4-二氰乙烯基-N,N-二甲基苯胺与不同表面活性剂的相互作用

The Interaction Between 4-Dicyanovinyl-N,N-dimethylaniline with Surfactants

用光谱法研究了荧光分子4-二氰乙烯基-N,N-二甲基苯胺(DCVA)与十二烷基硫酸钠(SDS)、聚氧乙烯(23)月桂醚(BRIJ35)、十二烷基三甲溴化铵(DTAB)胶束间的相互作用.与在水中相比,在上述3类表面活性剂溶液中探针的荧光强度分别增加到3.3、5.4和5.1倍;最大发射波长随表面活性剂浓度的增加分别蓝移了5、11和9nm.由此可知,DCVA在DTAB和BRIJ35胶束中所处微环境的极性相似,而在SDS胶束中DCVA所处微环境的极性较大.通过DCVA在3种表面活性剂溶液中的荧光强度,计算出了DCVA与其胶束的结合常数分别为1.7×103、1.4×103和8.8×102.

Since 4-dicyanovinyl-N, N-dimethylaniline （DCVA） is a prototype class of organic donoracceptor compound, which is sensitive to microenvironmental properties such as polarity, viscosity and hydrogen bonding capacity. Interactions of DCVA with sodium dodecylsulphate （SDS）, dodecyltrimethylammonium bromide （DTAB） , and polyoxythylene （23） laurylether （BRIJ35） have been investigated by measuring the fluorescent spectra of DCVA in aqueous solutions of varying concentrations surfactants. The fluorescent intensities of DCVA are enhanced approximately 5. 1-fold, 5.4-fold,and 3.3-fold by DTAB, BRIJ 35 ,and SDS micelles compared with that in aqueous solution, as well as the emission maximum wavelengths of DCVA blue-shift 5, ll,and 9 nm, respectively. In addition, according to the emission maximum wavelengths of DCVA in micelles, the microenvironment polarities of binding sites of DCVA in DTAB and BRIJ 35 micelles are similar, but that of DCVA in SDS micelle is obviously higher. The binding constants are calculated by the fluo- rescence intensities of DCVA in the three kinds of micelles to be 1.7 ×10^3, 1.4 ×10^3, and 8.8×10^2, respectively.