Abstract: Water insoluble polymers are treated to place on their exposed surfaces the pendant alkyl imidocarbonyl (amide) groups to impart a high degree of hydrophilicity to that surface. Nitrile-containing polymers or copolymers in the form of insoluble films, filters or membranes are treated to convert a substantial fraction of the surface nitrile groups into the corresponding amide by the use of hydrogen peroxide or concentrated acids. The surface is rendered hydrophilic and resistant to fouling to the extent that even proteins are not denatured thereupon. The surface may also be converted to substituted amides by subsequent reactions to impart to it other functionalities or to serve as the basis for coupling reactions. Other polymers capable of surface treatment to produce pendant amidocarbonyl groups include ones containing pendant esters which on cleavage of the oxygen-carbon bond give pendant alcohol groups.

Abstract: Cross-linked polymeric gels or films are prepared by dissolving in a suitable solvent a linear polymer or polymers at least one of which is predominantly (at least 80%) made from monomers containing pendant amidocarbonyl or oxycarbonyl groups. For the cross-linking reaction are present either hydroxyl groups, present as either pendant groups from the polymer, or as low molecular weight polyols; or amino groups, present as either pendant groups from the polymer, or as low molecular weight diamines or polyamines. Either no catalyst is present or a strongly acidic catalyst (which may also be a pendant group on a polymer) is used. The solvent is removed by coagulation and/or drying and the dry material is heat-cured, thus cross-linking and insolubilizing the polymer or polymers.

Abstract: Water insoluble polymers are treated to place on their exposed surfaces the pendant alkyl imidocarbonyl (amide) groups to impart a high degree of hydrophilicity to that surface. Nitrile-containing polymers or copolymers in the form of insoluble films, filters or membranes are treated to convert a substantial fraction of the surface nitrile groups into the corresponding amide by the use of hydrogen peroxide or concentrated acids. The surface is rendered hydrophilic and resistant to fouling to the extent that even proteins are not denatured thereupon. The surface may also be converted to substituted amides by subsequent reactions to impart to it other functionalities or to serve as the basis for coupling reactions. Other polymers capable of surface treatment to produce pendant amidocarbonyl groups include ones containing pendant esters which on cleavage of the oxygen-carbon bond give pendant alcohol groups.

Abstract: A process for the treatment of an aqueous stream containing an acid or base and typically a precipitatable material such as a metal ion comprises:(a) subjecting the aqueous stream to (i) a treatment to produce a relatively pure stream of water and a concentrated aqueous stream, and (ii) water splitting to produce a stream of base, a stream of acid and a dilute aqueous stream of a concentration lower than the concentrated aqueous stream, the treatments (i) and (ii) being effected in either order,(b) recycling at least part of the pure water stream produced in (a) (i) to an earlier stream either in the production leading to said aqueous stream or to step (i) or (ii),(c) recycling at least part of the acid and/or base streams produced in (a) (ii) to an earlier stream either in the production leading to said aqueous stream or to an earlier step in the process, and(d) recycling at least part of the lower concentration stream produced in (a) (ii) to either (a) (i) or to another step in the process, whereby, when pr

Abstract: A membrane is produced by dissolving, in a water-miscible solvent, a water insoluble copolymer of acrylontrile with at least one monomer selected from the group consisting of an aminostyrene, a vinyl pyridine and an N-hydroxy-containing-substituent-acrylamide, casting said solution to form a thin layer of solution, contacting said solution with water thereby to coagulate the copolymer into a film, and washing away from the copolymer film the solution of solvent and water. The amine or hydroxy group of the copolymer is then activated and coupled with a ligand such as glucose isomerase, chymotrypsin or Protein A. The coupled membranes can then be used for biological separations and reactions.

Abstract: A process for the treatment of an aqueous stream containing an acid or base and typically a precipitatable material such as a metal ion comprises:(a) subjecting the aqueous stream to (i) a treatment to produce a relatively pure stream of water and a concentrated aqueous stream, and (ii) water splitting to produce a stream of base, a stream of acid and a dilute aqueous stream of a concentration lower than the concentrated aqueous stream, the treatments (i) and (ii) being effected in either order,(b) recycling at least part of the pure water stream produced in (a)(i) to an earlier stream either in the production leading to said aqueous stream or to step (i) or (ii),(c) recycling at least part of the acid and/or base streams produced in (a)(ii) to an earlier stream either in the production leading to said aqueous stream or to an earlier step in the process, and(d) recycling at least part of the lower concentration stream produced in (a)(ii) to either (a)(i) or to another step in the process, whereby, when presen

Abstract: Cross-linked polymeric gels or films are prepared by dissolving in a suitable solvent a linear polymer or polymers containing pendant amidocarbonyl or oxycarbonyl groups, hydroxyl groups present as either pendant groups from the polymer or as a low molecular weight polyol, and a strongly acidic catalyst (which may also be a pendant group on a polymer). The solvent is removed by coagulation and/or drying and the dry material is heat-cured, thus cross-linking and insolubilizing the polymer or polymers.

Abstract: An aliphatic organic acid fraction is separated from the kraft black liquor by subjecting the liquor to ultrafiltration, treating the resulting permeate by electrodialysis, acidifying the resultant deionate to about pH 4-5, separating the lignin solids which precipitate following this acidification, raising the pH of the separated solution to about 7-8 and finally subjecting the neutralized solution to electrodialytic water-splitting.

Abstract: Pressure-driven affinity sorption membranes are prepared from a membrane filter composed of an insoluble matrix polymer or an interpolymer composite and used for separation and purification by passing therethrough solutions containing mixtures, one or more of which forms a specific complex with the ligand on the pore surface of the membrane, washing out the uncoupled solutes, then employing an appropriate displacing or eluting agent to recover the desired component in a pure and concentrated state, all under pressure-driven conditions.

Abstract: Pressure-driven conditions are used to activate and couple enzymes to ultrafiltration membranes such as a homoporous cellulosic membrane having pores of about 15-200 angstroms in diameter. The resultant enzyme-coupled ultrafiltration membranes can be used under pressure-driven conditions for enzymatic conversion of a substrate. The rate of conversion at low substrate concentrations is larger than the rate achieved with the native enzyme.

Abstract: Pressure-driven enzyme-coupled membranes are prepared starting with a membrane filter having pores of appropriate, molecular dimensions and composed of a polymeric matrix, the activation of that matrix (where necessary) under pressure-driven conditions to impart to it appropriate groups capable of coupling to enzymes and similar substances of biological activity under pressure-driven conditions, and then employing this system under pressure-driven conditions to effect conversion processes which include the use of the coupled enzymes as the catalysts.

Abstract: Interpolymer fixed-charge membranes of macroscopic homogeneity are prepared by providing a solution containing a matrix polymer, a polyelectrolyte and a crosslinking agent, evaporating the solvent until substantially the desired pore size and other physical properties are obtained in a film cast from the solution, the thereafter chemically crosslinking the film to insolubilize the membrane.