Macroporous polymers made from medium internal phase emulsion templates: Effect of emulsion formulation on the pore structure of polyMIPEs

Emulsion templating is an effective route to prepare low-density, interconnected macroporous polymers known as poly(merised)High and Medium Internal Phase (Ratio) Emulsions. Here, we provide evidence that the interconnectivity of polyMIPEs is strongly dependent on the initiator used for the polymerisation of the continuous phase of the template. The characteristic interconnected pore structure can be observed if an oil soluble initiator, we used α,α′-azoisobutyronitrile, is used irrespectively of the surfactant employed to stabilise the emulsion templates. However, polymerisation of the continuous emulsion phase initiated by water-soluble initiators such as redox initiators or potassium peroxodisulfate results in low pore interconnectivity or even closed celled polyMIPEs.