Mechanism underlying influence of temperature on oil-water-solid contact-line movement
Temperature can considerably affect the movement of the three-phase contact line.Investigating the microscopic motion and temperature influence mechanism of the contact line plays a pivotal role in further examination of the oil-water flow at the nanoscale.In this paper,a molecular dynamics model of a n-decane-water-silica contact line was established.The influence of temperature on the movement of the contact line was studied based on the mechanism of the contact-line movement,molecular jump distance,and molecular frequency.The results show that the oil-water-solid contact line exhibits"flipping""plug"and"shear"movements under different wettability conditions,resulting in the different trends of the contact-line speed to change from gradually increasing to becoming stable,from gradually decreasing to becoming stable,tending to be 0.Temperature does not change the above motion mechanism and law.An increase in molecular energy and a decrease in adsorption density result in an increase in molecular displacement frequency between adsorption sites.Additionally,the increase in molecular displacement frequency under the"plug"mechanism is considerably greater than that under the"flipping"mechanism.Thus,the temperature-promoting effects on the movement of the three-phase contact line on a medium-wettability surface are greater than those on a hydrophilic surface.Moreover,temperature has a minor effect on the mean distance of the molecular jump,and an increase in molecular displacement frequency caused by the increasing temperature is the primary reason behind the acceleration of the contact-line movement.
万方数据
维普
