表面活性剂水溶液中芘的激基缔合物形成

Pyrene Excimer Formation in Aqueous Solution of Surfactants

在离子型和非离子型表面活性剂水溶液中观察到了芘的激基缔合物荧光,其荧光强度与单体荧光强度比值对表面活性剂浓度的关系曲线中有一峰值.指出表面活性剂单体分子在水溶液中呈绕曲状构型,对应上述峰值的表面活性剂浓度为其临界胶束浓度.

Pyrene was used as a fluorescent probe to determine the molecular conformation ofsurfactants (ionic and non-ionic) in aqueous solution.The fluorescence emission frompyrene excimer was observed to be dependent on the concentration of surfactants.Amaximum was noted in the curve of the ratio of fluorescence intensity of pyreneexcimer to that of monomer versus the concentration of surfactant and theconcentration corresponding to this maximum was proved to be the cmc of thesurfactant.The monomer molecule of surfactants in aqueous solution was supposed to beself-coiling which is due to the hydrophobic interaction and in a dynamic equilibrium.The characteristics of the pyrene excimer formation in an aqueous solution of surfactantprovided a feasible method for the determination of cmc of surfactant.