稳态荧光探针法研究对-烷基-苄基聚氧乙烯醚羧酸甜菜碱的聚集行为

The Study of Aggregation Properties of p-(n-Alkyl)-benzyl Polyoxyethylene Ether Carboxybetaine by Steady-State Fluorescence

利用荧光探针法和表面张力法测定了一类疏水基中含有苯基的新型甜菜碱两性离子表面活性剂对-烷基-苄基聚氧乙烯醚羧酸甜菜碱(ABECB)的临界胶团浓度(cmc)、胶团微极性和表面张力(γcmc).研究结果表明,荧光探针(芘)法可用来测定这类表面活性剂的临界胶团浓度(cmc),且测定结果与表面张力法(吊片法)接近;ABECB具有较低的cmc和γcmc值,表明此类表面活性剂具有优良的表面活性;胶团的微极性随着疏水链长的增大而略微减小,氧乙烯(EO)单元数的增大对ABECB胶团核内的微极性影响不明显.

The values of cmc, micelle micropolarity and γcmc of p-（n-alkyl）-benzyl polyoxyethy- lene ether carboxybetaine （ABECB） have been measured by fluorescence and Wilhelmy-plate method. It indicated that probe （pyrene） fluorescence emission spectra method could be used to determine the critical micelle concentration （cmc） of p-（n-alkyl）-benzyl polyoxyethylene ether carboxybetaine, and the results are compatible with that of Wilhelmy-plate method. The values of cmc and γcmc show that these surfactants have high surface activity. The micellar micropolarity was observed to decrease, as the change of carbon atom number of the substituted hydrophobic chain of benzene ring, while the effect of increasing polyoxyethylene number on micellar micropolarity is little.