一种偶氮聚电解质在不同pH值条件下的静电逐层自组装研究

研究了一种光响应偶氮聚电解质(PEAPE)在不同pH值条件下的自组装,重点讨论了pH值对静电逐层自组装以及对光响应性能的影响.研究表明,在所研究的pH范围内,pH值越低,越有利于生成吸光度高的自组装膜,对应的自组装膜厚度也越大.红外光谱分析表明,偶氮聚电解质在不同pH溶液中存在不同的电离情况.pH值越低,用于自组装的溶液中的聚合物链上的电荷数越少,链构象越卷曲.解释了不同pH值条件下自组装膜吸光度和厚度差别的原因.

pH EFFECT ON ELECTROSTATIC LAYER-BY-LAYER SELF-ASSEMBLY OF A SIDE-CHAIN AZO POLYELECTROLYTE

The effect of pH value on the electrostatic layer-by-layer selfassembly and the photoresponsive behavior of on azo polyelectrolyte Poly{2-4-(4'-ethoxyphenylazo)phenoxy]ethyl acrylate-co-acrylic acid}(PEAPE).Results show that in the studied pH value range,the lower the pH value,the higher is the UV-Vis absorbance and larger is the thickness of the multilayer films.FTIR studies indicate that the azo polyelectrolyte exhibits a different ionization degree in the solutions with different pH values.The higher absorbance and larger thickness of the layer-by-layer films can be attributed to the low ionization degree and the shrinkage conformation of PEAPE in solutions with the low pH value.FTIR analysis also confirms that the driving force for layer-by-layer self-assembly of PEAPE and poly(diallydimethyl ammoniumchloride)is the electrostatic interaction.