Benefit of liquid crystal moieties in the MIP technique.

Several liquid crystalline imprinted materials have been synthesized from polysiloxanes or polyacrylates bearing mesogenic side-chains and low contents of cross-linkers. They were imprinted by various achiral or chiral templates, then tested for molecular recognition or assessed as specific catalysts. All mesogenic imprinted networks exhibit a much higher affinity towards the template than non-imprinted networks. On the other hand, the molecular trapping capacity was shown to be much greater than that of most of the previously studied non-mesomorphous systems. Moreover, it was shown that mesomorphic order provides significant enhancement to the bonding between the template and the liquid crystalline network and reinforces the shape memory of the imprinted cavities. Some of these materials were used to catalyze the isomerization of benzisoxazole. They exhibited an acceleration effect close to 100 between imprinted sites and non-imprinted ones. Lastly, cholesteric networks, that were imprinted by a chiral template, showed good properties for the enantiomer separation leading to an enantiomeric excess of 35% and a capacity of around 1 mmol g(-1).

First approach to the use of liquid crystal elastomers for chemical sensors.

Liquid crystalline thin films elastomers that are able to bind pesticides have been developed. The synthesis involves grafting mesogen and crosslinkable groups on a polysiloxane chain in the presence of a template molecule. The molecular imprinted material is obtained after thin film deposition, UV crosslinking and washing. Experiments of readsorption of pesticide are presented. Development of a multisensor platform based on thermal and capacitive sensors is described and tests of deposition of the polymer film are presented.