Synthesis and Aggregation Properties of Alkyl Dibenzyl Ether Quaternary Ammonium in Aqueous Solution

A series of cation gemini surfactants with dibenzyl ether spacer(10-B-10,12-B-12,14-B-14) were synthesized from 1-bromoalkane,N,N-dimethylethanolamine and α,α'-dibromo-p-xylene.Their structures were identified by FTIR,1HNMR and ESI-MS.The aggregation number of micelle of these surfactants was determined by steady-state fluorescence method.The results show that the CMC determined by steady-state fluorescence method was in agreement with that determined by surface tension method.The critical micelle concentration(CMC) decreased from 3.24 mmol/L to 0.056 mmol/L with the alkyl chain length increasing from 10 to 14.The critical aggregation number was 6.98(10-B-10),3.87(12-B-12) and 1.62(14-B-14).The salt-induced vesicle to micelle transition was found in the aqueous solution of these surfactants as detected by dynamic light scattering(DLS).