Research note: Smart material composite membranes based on molecularly imprinted nanoparticles used for selective filtration

The new separation approach described is an efficient and easy alternative to the established methods for separation of small quantities of specific substances, like preparative HPLC or common SPE kits. The composite membrane used consists of a polymer membrane disc which acts as a support and a selective coating of deposited, molecularly imprinted, nanospheres. In the outer shell of these spherical nanoparticles molecular imprints are accessible which bind the target molecule from the mixture to be treated according to the principle of molecular recognition; the mixture runs through the composite membrane. In this paper we investigate the feasibility of the approach by kinetic experiments, calculating adsorption isotherms and by process modelling. The principal hydrodynamic properties of the composite membrane set-up are evaluated by modelling and flow experiments. Concerning thermodynamic and kinetic parameters, models for affinity characteristics are set up for the e ntire mass transfer through the composite membrane. Our nanoparticle approach already allows a very thin layer to realise separation performance and binding capacities in an interesting working regime. The technology of molecularly imprinted nanospheres offers the potential to cover a broader range of template molecules such that customised separation solutions can be envisaged.