Structure and properties of glycomaterials

The research developed in this team concerns the polysaccharides in the semi-crystalline solid state (cellulose, starch, chitin, etc.): their morphology, structure and intrinsic properties, their organization within natural organisms as well as their applicatibility potential in order to design new materials via their functionalization and / or their self-assembly and / or the development of new processes.

The team in september 2019


The rarefaction of fossil resources combined with the dramatic environmental consequences of petroleum-based materials has greatly accelerated the interest in developing new bio-based materials. Research in this area is a major societal issue to support the transitions in the context of fossil resources exploitation and the consequences of their future depletion.

Several polysaccharides are involved in the architecture of many organisms (terrestrial plants, algae, mushrooms, crustaceans, insects, etc.) within which they often appear in the form of semi-crystalline objects for which at least one of the dimensions is at the nanometric scale. The micro / nanocrystals of cellulose or chitin that can be extracted from biomass vary in size. They have attractive qualities (natural abundance, renewability, biocompatibility and biodegradability) and unique physical and chemical characteristics (lightness, chirality, marked anisometry of shape and anisotropy of properties). These crystals are participate to the mechanical properties of the organisms which synthesize them, but after extraction, they are also elementary bricks of choice for creating a new generation of advanced materials compatible with the concepts of sustainable development. They are found in many forms and names (nanocrystals, nanofibrils, microfibrils, whiskers, etc.). They have raised the enthusiasm of academic researchers but also from industries, as evidenced by the considerable increase in the number of publications and patents in the field over the past ten years. These objects, their extraction, characterization and physical or chemical modification, in their native environment or transformed into various materials (aerogels, nanocomposites, suspended complexes, thin films, etc.) are at the heart of SPG team's research.

Legend : Some objects at the heart of the SPG team’s research: wood cellulose nanofibrils (left) and nanocrystals (center), tunicate cellulose nanocrystals (right) (TEM - negative staining).

However, understanding their biosynthesis and structuring within natural organisms and the rational development of such materials based on (or containing) polysaccharide nanocrystals, requires increasing our fundamental knowledge of their structure at different lengthscales. The objective of the team is therefore to establish structure-property relationships according to a multiscale strategy by studying the structure, morphology and organization of these nanocrystals at the atomic, molecular, supramolecular or colloidal, and macroscopic scales.

Legend : The various lengthscales covered by SPG research

Our research relies on the tools and concepts from various scientific fields including crystallography, biophysics, soft matter, colloids, polymers and materials sciences, in combination with many advanced imaging and spectroscopy techniques, thermomechanical analysis and modeling: solid-state NMR, infrared spectroscopy, radiation scattering and diffraction (in particular on large instruments), electron and near-field microscopy, atomistic and coarse-grain modeling. These approaches concern various communities in the fields of polymers and soft matter as well as biochemistry and biology of these materials.

Nanoscale (2019), 11, 21767-21774, doi:10.1039/c9nr06044h
web only. Editor: Paulomi Majumder JEM: Clay
Chemical Society Reviews (2018), 47, 2609-2679, doi:10.1039/c6cs00895j

Voir aussi dans «The Teams»

Chemistry and Biotechnology of Oligosaccharides The CBO team's research focuses on the development of chemical and enzymatic tools for the production of glycans (oligo-, polysaccharides) and glycoconjugates Self-Assembly of Glycopolymers The objective of the research project is the development of synthesis strategies to precisely modify biosourced carbohydrates in order to bring new functionalities. For instance, some of the goals are to produce polysaccharide mimetics, electrospun glyco-nanofibers, self-assembled glyco-nanoparticles and thin films or carbohydrate coatings via surface biomimicry for a variety of applications: molecular recognition (sugars, proteins), biosensors, selective filtration, control released, drug delivery, new lithographic template (biodegradable saccharide mask), flexible electronics (conducting glycopolymers), etc. Structural and molecular glycobiology The structural and molecular glycobiology team aims to unravel the structure/function relationships of proteins with complex glycans such as glycoconjugates and polysaccharides. Its research is at the chemistry-biology interface with multidisciplinary expertise in bioinformatics, molecular biology, biochemistry and enzymology, X-ray protein crystallography, analysis of protein-carbohydrate interactions and molecular modeling methods. Its research activity is conducted along the following topics: -The biosynthesis of complex carbohydrates by glycosyltransferases (GTs). -The degradation of complex polysaccharides by Polysaccharide Utilisation Loci (PULs). -The recognition of glycoconjugates by lectins. -The structural analysis of oligo- and polysaccharides.