Orientational photocontrol of dye molecules assisted by polymer surfaces

在研究水溶性重氮染料在偶氮苯聚合物薄膜上的定向光控过程中，发现该二色性染料的浓水溶液呈现溶向相。本财政年度发现，非离子表面活性剂的加入改变了染料溶液的m相，产生了T_<NI>=ca.50‰的向列相织构。x射线衍射图表明，介相溶液具有两个周期结构，可能对应于堆叠染料分子之间的距离和堆叠分子组成的柱之间的距离。当将溶向相的水溶液填充在涂有偶氮苯聚合物薄膜的电池中，将薄膜暴露在线偏振光下后，染料分子的取向由光化光的电矢量决定，即使系统中含有90%以上的水，也能得到稳定的照片。进一步表明，抗哮喘药物DSCG水溶液的溶变相也以同样的方式受到光诱导排列控制。

During the course of studies on the orientational photocontrol of a water-soluble diazo-dye on thin films of azobenzene polymers, it was revealed that concentrated aqueous solutions of the dichroic dye display lyotropic phases. It was found in this fiscal year that the addition of a non-ionic surfactant modifies the M-phase of a dye solution to give rise to a nematic texture with T_<NI>=ca.50ﾟ. X-ray diffraction patterns suggested that the mesophasic solution possesses two periodical structures probably corresponding to the distance between stacked dye molecules and to that between columns consisting of stacked molecules. When the aqueous solution with lyotropic phase was filled in a cell coated with thin films of an azobenzene polymer after exposure of the films to linearly polarized light, the orientational direction of dye molecules was determined by the electric vector of actinic light to give stable photoimages even though the system contains more than 90% of water. It was shown furthermore that a lyotropic phase of an aqueous solution of an anti-asthmatic drug, DSCG,is subjected to photoinduced alignment control in the same way.