, 陈涛, 田金年, 裴晓梅, 孟丽. Gemini型表面活性剂在离子液体中构筑的溶致液晶[J]. 化工进展, 2015, 34(12): 4348-4355.

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