SUSHYMAT

SUSHYMAT, for SUStainable HYbrid MATerials, will involve studying an original particle-polymer-complexing agent ternary system, based on the composition of the wall, in order to understand the mechanisms of interactions and formation of assemblies. The study will be both fundamental, under dilute conditions, and applied to the development of new materials; the addition of new functionalities by adding an inorganic component will also be considered. With a view to designing sustainable systems, the biodegradability of materials will be assessed.

While petrosourced plastics established themselves as revolutionary materials in the decades following their discovery, it has since become clear that they pose an environmental threat affecting various ecosystems. Consequently, replacing them with sustainable alternatives in large-scale applications such as packaging is urgent but remains a challenge due to their highly competitive properties and prices.

One alternative is to produce sustainable, biodegradable materials from biopolymers, as these can be obtained from biomass in large quantities, in a renewable way, while possessing intrinsic properties at least equivalent to those of synthetic polymers. Certain limitations of biopolymers, such as their sensitivity to water, prevent them from being used on a large scale, and require new approaches.

The aim of SUSHYMAT (Functional SUStainable Hybrid MATerials: elaboration and evaluation) is to develop a new generation of sustainable materials, hybrid or otherwise, with properties comparable or even superior to those of petroleum-based materials. Our approach to their development is based on the nanocellulose - hemicellulose - polyphenols ternary system, which mimics the composition of plant tissues and can give rise to original microstructures leading to synergistic properties. They can be advantageously transposed on a macroscopic scale into functional and biodegradable materials thanks to a well-controlled assembly process. In addition, polyphenols, which are well known to interact favourably with plant cell wall biomolecules and inorganic species, would favour interactions at the organic-inorganic interface, which could lead to new homogeneous hybrid materials with enriched properties.

The objectives are therefore both a fundamental study of the biomimetic ternary system of nanocellulose - hemicellulose - polyphenols in order to identify the interactions and mechanisms responsible for the structures formed, and the development of materials by self-assembly (hydrogels, films). Hybrid materials will also be studied by adding an inorganic component in a second, more exploratory stage. Finally, the biodegradability of the materials will also be put to the test through the development of ‘in-house’ biodegradability tests involving enzymatic cocktails, accelerated and focused on degradation in aqueous media in order to ensure that the materials prepared are virtuous.

SUSHYMAT is a JCJC ANR project led by Hugo Voisin, a researcher in the BIA Unit. The project involves three BIA research teams: the Nano team (Hugo Voisin, Isabelle Capron), PVPP (Estelle Bonnin) and PRP (Sylvain Guyot). SUSHYMAT began on 01 October 2023 and will end on 31 March 2027.

A PhD student, Sarah MAMDOUH, was recruited on 02 January 2024 to study the nanocellulose - hemicellulose - polyphenols ternary system with the aim of preparing biodegradable materials.

A postdoctoral student (12 months) will be recruited to characterise the action of enzymes on the materials developed during the ANR in order to determine their potential biodegradability, in particular the influence of polyphenols on this property.