A method of making a charged hollow fiber membrane, the method comprising: (a) forming at least one coating composition comprising a solvent, dissolvable silica nanoparticles, a membrane-forming polymer, and a charged polymer, wherein the dissolvable silica nanoparticles have a diameter of 50 nm to 1000 nm and a particle density of less than 1.96 g/cm 3 ; (b) coating the at least one coating composition onto a filament; (c) carrying out phase inversion of the at least one coating composition, or the coating compositions, coated onto the filament; (d) dissolving the dissolvable silica nanoparticles and removing the filament from the coated filament to obtain a charged hollow fiber membrane; and optionally (e) washing the charged hollow fiber membrane obtained in (d): wherein the charged polymer is a negatively charged polymer selected from the group consisting of maleic acid-methyl vinyl ether copolymer, polystyrene sulfonic acid, sulfonated polysulfone, sulfonated polyether sulfone, polyacrylic acid, polymethacrylic acid, and polyvinylphenol, or wherein the charged polymer is a positively charged polymer selected from the group consisting of polyethyleneimine, polydiallyldimethylammonium chloride, polyvinylamine, amine terminated polyethylene oxide or polyethylene glycol, poly(2-vinylpyridine), poly(4-vinylpyridine), and poly(1-vinylpyrrolidone-co-2-dimethylaminoethylmethacrylate). (a) forming at least one coating composition comprising a solvent, dissolvable silica nanoparticles, a membrane-forming polymer, and a charged polymer, wherein the dissolvable silica nanoparticles have a diameter of 50 nm to 1000 nm and a particle density of less than 1.96 g/cm 3 ; (b) coating the at least one coating composition onto a filament; (c) carrying out phase inversion of the at least one coating composition, or the coating compositions, coated onto the filament; (d) dissolving the dissolvable silica nanoparticles and removing the filament from the coated filament to obtain a charged hollow fiber membrane; and optionally (e) washing the charged hollow fiber membrane obtained in (d): wherein the charged polymer is a negatively charged polymer selected from the group consisting of maleic acid-methyl vinyl ether copolymer, polystyrene sulfonic acid, sulfonated polysulfone, sulfonated polyether sulfone, polyacrylic acid, polymethacrylic acid, and polyvinylphenol, or wherein the charged polymer is a positively charged polymer selected from the group consisting of polyethyleneimine, polydiallyldimethylammonium chloride, polyvinylamine, amine terminated polyethylene oxide or polyethylene glycol, poly(2-vinylpyridine), poly(4-vinylpyridine), and poly(1-vinylpyrrolidone-co-2-dimethylaminoethylmethacrylate). wherein the charged polymer is a negatively charged polymer selected from the group consisting of maleic acid-methyl vinyl ether copolymer, polystyrene sulfonic acid, sulfonated polysulfone, sulfonated polyether sulfone, polyacrylic acid, polymethacrylic acid, and polyvinylphenol, or wherein the charged polymer is a positively charged polymer selected from the group consisting of polyethyleneimine, polydiallyldimethylammonium chloride, polyvinylamine, amine terminated polyethylene oxide or polyethylene glycol, poly(2-vinylpyridine), poly(4-vinylpyridine), and poly(1-vinylpyrrolidone-co-2-dimethylaminoethylmethacrylate). <EOS>