Semipermeable polymers and method for producing same

A method of making a composite semipermeable membrane, said method comprising the steps of:

• coating a porous support with an anhydrous solution comprising an anhydrous solvent, a polyfunctional secondary amine and a pre-polymer deposition catalyst, so as to form an activated pre-polymer layer on said porous support;
• drying the activated pre-polymer layer, partially or completely, in the absence of water vapor;
• contacting said dried activated pre-polymer layer with an anhydrous, organic solvent solution comprising a polyfunctional amine-reactive reactant so as to interfacially condense said amine-reactive reactant with said polyfunctional secondary amine, thereby forming a cross-linked, interfacial polyamide layer on said porous support to form a composite semipermeable membrane;
• and
• impregnating nanoparticles selected from heavy metals, oxides of heavy metals and combinations thereof onto the cross-linked, interfacial polyamide layer on said composite semipermeable membrane, wherein impregnating the composite semipermeable membrane with nanoparticles comprises:
• diffusing a nanoparticle precursor in liquid solution or vapor state into said composite semipermeable membrane;
• rinsing excess nanoparticle precursor from the composite semipermeable membrane with a solvent;
• and
• thermally converting the nanoparticle precursor to solid nanoparticles in the presence of an inert, reducing, or oxidizing atmosphere.