Abstract: A method for producing a porous copolymer monolith substrate for use in flow through liquid chromatography applications is disclosed. The method comprises forming a reaction composition comprising at least one monoethylenically unsaturated aryl monomer, at least one polyethylenically unsaturated aryl monomer, a RAFT agent, at least one liquid porogen, and a radical initiator. The reaction composition is introduced to a mold having a shape and dimensions suitable for forming a liquid chromatography substrate. The monoethylenically unsaturated aryl monomer, the polyethylenically unsaturated aryl monomer and the RAFT agent are copolymerised in the mold under conditions to form a solid copolymer network that is phase-separated from the reaction composition and/or any liquid components.