Imbibition and deformation of hygroscopic fibrous media – DeFHy

This project deals with the study of smart porous materials that react to environmental conditions (e.g. humidity). These materials are widely present in nature and engineered systems. However, this is an area where little systematic research has been done. We thus aim at studying model systems in order to understand the fundamental mechanisms underlying the liquid transport and mechanical properties of such responsive media. We will focus on fibrous media, in particular considering fibers that can swell when immersed in a solvent or placed in a humid environment. The main system we will consider is multi-component fibers, in which each component has a different swelling expansion. Such fibers will thus deform when “actuated”, i.e. swollen. We especially want to study the properties leading to large 3D deformation (coiling) in opposition to pure bending. These fibers will then be integrated into model fibrous media. We expect to observe changes in mechanical and liquid transport properties under different environmental conditions, which could lead to the design of new adaptive materials.