Abstract: Polymeric microfibrous structures comprised of normally hydrophobic microfibers coated with a cured, precipitated, cationic, thermosetting binder resin or polymer and characterized by being hydrophilic and having a positive zeta potential with enhanced capability for the removal of negatively-charged particulate material in a fluid medium are prepared by a process comprising the steps:(1) combining in a controlled manner a first solution of a water-soluble, non-colloidal, cationic, thermosetting binder resin or polymer and a second solution or dispersion of a precipitating agent to form a stable emulsion or suspension;(2) impregnating the microfibrous structure of normally hydrophobic microfibers with the stable emulsion or suspension to form a fibrous structure wetted with the stable emulsion or suspension; and(3) drying the wetted microfibrous structure and curing the binder resin or polymer.