Example：10.1021/acsami.1c06204 or Chem. Rev., 2007, 107, 2411-2502
Experimental study and molecular simulation on aggregation behavior of surface-active ionic liquids containing saturated nitrogen heterocycles in aqueous solution Journal of Surfactants and Detergents (IF1.902), Pub Date : 2021-11-03, DOI: 10.1002/jsde.12558 Mingwei Gao, Xu Guo, Peng Liu, Mingwei Zhao, Hui Yin, Caili Dai
The aggregation behavior of N-decyl-N-methylmorpholinium bromide (DMMB) in aqueous solutions was systematically investigated by experimental measurements and molecular simulation, including surface tension, electrical conductivity, fluorescence measurement, 1H NMR and dissipative particle dynamic (DPD) simulation. The critical micelle concentration (cmc) of DMMB which was obtained by different techniques showed a pretty good agreement. From the surface tension measurements, a series of surface adsorption properties such as surface tension at the cmc (γcmc), effectiveness of surface tension reduction (∏cmc), maximum surface excess concentration (Γmax), minimum surface area per molecule (Amin), were determined. The cmc values and a variety of thermodynamic parameters (, and ) of micellization in the temperature range of 25–45°C were obtained via electrical conductivity experiments. In the investigated temperature range, the thermodynamic parameters reveal that micelle formation is entropy-driven. Furthermore, micelle aggregation number (Nagg) of DMMB was calculated through the fluorescence measurement. Analysis of the 1H NMR spectrum indicates the micelle formation mechanism. The DPD simulation reflects the process of micro-phase separation. From the simulation results, at concentrations higher than cmc, spherical micelles can be formed. The investigation of DMMB micelles may help us gain a better understanding about surfactant micellization process and expand the range of potential application in materials science.