METHOD FOR GAS PHASE SULFONATION OF POLYMER MEMBRANES

摘要

Methods and apparatus for gas phase sulfonation of preformed polymeric membranes are provided in accordance with the present invention. The invention enables conversion of a hydrophobic membrane that is capable of reaction with a gas phase sulfonation agent into a hydrophilic membrane. As will be understood, aromatic rings, amines, hydroxyl groups, and other reactive moieties in polymers are readily sulfonated when exposed to sulfur trioxide gas. Thus, in accordance with the present invention, a preformed polymer membrane that contains aromatic rings or other moieties that are capable of reaction with a gas phase sulfonation agent, is exposed to a gas phase sulfonation agent, such as sulfur trioxide, and the aromatic rings or other moieties of the polymer become sulfonated. The inclusion of sulfonate groups on such polymers, and the membranes formed therefrom, renders such polymers totally or partially hyrophilic. The invention also relates to polymeric membranes, including asymmetric sulfone polymer membranes sulfonated by the process of the invention, and to devices for carrying out the sulfonation method of the invention.