Detection of phase transitions in liquid crystals on a water surface by a Maxwell displacement current‐measuring technique
Detection of phase transitions in liquid crystals on a water surface by a Maxwell displacement current‐measuring technique
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通过麦克斯韦位移电流测量技术检测水面液晶的相变
DOI：
10.1063/1.468804
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发表时间：
1995
影响因子：
4.4
通讯作者：
M. Muhamad
中科院分区：
文献类型：
--
作者：
M. Iwamoto;T. Kubota;M. Muhamad
采用麦克斯韦位移电流（MDC）测量技术研究了4-氰基-4 '-5-烷基联苯（5CB）、4-氰基-4'-7-烷基联苯（7 CB）、4-氰基-4 '-8-烷基联苯（8 CB）和4-氰基-4'-10-烷基联苯（10 CB）液晶分子的朗缪尔薄膜的相变。LC分子取向从各向同性相到极性相的弱一级相变通过借助于该技术在不可测量的低表面压力范围内压缩膜而被清楚地检测到。为了进一步压缩，检测到液晶膜的稳定单层相和稳定三层相之间的一级相变。结果表明，MDC测量技术在整个分子区域范围内检测相变是有用的。
The phase transitions of Langmuir films of liquid‐crystal 4‐cyano‐4’‐5‐alkyl‐biphenyl (5CB), 4‐cyano‐4’‐7‐alkyl‐biphenyl (7CB), 4‐cyano‐4’‐8‐alkyl‐biphenyl (8CB), and 4‐cyano‐4’‐10‐ alkyl‐biphenyl (10CB) were investigated by a Maxwell displacement current (MDC)‐measuring technique. A weak first‐order phase transition of the orientation of LC molecules from the isotropic phase to the polar one was clearly detected by compressing the film in the range of immeasurably low surface pressure by means of the technique. For further compression, a first‐order phase transition between a stable monolayer phase and a stable three‐layer phase of the liquid crystal film was detected. The result shows that the MDC‐measuring technique is useful in the detection of phase transitions over the entire range of molecule areas.