Designing elementary bricks to order

Controlling the structural variability of biopolymers, nanocrystals and nanofibres

We are studying the modification of hemicelluloses (xyloglucans, xylans, glucomannans, etc.) using physical (ultrasound) or enzymatic processes to modulate parameters such as molar mass or molecular structure (substitution rate and distribution of substituents in hemicelluloses, for example). In addition to native cellulose nanocrystals, other crystalline structures (cellulose II) are envisaged; we will also be looking at nanoparticles that vary in morphology (cellulose nanofibres) or surface chemistry (chitin nanocrystals/nanofibres).

Surface modification pathways for nanocelluloses

We are focusing on three strategies for modifying nanocelluloses: (i) physical adsorption of biopolymers (hemicelluloses with controlled structural variability), (ii) enzymatic modification (including LPMO enzymes, laccases, lipases, etc.), (iii) targeted regio-specific chemical functionalisation (surface or reducing end) using less energy-intensive and less toxic processes (simultaneous multi-functionalisation) in order to direct the modification towards the nanocelluloses. ), (iii) targeted regio-specific chemical functionalisation (surface or reducing end) using less energy-intensive and less toxic processes (simultaneous multi-functionalisation) in order to direct the modification towards high added-value objects such as programmable materials.

Hybrid particles

We combine nanoparticles of biological origin (cellulose or chitin) with a small fraction of other particles, generally inorganic, with specific properties accessible on the surface. The nanocrystals thus serve as substrates for the controlled nucleation and growth of nanoparticles such as Ag, TiO2, CuO, etc. This type of modification uses the principles of the Safer-by-design approach aimed at minimising risks to human health and the environment.