Disclosed is a process for preparing an antimicrobial article wherein a silver colloid is formed in situ as a result of the components employed. The process comprises the steps of (i) providing a liquid which contains a soluble polar polymer in a solvent selected from certain polar organic solvents (ii) adding a silver salt selected from alpha functionalized silver carboxylates to said liquid (iii) allowing the mixture to react with formation of a silver colloid and (iv) separating the solvent from the mixture and forming of the antimicrobial article. The antimicrobial articles thus obtained may be sheets films fibres coating layers and especially membranes like a semipermeable membrane for ultrafiltration water separation or gas separation.
