Abstract: Cationic charged semihydrophobic polyethersulfone (CSfIP) membranes having hydrophilic and semihydrophobic properties are provided, as well as preparation of the same by post-treatment. Typically, as an illustration, a microporous hydrophilic polyethersulfone membrane substrate which contains non-leachable polymeric additive having functional groups is treated in an alkaline solution for simultaneous or sequential reaction with 1) a primary charge modifying agent which is an epichlorohydrin modified polyamine, and 2) a secondary polymeric charge modifying agent containing a positive charge (or for reaction with the primary charge modifying agent alone); then baked until cured at elevated temperature; and finally washed and dried. The CSHP membranes are used in various applications such as the filtration of fluids and the macromolecular transfer of biomolecules either from electrophoresis gels or directly to immobilization on the membrane for hybridization and stripping.

Abstract: Porous blended hydrophilic copolymer (polyethersulfone resin, poly-2-oxazoline resin, and polyvinylpyrrolidone resin) microporous membranes are provided which are useful for filtering macromolecules or particles from fluids. The invention also concerns a process for filtering matter from a fluid, employing the membranes.

Abstract: Cationic charge modified microporous hydrophilic membranes are provided, as well as preparation of the same by post-treatment. Typically, as an illustration, a microporous hydrophilic membrane substrate which contains non-leachable polymeric additive having functional groups is treated in an alkaline solution for simultaneous or sequential reaction with 1) a primary charge modifying agent which is an epichlorohydrin modified polyamine, and 2) a secondary polymeric charge modifying agent containing a fixed formal positive charge (or for reaction with the primary charge modifying agent alone); then cured at elevated temperature; and finally washed and dried. The cationically charged microporous membranes are used in various applications such as the filtration of fluids and the macromolecular transfer from electrophoresis gels.

Abstract: Microporous membranes can be prepared which comprise a polymer which is a hydrophobic polymer in bulk form and which has an equilibrium water absorption from about 2% to about 4%, but is hydrophilic when precipitated as a membrane. The membranes are further characterized by high water flow rates at any given bubble point.

Abstract: Porous blended polymer (polyethersulfone, phenoxy resin) filtration membranes are provided which are useful for filtering macromolecules or particles from fluids. The invention also concerns a process for filtering matter from a fluid, employing the membranes.

Abstract: Microporous membranes can be prepared which comprise a polymer which is a hydrophobic polymer in bulk form and which has an equilibrium water absorption from about 2% to about 4%, but is hydrophilic when precipitated as a membrane. The membranes are further characterized by high water flow rates at any given bubble point.

Abstract: Microporous membranes can be prepared which comprise a polymer which is a hydrophobic polymer in bulk form and which has an equilibrium water absorption from about 2% to about 4%, but is hydrophilic when precipitated as a membrane. The membranes are further characterized by high water flow rates at any given bubble point.