Porous membrane having hydrophilic surface and process
AssigneeMillipore Corporation
InventorMichael J. Steuck
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Abstract
A composite porous membrane is formed from a porous polymeric membrane having desired bulk properties on which is directly coated a cross-linked polymer having desired surface properties. The composites membrane retains the porosity of the porous polymeric membrane. A preferred composite porous membrane is formed from a porous polyvinylidene fluoride to which is directly coated with a polymer formed of a cross-linked hydroxyalkyl acrylate.
Claims38
A composite porous thermoplastic membrane which comprises a porous membrane substrate having an average pore size between about 0.001 and 10 microns formed of a first polymer, said substrate being directly coated on its entire surface with a cross-linked second polymer formed from a monomer polymerized in situ with a free radical initiator and cross-linked in situ on said substrate, said composite porous membrane having essentially the same porous configuration as said porous membrane substrate.
The process for forming a composite porous membrane formed from a porous membrane substrate having an average pore size between about 0.001 and 10 microns formed of a first polymer, said substrate being directly coated over its entire surface with a crosslinked second polymer, said composite porous membrane having essentially the same porous configuration as said porous membrane substrate which comprises:
- (a) washing said porous membrane substrate to wet the surfaces of the pores in said porous membrane;
- and
- (b) contacting said porous membrane from step (a) with a solution of a monomer of said second polymer, a cross-linking agent for said monomer and a polymerization initiator for said monomer under conditions to polymerize said monomer and to cross-link said second polymer in situ over the entire surface of said first polymer under conditions to avoid plugging of said pores.
Dependencies are inferred from the claim text.