Multiscale modelling of the network formation in cellulose (aero)gels

Abstract

Within the framework of an ongoing project, lignocellulosic biowaste will be used to develop sustainable cellulose aerogels. A primary goal of the project is to develop a fundamental understanding of the network formation in such aerogels during their synthesis. While existing material models for biopolymer aerogels accurately predict their structure-property relations, they generally do not capture the gelation and its effect on their mechanical and thermal properties [1, 2]. To do this, discrete element method coupled with Langevin dynamics is chosen [3]. The cellulose polymer chains are first modelled using a structural model. Results from a density functional theory model are used as parameters in the mesoscopic model. The aggregation of the chains and fibres forming the three-dimensional (3-d) gel network are modelled using a functional model. The functional model further considers four models, viz., a diffusion model, an interaction model, a bond model, and a gelation model. These models and their consequent effect on modelling the gelation process in cellulose aerogels will be demonstrated and validated with experimental data. An outlook towards establishing relations between the gelation mechanism and the resulting mechanical properties will be illustrated.