Charge mosaic membranes useful for desalination applications, and methods of making and using the same, are described.

The present invention provides a porous hollow fiber membrane suitable for the removal of minute substances, e.g., viruses, contained in a liquid. The present invention relates to a porous hollow fiber membrane which is provided with a separation-functioning layer containing a fluororesin, has a gas diffusion amount of 0.5 to 5.0 mL/m.sup.2/hr as measured in a diffusion test, and also has foaming points at a density of 0.005 to 0.2 point/cm.sup.2 as measured in a foaming test under the immersion in 2-propanol.

The present invention provides a porous hollow fiber membrane suitable for the removal of minute substances, e.g., viruses, contained in a liquid. The present invention relates to a porous hollow fiber membrane which is provided with a separation-functioning layer containing a fluororesin, has a gas diffusion amount of 0.5 to 5.0 mL/m.sup.2/hr as measured in a diffusion test, and also has foaming points at a density of 0.005 to 0.2 point/cm.sup.2 as measured in a foaming test under the immersion in 2-propanol.

Disclosed are a method for preparing a high-strength anti-pollution anti-bacterial hollow fiber nano-filtration membrane and a product prepared by the method. The method comprises: S1, a chemical crosslinking reaction: placing an ultra-filtration base membrane in an acidic aqueous solution of glucose or an aqueous solution of phytic acid for a chemical crosslinking reaction to obtain a nano-filtration membrane; S2, a neutralization reaction immersing the nano-filtration membrane obtained in step S1 in an aqueous solution of alkali for the neutralization reaction, then washing the membrane to be neutral; S3, loading inorganic antibacterial agent: placing the membrane obtained in step S2 in an inorganic anti-bacterial agent solution for complexation, thereby obtaining a high-strength anti-pollution anti-bacterial hollow fiber nano-filtration membrane.

Disclosed are a method for preparing a high-strength anti-pollution anti-bacterial hollow fiber nano-filtration membrane and a product prepared by the method. The method comprises: S1, a chemical crosslinking reaction: placing an ultra-filtration base membrane in an acidic aqueous solution of glucose or an aqueous solution of phytic acid for a chemical crosslinking reaction to obtain a nano-filtration membrane; S2, a neutralization reaction immersing the nano-filtration membrane obtained in step S1 in an aqueous solution of alkali for the neutralization reaction, then washing the membrane to be neutral; S3, loading inorganic antibacterial agent: placing the membrane obtained in step S2 in an inorganic anti-bacterial agent solution for complexation, thereby obtaining a high-strength anti-pollution anti-bacterial hollow fiber nano-filtration membrane.

The disclosure relates to processes, related polyacid polymers, and related articles for functionalizing a porous membrane by contacting the membrane with a polyacid polymer at low pH to stably adsorb a polyacid layer on the membrane pore surface, in particular polyacid polymers including repeating units with a pendent metal-binding ligand or star polyacid polymers. The resulting functionalized membrane is characterized by a high density of free acid groups, resulting in a higher specific capacity for its intended application. The process allows functionalization of porous membranes in a very simple, one-step process, for example without a need to derivatize an adsorbed polyacid layer to impart metal-binding ligand functionality thereto. Such functional membranes may find multiple uses, including rapid, selective binding of proteins for their purification or immobilization.

The disclosure relates to processes, related polyacid polymers, and related articles for functionalizing a porous membrane by contacting the membrane with a polyacid polymer at low pH to stably adsorb a polyacid layer on the membrane pore surface, in particular polyacid polymers including repeating units with a pendent metal-binding ligand or star polyacid polymers. The resulting functionalized membrane is characterized by a high density of free acid groups, resulting in a higher specific capacity for its intended application. The process allows functionalization of porous membranes in a very simple, one-step process, for example without a need to derivatize an adsorbed polyacid layer to impart metal-binding ligand functionality thereto. Such functional membranes may find multiple uses, including rapid, selective binding of proteins for their purification or immobilization.

A composite membrane for selectively pervaporating a first liquid from a mixture comprising the first liquid and a second liquid. The composite membrane includes a porous substrate comprising opposite first and second major surfaces, and a plurality of pores. A pore-filling polymer is disposed in at least some of the pores so as to form a layer having a thickness within the porous substrate. The polymer is more permeable to the first liquid than the second liquid but not soluble in the first liquid or the second liquid. The composite membrane may be asymmetric or symmetric with respect to the amount of pore-filling polymer throughout the thickness of the porous substrate.

A composite membrane for selectively pervaporating a first liquid from a mixture comprising the first liquid and a second liquid. The composite membrane includes a porous substrate comprising opposite first and second major surfaces, and a plurality of pores. A pore-filling polymer is disposed in at least some of the pores so as to form a layer having a thickness within the porous substrate. The polymer is more permeable to the first liquid than the second liquid but not soluble in the first liquid or the second liquid. The composite membrane may be asymmetric or symmetric with respect to the amount of pore-filling polymer throughout the thickness of the porous substrate.

The present invention provides a gel containing a crosslinked polymer having at least one selected from the group consisting of an acidic dissociative group, an acidic dissociative group in a salt form, and a derivative group of an acidic dissociative group, and a condensate of a compound represented by the following formula (I): Si{R.sup.1N(R.sup.2)(R.sup.3)}(OR.sup.4)(OR.sup.5)(R.sup.6) (wherein each group is as defined in the DESCRIPTION).