A series of cationic surfactants of allyl alkyldimethylammonium bromide (AAnDB), where n=12, 16, 18, were synthesized, and the adsorption behavior of AAnDB at the air–water interface and the aggregation morphology in bulk solution were reported. The critical micelle concentration (CMC) was determined by the drop volume technique and steady state fluorescence. The surface excess concentration of AAnDB surfactants was calculated from the surface tension versus log concentration curves by applying the Gibbs' adsorption isotherm. The values of surface area per molecule calculated by using Gibbs' equation were 2.9–1.4 nm2, indicating the relatively large size of the AAnDB surfactants. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) measurements reveal that, at low surfactant concentration of allyl dodecyl dimethylammonium bromide (AA12DB) above CMC, vesicles can be spontaneously formed. However, with increasing surfactant concentration, vesicles tend to be transformed into rod‐like micelles.
This work was supported by the National Natural Science Foundation of China (Grant Nos. 70171055, 50179011), the National Natural Foundation for Distinguished Young Scholars (Grant No. 50225926), the Doctoral Foundation of Ministry of Education of China (20020532017), the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institutions of MOE, P.R.C. (TRAPOYT) in 2000 and the National 863 High Technology Research Program of China (Grant Nos. 2001AA644020, 2003AA644010).