稳态荧光探针法研究槐糖脂生物表面活性剂的胶束化行为

Studies on Micelle Behaviors of Sophorolipid Biosurfactant by Steady-State Fluorescence Probe Method

应用稳态荧光探针法测定了非离子生物表面活性剂槐糖内脂临界胶束浓度(CMC)和胶束聚集数(Nagg),并考察了添加无机电解质和短链脂肪醇对槐糖内酯CMC的影响。结果表明,槐糖内酯的CMC为1.3×10-4 mol.L-1,并随加入电解质浓度的升高而略有降低,外加短链脂肪则使其CMC值升高;在4～8倍的CMC浓度范围内,槐糖内酯溶液Nagg随其浓度增大而增大,但胶束聚集数较小,为4～8个;激光纳米粒径结果显示槐糖内酯胶束动态直径较大且分布较为集中,平均约为90nm。槐糖内酯胶束具有聚集数小而直径大的特点,表明该生物表面活性剂所形成的胶束排列较为松弛。

The critical micelle concentration （CIVIC） of sophorolipid was determined by steady-state fluorescence probe method in which pyrene was used as fluorescence probe. Meanwhile, the changes in the sophorolipid CIVIC were examined in the addition of NaCl and aliphatic alcohol, respectively. The results showed that the CIVIC of sophorolipid was 1.3×10 4 mol.L-1 and had a slight decrease as NaCl concentration increased. However, the CMC of sophorolipid appeared to increase in the presence of ali-phatic alcohol. The aggregation numbers and the micelle size of sophorolipid solution were investigated by fluorescence quenching and laser light scattering method. The aggregation numbers were 4-8 with the concentrations of sophorolipid in the range of 4 -8 CIVIC and the miceIle mean diameter for sophorolipid with the concentration of 6 CIVIC was about 90 nm. These experimental results indicated that the micelle should be incompact.