- Group Sijbesma -

The Supramolecular Polymer Chemistry group has recently started and is developing a research programme that is aimed at making sophisticated use of specific supramolecular interactions in the design of polymeric materials with functionality on the nanometer length scale. In particular multiple hydrogen bonding interactions and reversible metal coordination are employed in thermoplastic elastomers and in liquid crystalline materials.

Supramolecular Polymers

In our first line of research that is performed jointly with the Macro-Organic Chemistry group (section A), complementary and self-complementary multiple hydrogen bonding units are used to form supramolecular polymers. With the introduction of novel, complementary hydrogen bonding units, it has become possible to develop supramolecular block copolymers and also more complex architectures such as hyperbranched and grafted supramolecular polymers are now within reach. Part of the work within this theme is focused on the design and optimization of multiple hydrogen bonding units, as well as on the study of their fundamental association properties.

Nanoporous Membranes

The development of nanoporous membranes is the main goal of the second line of research. These materials have an enormous potential for biomedical applications, such as nanofiltration membranes for dialysis and miniaturized diagnostic devices. Thin films with a high density of monodisperse pores of 1-10 nm in size are being developed from photopolymerizable liquid crystalline materials with discotic phases. A combination of microphase separation between incompatible moieties, and highly specific noncovalent interactions is essential to achieve the desired goal.

Catalytic Printing

Novel ways to transfer the nanometer-scale order of block copolymers onto other surfaces by soft lithographic techniques are important aspects in the implementation of nanotechnology and are studied in a third research line. The use of soft lithographic techniques such as microcontact printing is investigated, making use of tailored polymers which are functionalized in a supramolecular fashion with e.g . functionalities for catalytic printing.

Mechanochemistry

The study of mechanically induced chemistry is an exciting new direction in the research of this group. This last line of research targets the modification of molecular properties (catalytic activity, spin state, optical properties) of transition metal complexes through macroscopic mechanical forces.

Presently, the focus is on transition metal catalysts which are embedded in the matrix of an elastic material, and whose activity and profile can be tuned by mechanical forces.