Spreading Process And Experimental Research On Surfactant Drop

Spreading phenomenon is induced when a surfactant liquid drop is placed over a solid surface or a prewetted liquid film. The process is applied to foods, petrochemical, agriculture, biological medicine and other fields widely. Therefore, research on hydrodynamics, colloid chemistry, interface science and etc in the spreading process has great significance. This paper analyzes and researches the subject in two aspects: experimental research and numerical simulation. In experimental aspect, referencing the foreign experience and promoting, experimental device that can meet experimental requirements is constructed by high speed camera, ultrasonic cleaner and etc, by which, process data of different cmc and species of surfactant drop on different thickness of liquid film. Furthermore, spreading exponent, the maximum spreading radium, the time of maximum radium, onset time and other spreading characteristic value are analyzed by the methods of logarithm fitting, linear fitting and nonlinear fitting; In numerical simulation aspect, two dimensional nonlinear controlling equations including thickness of liquid film, concentration of single molecule and micelles in surface of prewetted liquid film, internal solutions and solid surface (seven equations model) is established by mean of the average cross section methods. Then the process of time-space evolution including thickness of liquid film, concentration of single molecule and micelles are simulated using the program of PDECOL and MATLAB. Effect of the mass of surfactant M, polymerization numbers N, distribution coefficients, difficult soluble coefficient and other parameter on spreading process and other spreading characterizes are analyzed.