General context: Cellulose is a natural polymer of beta-D-glucopyranose covalently linked through beta-1,4 linkages. Cellulose is naturally produced in large scale by living organisms and is used since a long time for the production of fibers or paper. Its polysaccharide structure confers to cellulose promising properties for the production of industrially valuable bio-based materials with a high potential of market in the field of surfactants, glues, thickening agent, viscosity modifier, to mention few. Nature has however designed cellulose as a robust polymer making its chemical processing rather complex for such application. Notably, the hydrogen bond network of cellulose, Van der Waals interactions and electronic effects represent important obstacles in the chemical processing of cellulose. CELLOPLASM aims at investigating the production of glucans from cellulose using non-thermal atmospheric plasma. Glucans are poly- or oligosaccharides made of glucosyl units that are connected through different types of glycosidic linkage (alpha/beta 1,4, 1,3, 1,6, 1,2). Although there exist few success stories for breaking down cellulose to a glucose juice (with the aim of producing low value chemicals), few barriers remain for the production of glucans from cellulose such as sugar concentration, separation and purity. Scientific hurdles: Acid catalysts are not adapted in the production of glucans from cellulose because they enhance side reactions that have similar apparent activation energy than the (de)polymerization reaction (e.g., successive intramolecular dehydration). Generally, biocatalysts are preferred. However, enzymatic routes suffer from a high dilution ratio (and sometimes low productivity) which impact the price of downstream processing and thus that of glucans. In this field, improvement of technical, economic and environmental impact still remains a top priority. Previous results and opportunities: Recently, pioneer works at IC2MP has revealed that non-thermal atmospheric plasma (NTAP) can produce concentrated feed of processable glucans with high purity directly from cellulose and under dry conditions. NTAP not only induces depolymerization but also repolymerization reactions. Interestingly, these repolymerization reactions occur in a random way yielding soluble and thus processable glucans. To the best of our knowledge, NTAP has never been deployed for the production of processable glucans from cellulose. We do believe that in this field, NTAP can potentially improve profitability through increase of reaction yield/selectivity, decrease of reaction times and the reduction of solvent waste. Project objectives: Few issues need to be addressed at the moment to (1) finely control the macro- and molecular structure of glucans produced by NTAP and (2) to determine the application domains this technology may support. To this end, the scientific strategy of CELLOPLASM relies on two main sections: 1) A deep investigation of the mechanism at play during the NTAP treatment of cellulose. To this end, the collection of data from three different domains is proposed (1) NTAP experiments, (2) glucans characterization and (3) quantum modelling 2) The application domain, in terms of business capabilities, the NTAP technology may support. The potential of the NTAP technology will be thus considered in the production of (i) glucans that are bio-based materials with a market price higher than 5-10 €/kg and (ii) alkyl glycosides which are biosurfactants with a lower value (1.5-2 €/kg) than glucans. Consortium: To reach the main deliverables of CELLOPLASM, a collaborative research with partners with different and complementary scientific expertise is proposed: (1) IC2MP (CNRS, Cellulose processing/NTAP/catalysis/modelling), BIA (INRA, polysaccharide characterization) and (3) ICR (Spanish National Research Council, glycoscience).

Currently, intense research efforts are made towards the discovery of innovative catalysts. Among the strategies used, catalysts that can be tuned by non-covalent interactions are more and more investigated. Such supramolecular catalysts are designed in the aim of modifying the second coordination sphere of a metal center; an unsolvable challenge with classical covalent metal-catalysts. Up to now, most of the supramolecular catalysts are built by means of electrostatic interactions or metal-ligand bonds which are poorly dynamic. Moreover, the architectures developed so far are difficult to modulate because their functionalization requires tedious synthetic steps. Finally, these systems are not reversible due to the fact that their chemical or catalytic properties are not modified by changes of their environment. Here, we describe how nanotubes and nanohelices, based on the hydrogen-bonded assemblies of bis-ureas and benzene 1,3,5-tricarboxamide (BTA) monomers, can constitute a new class of supramolecular catalysts. These assemblies are dynamic (since based on hydrogen bonds), functionalizable (by simple chemical modification of the monomer) and reversible (their architecture varies according to the concentration and the temperature among other parameters). By means of these unique properties, we will demonstrate that the self-association can be used to modulate the electronic, steric and chiral properties of a metal catalyst. Our catalysts will be statistical copolymers including phosphine-functionalized and classical bis-urea or BTA monomers. We plan to apply this system in three catalytic reactions: the asymmetric hydrogenation of olefins, the hydroformylation of olefins and the carbonylation of epoxides. In all cases, the same ligands will be used and a common d8-catalytic resting state will be involved in all the catalytic experiments. An additional feature of our system is the possibility to design an allosteric catalyst i.e. with catalytic properties that can be modified along the time by adding a cofactor or modifying the environment. The properties of these nanotubes and nanohelices (reversibility, dynamism and functionalization) and their use for the construction of several types of catalysts will constitute a breakthrough in the domain and thus deserve an urgent and intense investigation.