Method for synthesis of thin film composite membranes

A method for preparing a thin film composite (TFC) membrane comprising a support, which comprises a cross-linked first polymer, and a top layer comprising a film of a second polymer, wherein said method comprises:

• (i) casting a solution of said first polymer onto a suitable substrate;
• (ii) preparing a solidified and impregnated support by immersing said cast first polymer solution into an aqueous coagulation medium comprises first polyfunctional monomers, such that during coagulation of said first polymer, part of said first polyfunctional monomers cross-links said first polymer, while another part of said first polyfunctional monomers are comprised in an aqueous solution that impregnates the solidified first polymer;
• and
• (iii) contacting the solidified and impregnated support of (ii) with a water-immiscible solvent comprising second polyfunctional monomers, whereby said second polyfunctional monomers interfacially polyermise with at least one of the impregnated polyfunctional monomers of (ii) to form a thin film second polymer layer.