紫外光辐照有机硅氧烷水解行为的荧光探针法监测

Hydrolysis behavior of organic siloxane under UV irradiation monitored by fluorescence probe

为揭示紫外光辐照对有机硅氧烷加速水解的作用,以芘为荧光探针,分别对紫外光照及非光照条件下3种有机硅氧烷酸水解体系进行了跟踪检测。荧光光谱对比发现:紫外光辐射条件下,在具有明显疏水性取代基硅氧烷水解缩合反应前期,出现明显且不断增长的荧光探针芘的基激缔合物特征发射峰;在具有较弱疏水性取代基硅氧烷水解缩合反应前期,出现明显且不断降低的芘单体特征发射峰;而在非光照条件下,上述相应有机硅氧烷荧光特征峰变化缓慢。结果表明,紫外光辐照不仅对有机硅氧烷水解具有明显促进作用,而且也因此引起分子簇集行为明显变化,这些作用对其溶胶-凝胶过程产生影响。

To reveal the hydrolysis of organic siloxane accelerated by UV irradiation, the hydroly- sis processes of three organic siloxanes with different substituent groups were monitored by using pyrene as a fluorescence probe. The following results were found. Compared with non UV irradi- ation system, the excimer fluorescence emission peaks of pyrene obviously increased with time for the organic siloxane with strong hydrophobic organic substituent group, the monomer fluores- cence emission peaks of pyrene remarkably decreased for the organic siloxane with weak hydro- phobic organic substituent group. The results indicated that UV irradiation could not only pro- mote the hydrolysis of organic siloxane but also cause the change in molecular aggregation. This investigation gives an insight into the effect of UV irradiation on hydrolysis of organic siloxane.