Method for mineralising a biopolymer membrane and membranes thereby obtained

Abstract

The present invention relates to a method for mineralising a biopolymer membrane, comprising the following steps: a) Introduction of an assembly (3) constituted of a biopolymer membrane (4) comprised between two cellulose sheets (A) and (B), in a vessel comprising: a first compartment (1) and a second compartment (2), each comprising an electrode, a first electrode being an anode placed in the first compartment (1) and a second electrode being a cathode placed in the second compartment (2), the walls of the first compartment (1) and the second compartment (2) brought into contact with one another each having an opening placing in communication the first and the second compartments, the assembly (3) being arranged in said opening between the first and the second compartments in such a way as to close it, the cellulose sheet (A) being on the side of the first compartment (1) and the cellulose sheet (B) on the side of the second compartment (2), b) filling the first compartment (1) with an aqueous solution containing at least one cation chosen from: calcium ions, silver ions, zinc ions, copper ions, sodium ions, magnesium ions and aluminium ions, and the second compartment (2) with an aqueous solution containing at least one anion chosen from fluoride ions, sulphate ions, carbonate ions, silicate ions and phosphate ions; c) application of an electrical voltage between the electrodes; d) turning over the assembly (3) in such a way that the cellulose sheet (A) is on the side of the second compartment and the cellulose sheet (B) on the side of the first compartment, or exchange of the solutions and electrodes of the first and the second compartments; c′) application of an electrical voltage between the electrodes, said voltage being equal to that applied at step (c) and being applied for a duration identical to that of step (c); e) removal and rinsing of the assembly (3); f) recovery and drying of the mineralised biopolymer membrane.

Dependencies are inferred from the claim text.