Natural materials are ubiquitous in our daily environment, where they are exposed to environmental conditions like temperature and relative humidity variations. In particular, cellulose-based materials from plant origin have been used, and are particularly attractive nowadays as they offer sustainable solutions and as they can be a source of inspiration for biomimetic design of new materials. Wood, an orthotropic cellular biomaterial, displays remarkable properties combining low weight, high strength and high toughness, originating from a hierarchical organization of crystalline and amorphous polymers in its fiber's cell walls. Wood has the capacity of adsorbing water molecules from the surrounding environment into its hierarchical material structure which affect its mechanical properties as it has been reported in several studies at macro and micro scales. There is however a lack of information at the nanoscale, limiting the understanding of their hygromechanical properties. In this study, using model wood-polymer based films and wood-materials we are investigating at nanoscale the effect of water on the hygromechanical behavior of moisture-sensitive cellulose-based materials. To answer these questions, Atomic Force Microscopy-related methods, allowing nanomechanical and nanochemical measurements have been used to study the role of the different wood polymers on the hygromechanical behavior of pure or composite, mixed or layered bioinspired assemblies and compared with the natural material, i.e. wood secondary cell wall. Noteworthy, our experimental method allows us to perform AFM nanomechanical measurements under controlled relative humidity with a continuous monitoring of the same area. Such experimental characterizations will provide relevant information to develop molecular dynamics investigations. Combining in-vitro and in-silico investigations should allow a better understanding of the hygromechanical behavior lignocellulosic polymers for support the design of nanostructured bio-based material.

Nanoscale investigations of water effects on wood-inspired polymeric systems

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.