Design & engineering of wood-inspired super-insulating foams

Abstract

Buildings account for 40% of the total U.S. energy consumption. The energy lost through building's walls, roofs and windows is the largest single waste of energy in most buildings. One way to contribute to the building energy efficiency consists in improving their thermal insulation by e.g., developing green and advanced functional materials as insulating panels. With the advent of the Green Economy, the use and valorization of lignocellulosic biomass as a possible alternative of fossil resources is a promising approach for elaborating low cost and high value-added insulation materials. Proper deconstruction or fractionation of cell wall components has indeed been reported to facilitate the development of a wide range of high value materials. The extraction of high aspect ratio cellulose nanomaterials (CNMs) or nanocelluloses, from e.g., wood cell walls, is especially creating a revolution in biobased materials for diverse applications such as packaging, cosmetics, automotive and electronics, owing to their low density, large surface area, and high strength-to-weight ratio. I will present our latest research on heat transport of fully bio-based foams and their thermal response as a function of relative humidity. The deconstruction of wood cell wall into cellulose nanofibers (CNFs) lays the foundation for the production of high-performance bio-based foams. I will discuss two engineering approaches to manufacture super-insulating foams: 1- the influence of chemical surface modification of CNFs on heat transfer of subsequent foams, and 2- the nature-inspired assembly of unmodified CNFs with another wood-biopolymer namely lignin, for enhanced performance. This presentation aims to share an insight on the potential of wood-based foams as thermal insulation materials, but also to inspire scientists, researchers, and future generations to exploit the biomass beyond traditional end-use products, such as for the engineering and manufacturing of sustainable advanced functional materials for energy transfer, storage, or conversion.