一种新型偶氮聚电解质的光致取向行为研究

1992年Decher等报道了聚电解质的静电逐层自组装技术，即将带有相反电荷的两种聚电解质通过交替沉积的方式，在固体介质表面上形成均匀的厚度可控的多层膜。利用此方法可方便地对膜结构进行设计和调控，从原理上讲，可制备任意成分多层复合的新材料。该技术以其操作简易，结构可控等特点已成为近10年功能高分子纳米薄膜领域的研究热点。

LAYER-BY-LAYER SELF-ASSEMBLY AND PHOTO-INDUCED DICHROISM OF A NOVEL SIDE-CHAIN AZO POLYELECTROLYTE

A novel polyelectrolyte PNANT functionalized with electron donor-acceptor type azobenzene chromophores has been synthesized through post-polymerization azo coupling reaction and characterized by 1H-NMR,FTIR and UV-Vis spectroscopy.The degree of functionalization (DF) of PNANT was 20% measured by elemental analysis.The degree of polymerization and its distribution were determined by GPC to be X n=251 with a polydispersion index 1.53.A glass transition temperature of 119℃ was observed from DSC thermogram. H-aggregation of azo chromophores of PNANT in spin-coated film and self-assembled film were detected from UV-Vis spectra,and the degree of H-aggregation of PNANT in the self-assembled film was found to be higher than that in the spin-coated film.Dichroism was optically induced in the spin-coated film and self-assembled film upon the irradiation of a polarized Ar + laser beam at 488 nm.The orientational order parameter obtained was 0.15 for spin-coated film and 0.07 for the self-assembled film.The resulting dichroism detected by UV-Vis spectra exhibited long-term stability.