The present invention relates to improved methods for the preparation of thin film composite membranes by interfacial polymerization, preferably (organic) solvent resistant thin film composite membranes. More in particular the method of the present invention allows for the preparation of thin film composite membranes wherein a thin film is deposited on a porous crosslinked support. Said method comprises the one step solidification, impregnation and crosslinking of the porous support through phase inversion by immersion of the cast membrane polymer film in an (aqueous) solvent comprising a polyfunctional monomers.

A composite gas membrane comprising: a) a porous support; b) an activated gutter layer; c) a discriminating layer located on the gutter layer; and d) optionally a protective layer on the discriminating layer; wherein the said layers remain in place when a peeling force of 2.5 N/1.5 cm is applied to the outermost of said layers.

A composite gas membrane comprising: a) a porous support; b) an activated gutter layer; c) a discriminating layer located on the gutter layer; and d) optionally a protective layer on the discriminating layer; wherein the said layers remain in place when a peeling force of 2.5 N/1.5 cm is applied to the outermost of said layers.

A gas separation composite membrane, containing: a gas-permeable supporting layer; and a gas separating layer containing a crosslinked polyimide resin, over the gas-permeable supporting layer, in which the crosslinked polyimide resin is composed of a polyimide compound having been crosslinked through an ester linking group, in which the polyimide compound contains a repeating unit of formula (I), a repeating unit of formula (II-a) or (II-b), and a repeating unit of formula (III-a) or (III-b), and in which a ratio [κ] of a site forming a crosslinked chain mediated by the ester linking group to an imide group (the number of specific crosslinkable sites/the number of imide groups) is more than 0.4 and less than 0.5.

A gas separation composite membrane, containing: a gas-permeable supporting layer; and a gas separating layer containing a crosslinked polyimide resin, over the gas-permeable supporting layer, in which the crosslinked polyimide resin is composed of a polyimide compound having been crosslinked through an ester linking group, in which the polyimide compound contains a repeating unit of formula (I), a repeating unit of formula (II-a) or (II-b), and a repeating unit of formula (III-a) or (III-b), and in which a ratio [κ] of a site forming a crosslinked chain mediated by the ester linking group to an imide group (the number of specific crosslinkable sites/the number of imide groups) is more than 0.4 and less than 0.5.

Provided is a method for producing a porous polyimide film with which it is possible to suppress the occurrence of curling in the polyimide-fine particle composite film obtained by firing the unfired composite film. The method for producing a porous polyimide film of the present invention includes, in the following order: forming an unfired composite film using a varnish that contains a resin including polyamide acid and/or polyimide, fine particles, and a solvent; immersing the unfired composite film in a solvent including water; firing the unfired composite film to obtain a polyimide-fine particle composite film; and removing the fine particles from the polyimide-fine particle composite film.

Provided is a method for producing a porous polyimide film with which it is possible to suppress the occurrence of curling in the polyimide-fine particle composite film obtained by firing the unfired composite film. The method for producing a porous polyimide film of the present invention includes, in the following order: forming an unfired composite film using a varnish that contains a resin including polyamide acid and/or polyimide, fine particles, and a solvent; immersing the unfired composite film in a solvent including water; firing the unfired composite film to obtain a polyimide-fine particle composite film; and removing the fine particles from the polyimide-fine particle composite film.

Disclosed is a method of modifying a metal-organic framework (MOF), the modified MOF, and methods for using the same. The method of modification can include heating a mixture comprising an azide compound and a MOF to generate a nitrene compound and nitrogen (N2) from the azide compound and covalently bonding the nitrene compound to the MOF to obtain the modified MOF.

Disclosed is a method of modifying a metal-organic framework (MOF), the modified MOF, and methods for using the same. The method of modification can include heating a mixture comprising an azide compound and a MOF to generate a nitrene compound and nitrogen (N2) from the azide compound and covalently bonding the nitrene compound to the MOF to obtain the modified MOF.

The present invention provides a separation membrane suitable for separating water from a liquid mixture containing an alcohol and water. A separation membrane 10 according to the present invention contains polyimide including a structural unit represented by formula (1). A is a linking group having a solubility parameter, in accordance with a Fedors method, of more than 5.0. B is a linking group having a solubility parameter of more than 8.56. R.sup.1 to R.sup.6 each are independently a hydrogen atom, a halogen atom, a hydroxyl group, a sulfonic group, an alkoxy group having 1 to 30 carbon atoms, or a hydrocarbon group having 1 to 30 carbon atoms. Ar.sup.1 and Ar.sup.2 each are a divalent aromatic group.