Memory of silica aggregates dispersed in smectic liquid crystals:: Effect of the interface properties
Memory of silica aggregates dispersed in smectic liquid crystals:: Effect of the interface properties
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DOI：
10.1007/s100510050880
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发表时间：
1999-08-01
影响因子：
1.6
通讯作者：
Rosta, L
中科院分区：
文献类型：
--
作者：
Jákli, A;Almásy, L;Rosta, L
先前对含有二氧化硅颗粒的向列相液晶的研究表明，可能是由于单个二氧化硅颗粒之间的氢键作用而产生了记忆效应。我们制备了含有具有不同表面性质的二氧化硅颗粒的近晶相液晶分散体。利用中子散射技术，我们研究了界面表面效应对二氧化硅聚集体结构以及近晶层取向的影响。我们的观察结果表明，记忆的稳定性与二氧化硅表面的羟基数量相关。这些观察结果意味着，通过对二氧化硅表面羟基含量的微调，可以设计出各种类型的存储器件。我们考虑了三种能够记忆液晶取向的不同效应。对倾斜的近晶C相的测量表明，只有在反复的加热 - 冷却循环之后，随着聚集体平均尺寸的减小，表面效应才变得重要。
Previous studies on nematic liquid crystals containing silica particles indicated memory effects that might be due to hydrogen bonds between the individual silica particles. We made smectic liquid crystal dispersions containing silica particles with various surface properties. Using a neutron scattering technique we studied the interfacial surface effects on the structure of the silica aggregates, and on the smectic layer alignment. Our observations indicate that the stability of the memory correlates to the number of OH groups on the silica surfaces. The observations imply that. with fine-tuning of the OH content of the silica surfaces, various types of memory devices can be designed. We considered three different effects that can memorise the alignment of the liquid crystal. Measurements on tilted SmC phases indicate that surface effects become important only after repeated heating-cooling cycles, as the average size of the aggregates decrease.