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Study on New Chargeable Photoelectric Conversion Effect in Composite System of Tungstic Acid and Organic Polymer

钨酸与有机聚合物复合体系新型带电光电转换效应研究

基本信息

批准号：
09650361
负责人：
HARA Kazuhiro
金额：
$ 1.54万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

项目摘要

a.We could explain the origin of the photochromic enhancement by the additives, including the O-C-H structure, taking account of the electronegativities of oxygen, carbon and hydrogen that have the values rhof 3.4,2.6 and 2.2, respectively, In the O-C bond, the oxygen will more strongly attract the electron than the carbon. Thus, if carbon makes bonds such as O-C-H, the bond strength between the carbon and hydrogen will be much weaker than that between the oxygen and carbon. In such a case, the hydrogen may be easily released with oxidation by the photogenerated hole. On the other hand, if the carbon bonds with an alkyl group, the bond between the carbon and the alkyl group is stronger than that between the carbon and the hydrogen in the O-C-H structure since the alkyl group is an electron donor. It has also been consistently explained that ketones and carboxylic acids do not show the photochromic enhancement because they do not have hydrogen next to the O-C bond.b.We studied the properties of surface waves during the gelation process of tungstic acid and gelatin and silica gel by the time resolved surface wave measurements. The anomaly is clearly shown in the change of the wave number exponent chi(omega-kappa^2 , the values 1.5 and 1.0 indicate surface tension and elastic wave, respectively). chi of the tungstic acid was about 1.4 in the sol state and rapidly decreased to 1.0 at the gelation point. chi of gelatin was about 1.4 (same as tungstic acid) in the sol state and decreased gradually after the gelation point. On the other side, chi of silica gel remained near 1.5 after the gelation point.c.We have studied dehydration process of gels, which are improtant to use the sol-gel method, and have found that the feature of the dehydration process has been much affected by the interaction between solvent and polymer network in the gels.

A.我们可以解释包括O-C-H结构在内的添加剂的光致变色增强的原因，考虑到氧、碳和氢的电负性分别为3.4、2.6和2.2，在O-C键上，氧比碳对电子的吸引更强。因此，如果碳形成O-C-H键，碳和氢之间的键强度将比氧和碳之间的键强度弱得多。在这种情况下，氢很容易被光生空穴氧化释放。另一方面，如果碳与烷基键合，则碳与烷基之间的键强于O-C-H结构中碳与氢之间的键，因为烷基是电子供体。也一直解释说，酮和羧酸没有光致变色增强，因为它们在O-C键旁边没有氢。b.我们用时间分辨表面波测量方法研究了钨酸、明胶和硅胶在凝胶过程中的表面波特性。异常明显地表现在波数指数chi的变化上(omega-kappa^2，值1.5和1.0分别表示表面张力和弹性波)。在溶胶态时，钨酸的CHI约为1.4，在凝胶点时迅速降至1.0。明胶在溶胶态的CHI约为1.4(与钨酸相同)，达到凝胶点后逐渐降低。研究了凝胶的脱水过程，发现凝胶中的溶剂和聚合物网络之间的相互作用对凝胶的脱水过程有很大影响。