Silica ultrafiltration membrane with tunable pore size for macromolecule separation

•The mesoporous silica membranes have abundant, accessible, wormlike pores.•The membranes have narrow pore-size distributions and tunable pore sizes.•The membranes are prepared using phosphoric acid as pore-forming agent.•The silica membrane has a potential use in size-exclusive separation of molecules.

An innovative and facile approach for preparing mesoporous silica membranes is described. The prepared membranes possess abundant, accessible, wormlike pores across the membrane. Narrow pore-size distribution and tunable pore sizes ranging from 2 to 6 nm have been obtained by using a sol–gel method with phosphoric acid as pore-forming agent. The prepared membranes have a potential application in ultrafiltration.