Abstract: A bipolar membrane BP characterized in that particles 5 of a basic metal chloride are distributed in the interface between a cation-exchange membrane 1 and an anion-exchange membrane 3.

Abstract: To provide a bipolar membrane featuring improved adhesion between an anion-exchange membrane and a cation-exchange membrane without accompanied by an increase in the membrane voltage. [Means for Solution] A bipolar membrane comprising a cation-exchange membrane and an anion-exchange membrane joined together facing each other, wherein at least one of the ion exchange membranes contains a chlorinated polyolefin.

Abstract: To provide a bipolar membrane featuring improved adhesion between an anion-exchange membrane and a cation-exchange membrane without accompanied by an increase in the membrane voltage. [Means for Solution] A bipolar membrane comprising a cation-exchange membrane and an anion-exchange membrane joined together facing each other, wherein at least one of the ion exchange membranes contains a chlorinated polyolefin.

Abstract: A method and an apparatus for producing an apoprotein with which the apoprotein can be efficiently produced from a protein associated with cofactors such as metal ions. The method includes the step of adding an acid to a solution which contains a holoprotein, which is associated with a cofactor which is to be released under acidic conditions, and concentrating the solution with an ultrafiltration membrane. Accordingly, an apoprotein, which has released its cofactor, is produced, and the released cofactor is removed through the membrane along with the acid without reassociating with the apoprotein.

Abstract: An ion-exchange membrane having excellent resistance against organic fouling by high molecular weight organic ions etc. and showing low electric resistance is provided. Said ion-exchange membrane is characterized by that a polyether compound containing polyalkylene glycol chain, such as polyethylene glycol, polypropylene glycol, their derivatives, etc., is fixed on the surface and/or inside of the membrane. As examples of the mode of the fixation there are mentioned fixation by entanglement of the molecules forming the membrane and the molecules of the polyether compound, physical fixation of both molecules by the anchor effect, and chemical fixation of both molecules by the formation of covalent bond or ionic bond. Said ion-exchange membrane can be preferably used in case of removing low molecular weight electrolytes from an aqueous solution containing low molecular weight electrolytes and high molecular weight organic ions etc. through electrodialysis.

Abstract: An ion-exchange membrane having excellent resistance against organic fouling by high molecular weight organic ions etc. and showing low electric resistance is provided. Said ion-exchange membrane is characterized by that a polyether compound containing polyalkylene glycol chain, such as polyethylene glycol, polypropylene glycol, their derivatives, etc., is fixed on the surface and/or inside of the membrane. As examples of the mode of the fixation there are mentioned fixation by entanglement of the molecules forming the membrane and the molecules of the polyether compound, physical fixation of both molecules by the anchor effect, and chemical fixation of both molecules by the formation of covalent bond or ionic bond. Said ion-exchange membrane can be preferably used in case of removing low molecular weight electrolytes from an aqueous solution containing low molecular weight electrolytes and high molecular weight organic ions etc. through electrodialysis.