Cationically charge-modified membranes

A charge-modified integral polymer membrane, said membrane comprising a hydrophobic polymer, said membrane being initially hydrophobic, said initially hydrophobic membrane being rendered hydrophilic by charge-modification, said charge modification resulting from contacting said membrane with at least one polymeric wetting agent, said charge-modification further resulting from crosslinking to said membrane at least one polymeric cationic charge-modifying agent, wherein said cationic charge modifying agent comprises a first agent or a second agent, or both said first and second agent in combination, wherein said first agent comprises a polyamine or an aziridine-ethylene oxide copolymer, wherein said first agent is free of any epoxide or epichlorohydrin chemical crosslinking substituents, and wherein said second agent comprises an epichlorohydrin-modified polyamine.

A charge-modified integral polymer membrane, said membrane comprising a hydrophobic polymer, said membrane being initially hydrophobic, said initially hydrophobic membrane being rendered hydrophilic by charge-modification, said charge modification resulting from contacting said membrane with at least one polymeric wetting agent, said charge-modification further resulting from crosslinking to said membrane at least one polymeric cationic charge modifying agent, wherein said cationic charge modifying agent comprises a first agent or a second agent, or both said first and second agent in combination, wherein said first agent comprises a polyamine or an aziridine-ethylene oxide copolymer, and wherein said second agent comprises an epichlorohydrin-modified highly branched polyamine.

A charge-modified integral polymer membrane, said membrane comprising a hydrophobic polymer, said membrane being initially hydrophobic, said initially hydrophobic membrane being rendered hydrophilic by charge-modification, said charge modification resulting from contacting said membrane with at least one polymeric wetting agent, said charge-modification resulting from crosslinking to said membrane at least one polymeric cationic charge-modifying agent, wherein said, cationic charge modifying agent comprises a first agent and a second agent wherein said first agent comprises a polyamine or an aziridine-ethylene oxide copolymer, wherein said second agent comprises an epichlorohydrin-modified polyamine, and wherein said membrane is contacted with said first agent and said second agent simultaneously.

A charge-modified integral polymer membrane, said membrane comprising a hydrophobic polymer, said membrane being initially hydrophobic, said initially hydrophobic membrane being rendered hydrophilic by charge-modification, said charge modification resulting from contacting said membrane with at least one polymeric wetting agent, said charge modification further resulting from crosslinking to said membrane at least one polymeric cationic charge-modifying agent, wherein said membrane comprises a melt-blown polymer membrane.

A charge-modified integral polymer membrane, said membrane comprising a hydrophobic polymer, said membrane being initially hydrophobic, said initially hydrophobic membrane being rendered hydrophilic by charge-modification, said charge modification resulting from contacting said membrane with at least one polymeric wetting agent, said charge modification further resulting from crosslinking to said membrane at least one polymeric cationic charge-modifying agent, wherein said membrane comprises a hollow fiber membrane.

A charge-modified integral polymer membrane, said membrane comprising a hydrophobic polymer, said membrane being initially hydrophobic, said initially hydrophobic membrane being rendered hydrophilic by charge-modification, said charge modification resulting from contacting said membrane with at least one polymeric wetting agent, said charge modification further resulting from crosslinking to said membrane at least one polymeric cationic charge-modifying agent, wherein said membrane comprises a filter cartridge.

A positively charged polymer membrane, said membrane being cast from a formulation comprising a sulfone polymer and a copolymer comprising vinylpyrrolidone and a cationic imidazolinium compound, said formulation further comprising a low molecular weight organic acid and a solvent.

A method of preparing a positively charged polymer membrane, comprising the steps of:

• casting in a film a mixed polymer formulation comprising a sulfone polymer, a copolymer of vinylpyrrolidone and a cationic imidazolinium compound, said formulation further comprising a low molecular weight organic acid and a solvent;
• and
• quenching said film in an aqueous bath to produce a coagulated membrane.