Ultrasonically surface modified polyethersulfone members and method of making thereof

A method for mechanically treating the surface of a microporous polymeric membrane, comprising:

• i. (i) Immersing a microporous polymeric membrane in a liquid;
• ii. (ii) Applying ultrasonic waves to the microporous polymeric membrane immersed in the liquid;
• Wherein the ultrasonic waves are applied in a dose in the range of from 0.1 W/cm2 to 10 W/cm2;
• Wherein said method comprises increasing the surface porosity of the membrane such that the amount of pores in the surface of the membrane is increased, and/or the size of the pores is increased to obtain a microporous polymeric membrane having a modified surface;
• Wherein said microporous membrane comprises a first surface, a second surface, and an intermediate wall;
• and
• Wherein said microporous membrane comprises a separation layer wherein said separation layer is located within the wall disposed between the first surface and the second surface, the separation layer not affected by the ultrasonic waves.