UV ABSORPTION-SPECTRA OF AZOBENZENE-CONTAINING LONG-CHAIN FATTY-ACIDS AND THEIR BARIUM SALTS IN SPREAD MONOLAYERS AND LANGMUIR-BLODGETT FILMS
UV ABSORPTION-SPECTRA OF AZOBENZENE-CONTAINING LONG-CHAIN FATTY-ACIDS AND THEIR BARIUM SALTS IN SPREAD MONOLAYERS AND LANGMUIR-BLODGETT FILMS
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DOI：
10.1021/la00090a020
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发表时间：
1989-11-01
期刊：
影响因子：
3.9
通讯作者：
TAKENAKA, T
中科院分区：
文献类型：
--
作者：
KAWAI, T;UMEMURA, J;TAKENAKA, T
同时记录了含偶氮苯的长链脂肪酸及其钡盐在水面上的扩散单分子膜的表面压力和紫外光吸收光谱。结合偶氮苯发色团的相变和聚集态的变化，讨论了在压缩过程中观察到的光谱变化。具有8碳烷基链的酸及其钡盐表现出从液晶相(流体相)到凝胶相(二维晶相)的相变，比表面积减小。然而，具有12碳烷基链的化合物在所考察的整个表面积上都处于凝胶相。在凝胶阶段，所有的化合物都形成一个聚集体。此外，还测量了沉积在石英板上的Langmuir-Blodgett膜的紫外吸收光谱，并与水面上铺展的单分子膜的吸收光谱进行了比较。
Surface pressures and UV absorptionspectra of spread monolayers of azobenzene-containing long-chain fatty acids and their barium salts on the water surfacehave been simultaneously recorded as a function of surface area. The observed spectral changes upon compression have been discussed in con-nection with phase transitions and changes in theaggregation state of the azobenzene chromophores. Acids and their barium salts with an 8-carbon alkyl chain exhibit the phase transition from the liquid crystalline (fluid) to gel (two-dimensional-crystalline) phases with decreasing surface area. The com-pounds with a 12-carbon alkyl chain, however, are in the gel phase throughout the whole surface area examined. In the gel phase, all compounds form an-aggregate. In addition, UV absorption spectra of Langmuir-Blodgett films deposited on quartz plates have been measured and compared with those of the spread monolayers on the water surface.