Ultrasonically surface modified polyethersulfone members and method of making thereof
The present disclosure provides a method for treating the surface of a microporous polymeric membrane, comprising immersing a microporous polymeric membrane in a liquid; and applying ultrasonic waves to the microporous polymeric membrane immersed in the liquid.
1 . 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/cm 2 to 10 W/cm 2 ;
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.
2 . The method according to claim 1 , wherein the liquid is selected from organic liquids and/or water.
3 . The method according to claim 1 , wherein the polymeric membrane is selected from polymeric sulfone membranes, polyethylene membranes, polypropylene membranes, polyamide membranes, polyvinylidene difluoride membranes and polyacrylonitrile membranes.
4 . The method according to claim 1 , wherein the microporous polymeric membrane comprises a first surface, a second surface and an intermediate wall having a wall thickness disposed between the first surface and the second surface.
5 . The method according to claim 1 , wherein applying ultrasonic waves in step (ii) comprises generation of cavitation in the liquid.
6 . The method according to claim 1 , wherein applying ultrasonic waves in step (ii) comprises application of sound power of at least 20 W.
7 . The method according to claim 1 , wherein applying ultrasonic waves in step (ii) comprises application of sound power of up to 10,000 W.
8 . The method according to claim 1 , wherein applying ultrasonic waves in step (ii) is carried out over a period of time of at least 30 s.
9 . The method according to claim 1 , wherein the ultrasonic waves are applied in a dose in the range from 0.2 to 8 W/cm 2 .
10 . The method according to claim 1 , wherein the method comprises modification of the membrane surface.
11 . The method according to claim 10 , wherein the ultrasonic waves are applied in a dose in the range of from 0.4 to 6 W/cm 2 .
12 . A polymeric membrane, obtained by the method according to claim 1 .
13 . The membrane according to claim 12 , wherein a filtration capacity was increased by at least 5%.
14 . The method according to claim 1 , wherein said ultrasonic waves increased the filtration capacity of said microporous membrane by at least 5%, preferably by at least 10%, more preferably by at least 15%.