Study of Micelle Formation by Fluorocarbon Surfactant N-(2-hydroxypropyl)perfluorooctane Amide in Aqueous Solution

Abstract

Micelles formed by fluorocarbon surfactant N-(2-hydroxypropyl)perfluorooctane amide in aqueous solution were studied through surface tension, dynamic light scatting (DLS), isothermal titration calorimetry (ITC), and dissipative particle dynamic (DPD) simulations. Through surface tension measurements, the effectiveness of surface tension reduction, the maximum surface excess concentration, and the minimum area occupied per surfactant molecule at the air/water interface were investigated. The critical micelle concentration (cmc) at different temperatures and a series of thermodynamic parameters (ΔG(m)0, ΔH(m)0, ΔS(m)0, ΔG(ads)0, ΔH(m)(A) and ΔC(p(m))0) of micellization were evaluated. The thermodynamic parameters showed that the micelle formation was entropy-driven. The micelle formation was also confirmed by ITC and DLS. In addition, the DPD simulations were conducted to simulate the whole process of micelle formation to make micelle formation better understood.