Abstract: Dopable, fully dense polymer membranes are used to form membranes having selective permeabilities. To improve selectivity, the membranes may be subjected to chemical or electrochemical treatment with electron donors or acceptors to alter the doping level of the polymer membrane, generally in a reversible fashion. This leads to significant changes in gas permeation rates relative to what is observed for the non-doped, fully dense polymers. This change in doping level of the polymer films can be precisely controlled by varying the concentration and nature of chemical dopants used. Desirable changes in permeation rates are achieved by a treatment which comprises a reversal doping of the polymeric material, followed by removal of the dopants (to provide an "undoped" polymer).

Abstract: Dopable, fully dense polymer membranes are used to form membranes having selective permeabilities. To improve selectivity, the membranes may be subjected to chemical or electrochemical treatment with electron donors or acceptors to alter the doping level of the polymer membrane, generally in a reversible fashion. This leads to significant changes in gas permeation rates relative to what is observed for the non-doped, fully dense polymers. This change in doping level of the polymer films can be precisely controlled by varying the concentration and nature of chemical dopants used. Desirable changes in permeation rates are achieved by a treatment which comprises a reversal doping of the polymeric material, followed by removal of the dopants (to provide an "undoped" polymer).

Abstract: A monolithic bipolar membrane having elastic properties is wetted with a polar solvent or an electrolyte, such as water. An electric field is used to control the transfer rate of gas molecules through the membrane in response to an applied external electromotive force. By adjusting the electromotive force the membrane can be controlled to selectively pass one type of molecule while rejecting other molecules. A separation between molecules of two or more materials can thus be achieved.

Abstract: A monolithic bipolar membrane having elastic properties is immersed in a polar solvent or an electrolyte, such as water. An electric field is used to control the transfer rate of neutral or ionized molecules in solution in the electrolyte through the membrane in response to an applied external electromotive force. By adjusting the external electromotive force the membrane can be controlled to selectively pass one type of molecule while rejecting other molecules in solution. A separation between molecules of two or more materials in solution in the electrolyte can thus be achieved.