红外光谱法研究重氮树脂自组装膜的光化学反应

Monitoring of the Photo Reaction of Self-Assembly Film Based on Diazoresin by FTIR

将具有导电功能的聚(4-羧酸钠苯基)乙炔阴离子(PCPA)与具有生物活性的DNA聚阴离子交替与重氮树脂聚阳离子(DR)进行自组装,可以得到层重复单元为DR/DNA/DR/PCPA的三夹层聚电解质自组装膜。重氮树脂聚阳离子在紫外光照射下可与聚阴离子发生光化学反应,使层与层之间的离子键连接转化为共价键连接,从而制备稳定的纳米级超薄膜。本文用红外光谱法对此类聚电解质自组装膜的光化学反应过程进行了研究。

A novel trilayer multilayer film was alternatively assembled from photosensitive diazoresin (DR) as polycation, bioactive DNA and electric-active poly(4-carboxyphenyl)acetylene (PCPA) as polyanions, respectively, in aqueous solution via electrostatic attraction. The experimental results revealed that the absorbance of PCPA/DR/DNA film at 383nm increases linearly with increasing of assembled trilayers, which indicates that a progressive assembly runs regularly with almost equal amount of deposition in each cycle. Under UV irradiation, the diazonium group of DR was decomposed and then the covalent bonds formed between layers instead of ionic bonds. The stability of the film increases obviously toward strong electrolyte solutions. The photodecomposition of self-assembly film was studied by FTIR.