A substrate comprising a crosslinked polymer primer layer, and grafted thereto a ligand-functionalized polymer is provided. The grafted polymer has the requisite affinity for binding neutral or negatively charged biomaterials, such as cells, cell debris, bacteria, spores, viruses, nucleic acids, and proteins, at pH's near or below the pI's of the biomaterials.

The present invention relates to a forward osmosis-based separation membrane based on a multilayer thin film, using crosslinking between organic monomers, and a preparation method therefore, and in the preparation of the forward osmosis-based separation membrane including a support layer and a selective layer, a middle layer is provided between the support layer and the selective layer so as to prevent a phenomenon in which the selective layer is filled in a pore of the support layer, such that the thickness of a multilayer thin film constituting the selective layer is optimized, and excellent water permeability, salt removal rate and pollution resistance properties are exhibited through the support layer having a structure of uniform surface pores and minimized pore distortion.

The present invention provides a cation-exchange composite membrane comprising a copolymer containing a styrene repeating unit introduced with a sulfonation group, a tert-butylstyrene repeating unit and a crosslink repeating unit, an olefin additive, a plasticizer and a polyvinyl halide polymer.

The cation-exchange composite membrane comprising a copolymer containing a styrene repeating unit introduced with a sulfonation group, a tert-butylstyrene repeating unit and a crosslink repeating unit, an olefin additive, a plasticizer and a polyvinyl halide polymer of the present invention not only displays low electrical resistance, excellent ion exchange capability, excellent ionic conductivity, excellent mechanical properties, excellent chemical properties, and processability, but also is easy to regulate its ion exchange ability and ionic conductivity. Also, the composite membrane of the invention is easier to produce and cheaper to manufacture than the conventional cation-exchange composite membrane.

The present invention provides an anion-exchange composite membrane comprising a copolymer containing a vinylbenzyl trialkylammonium salt repeating unit, a styrene repeating unit and a divinylbenzene derived repeating unit; an olefin additive; a plasticizer; and a polyvinyl halide polymer.

The anion-exchange composite membrane comprising a copolymer containing a vinylbenzyl trialkylammonium salt repeating unit, a styrene repeating unit and a divinylbenzene derived repeating unit; an olefin additive; a plasticizer; and polyvinylidene fluoride of the present invention not only displays low electrical resistance, excellent ion exchange capability, excellent ionic conductivity, excellent mechanical properties, excellent chemical properties, and processability, but also is easy to regulate its ion exchange capacity and ionic conductivity. Also, the composite membrane of the invention is easier to produce and cheaper to manufacture than the conventional anion-exchange composite membrane.

Described in the present application are methods of producing silane-crosslinked polymer membranes at moderate temperatures using acid catalysts that, in certain embodiments, result in membranes with unexpectedly high permeabilities and selectivities. In certain embodiments, grafting and crosslinking of the silanes occur by immersing a preformed membrane in a solution comprising a silane and an acid catalyst. Alternatively, in certain embodiments, grafting of silanes to a polymer occurs in the presence of acid catalyst in solution and subsequent casting and drying produces crosslinked membranes. In certain embodiments, an acid catalyst is a weak acid catalyst. Also described in the present application are asymmetric crosslinked polymer membranes with porous layers. In certain embodiments, crosslinked cellulose acetate membranes have permeability up to an order of magnitude greater than the permeability of unmodified cellulose acetate membranes. The membranes have porous layers with a high porosity due to their processing in moderate conditions.

In one aspect, catalytic membranes are described herein. In some embodiments, a catalytic membrane comprises a surface functionalized with a polymer, the polymer comprising cellulose solubilization functionalities and acid functionalities for the catalytic hydrolysis of cellulose and/or hemicellulose.

To provide: a purification method which uses a polyimide and/or polyamide imide porous membrane that exhibits excellent removal performance for impurities such as metals, and wherein a liquid that is a silylating agent liquid, a film forming material or a diffusing agent composition is an object to be purified; a purification method for purifying a silicon compound-containing liquid that contains a silicon compound which is capable of producing a silanol group by hydrolysis; a method for producing a silylating agent liquid, a film forming material or a diffusing agent composition, which uses the purification method; a filter medium which is composed of the above-described porous membrane; and a filter device which comprises the above-described porous membrane. A purification method for purifying a liquid, which comprises a step in which some or all of the liquid is caused to permeate through a polyimide and/or polyamide imide porous membrane having communicating pores from one side to the other side by means of differential pressure, and wherein the liquid is a silylating agent liquid, a film forming material or a diffusing agent composition that is used for diffusing a dopant into a semiconductor substrate.

A desalination apparatus and a method of desalinating thereof, wherein the desalination apparatus comprises a perforated vessel and at least one engineered semi-permeable membrane that covers perforations on the perforated vessel, wherein the desalination apparatus forms a purified water from saline water when submerged in the saline water to a depth of 50-250 m to create sufficient pressure differential on both sides of the engineered semi-permeable membrane, wherein low-saline water flows through the engineered semi-permeable membrane and collected within an internal cavity of the desalination apparatus. Various embodiments of the desalination apparatus and the method of desalinating are also provided.

Grafted, asymmetric, porous, ultra high molecular weight polyethylene membranes having a bubble point between about 5.38 bar (78 psi) and 11.03 bar (160 psi) are disclosed. Monomers are grafted to the porous polymeric membrane surfaces, the monomers having one or more of neutral groups or ion exchange groups grafted to one or more surfaces of the membrane. A combination of two photoinitiators can be used to graft the monomers to the asymmetric, porous, ultra high molecular weight membrane resulting in grafted microporous membranes that have water flow rates that are at least 50% of the water flow rate of an ungrafted, asymmetric, porous ultra high molecular weight polyethylene membrane. The grafted membrane also wets in water.

A membrane includes a porous base membrane and a hydrophilic coating. The coating comprises a hydrophilic additive and a hydrophilic polymer derivatized with an electron beam reactive group adapted to form a radical under high energy irradiation. In some embodiments, the membrane comprises a fluoropolymer. Also disclosed are processes for forming the membrane.