الابحاث

​In this work, the movement of the interface of two immiscible liquids in a capillary is investigated by the model simulation based on the Capillary Pressure-Poiseuille flow approach. The movement of immiscible liquids that occurs in the pores of ultrafiltration and microfiltration membranes during the membrane formation, characterization, and filtration has not been discussed in detail until now, since the radius and length of the pores in such membranes are limited to a range of micrometers or less. Particularly, no investigation has been made on the interfacial pressure profile along the pore length. This work attempts to give the answers to those questions. The conclusions drawn from the results of the simulation are as follows. When the interface between two immiscible liquids moves from the pore entrance to the pore exit, the relationship given by the Lucas-Washburn equation, i.e. “The distance of the interface from the pore entrance is proportional to square root of time, t”, seems valid when the viscosity of displacing liquid is higher than the wetting liquid (i.e. the liquid with which the pore is initially filled). The distance versus t plot becomes concave upward, otherwise. The contact angle of the displacing liquid should be more than 90o to avoid pore expansion or contraction. Otherwise, pore expansion may occur at the pore entrance and contraction at the pore exit. In an extreme case, the displacing liquid may evaporate at the pore exit. Also, the presence of large membrane pores does not affect the interfacial movement in small membrane pores.

https://www.researchgate.net/publication/364108246_Modeling_of_the_movement_of_two_immiscible_liquids_in_membrane_pores​