Project
Silica templating approach for in-column radical polymerisation of low domain size polymer monoliths.
This project intends to use HPLC columns packed with porous silica material as templates for incolumn
polymerization. Preliminary work showed that it is possible to polymerize styrene and
divinylbenzene in the pores of C18 material packed in an HPLC column. When using ODS material
with broader 1000Ä pores inter-connections between the particles appear. The goal of this project is
to work out these observations to be able to make monolithic columns for HPLC with improved
order and therefore higher separation efficiency. In the first inner pore polymerization approach
thermally initiated radical polymerization is performed in the hydrophobic pores of, and at the
connection points between, particles. The particles are in this mode surrounded by water. Reaction
is started by heating the column above the dissociation temperature of the initiator. After the
reaction the particles can selectively be removed in a 20% NaOH solution, leaving only the
monolithic structure behind. In the complimentary through pore polymerization approach the pores
of native silica are filled with water and thermally initiated polymerization is performed in the
through pores only. This strategy is compatible with radical and ionic (resin type) polymerization
approaches offering promise for obtaining mechanically more stable polymer monoliths with
smaller domain sizes. All columns and manufactured materials will be evaluated in a fundamental
and practical way in the two research groups, respectively.