Jonathan W. Steed报告会

Supramolecular Gels: Responsive Soft Materials

A vast and diverse array of organic compounds and coordination complexes form gels by hierarchical self-assembly either because of hydrophobic effects in water or by more directional interactions such as hydrogen bonding in less polar solvents. Of recent interest is the emergence of metal-, anion and salt-containing gelators based on small-molecule ‘low molecular weight gelators (LMWG).¹ Particular attractions of LMWGs to the scientific community are the reversible nature of the interactions between the gelator molecules, the wide (essentially unlimited) range  of solvents that can be gelled and the possibility of tuning the gels’ behaviour by introducing responsive or switching functionality either as part of the gelator itself or by an external chemical stimulus such as a change in pH, or addition of molecules or ions that interact with the dynamic gel. Gels derived from LMWGs have been proposed in a range of applications and include templation of nanoparticles and nanostructures, drug delivery and wound healing and as crystal growth media.

This presentation focuses on a particular niche of tuneable LMWG chemistry, namely the use of concepts borrowed from anion host-guest chemistry to control and trigger the materials properties of small molecule (supramolecular) gels. We show how concepts firmly rooted in supramolecular host-guest chemistry and supramolecular self-assembly can be married with the materials science of soft matter in order to utilise a molecular-level understanding of supramolecular chemistry to control and manipulate bulk materials properties. This ‘evolution’ has been described in a recent review,² and the application of these kinds of switchable gels as novel media for pharmaceutical crystal growth has also recently been published.³ A picture of carbamazepine crystals growing in a LMWG organogel is shown right.

地点：教八218

时间：4月23号（星期一）上午9:30