1- New supported ionic liquid phase (SILP) catalyst using biopolymer as support
This project aims to assemble the expertises of two partners : I. Dez who is specialised in the preparation, modification and characterization of biopolymer sciences, and A.C. Gaumont in homogeneous catalysis and ionic liquids synthesis.
In this work, we have developed new catalytic materials based on a biopolymer and an ionic liquid as supported liquid phase catalysis. This system is a mix between homo and heterogeneous catalysis. Although the final material is a solid, the active species in the liquid phase acts as a homogeneous catalyst preserving the high activity and selectivity and favouring the recovery and the reuse of the catalyst. We selected as support, chitosan, a natural biopolymer issued from the biofeedstock and obtained by partial deacetylation of chitin; or alginate, polysaccharide issued from brown alguae. The main advantages of these biopolymers is due to their abilities to be conditioned under beads, scaffolds or films... .
These new catalytic materials have been used with success in the Palladium catalyzed Tsuji-Trost allylic substitution. The crucial influence of the conditioning and the drying process of the chitosan support on the catalyst's activity and selectivity have been reported.
Further studies dealing with the exploration of the behaviour of these biopolymer-SILP catalysts for more challenging reaction such as olefin metathesis or the metal catalysed C-P cross-coupling, are currently under process.
2- Preparation of chitosan based biomaterials
In this work, we have developed new biomaterials based on a chitosan. Since chitosan appears to be a good candidate for wound-dressing, for soft tissue regeneration or drug delivery system, we have investigated the interactions between chitosan and cutaneous cells, such as keratinocytes and fibroblasts. The biopolymers were modified by different groups such as phosphorus functions, PEG...and their effects on the biological properties of chitosan films and on the swelling properties of films and scaffolds were evaluated. These studies have showed that the different chitosan derivatives have an excellent biocompatibility.