High capacity organic monoliths for the simultaneous application to biopolymer chromatography and the separation of small molecules

A method for controlling the mesoporous structure of monolithic organic copolymers is presented by systematic variation in polymerisation time, employing poly(p-methylstyrene-co-1,2-(p-vinylphenyl)ethane) (MS/BVPE) as a representative styrene system. Decreasing the time of polymerisation introduces a considerable fraction of mesopores (up to 20% of the total pore volume), while keeping the support permeability reasonable high (∼1.3 × 10−14 m2). Monolith structures, prepared in such a manner, enable efficient (typically around 70,000 plates/m) and fast separation of low-molecular-weight compounds, whereas their performance towards biopolymers is comparable to column supports, fabricated according to typically used protocols (polymerisation time >12 h and thus monomer conversion >98%). The polymerisation time is hence a valuable tool to tailor the fraction of support flow-channels, macropores as well as mesopores, which is shown dramatically to influence the chromatographic separation characteristics of the respective column. This way, the preferred applicability of organic (styrene) monolithic copolymers can be extended to the separation of small molecules beyond biopolymer chromatography.