Aerogel from sustainably grown bacterial cellulose pellicle as thermally insulative film for building envelope

TL;DR

This study develops sustainable bacterial cellulose aerogel films from beer brewing waste for building insulation, achieving low thermal conductivity and offering an affordable, eco-friendly retrofitting solution to improve energy efficiency.

Contribution

Introduces a novel, sustainable bacterial cellulose aerogel film derived from food waste, with optimized thermal properties for building insulation applications.

Findings

Achieved thermal conductivity as low as 13 mW/(K*m).

Used beer brewing waste as a cost-effective substrate.

Demonstrated potential for scalable, eco-friendly insulation materials.

Abstract

Improving building energy performance requires the development of new highly insulative materials. An affordable retrofitting solution comprising a thin film could improve the resistance to heat flow in both residential and commercial buildings and reduce overall energy consumption. Here we propose cellulose aerogel films formed from pellicles produced by the bacteria Gluconacetobacter hansenii as insulation materials. We studied the impact of density and nanostructure on the aerogels' thermal properties. Thermal conductivity as low as 13 mW/(K*m) was measured for native pellicle-based aerogels dried as-is with minimal post-treatment. The use of waste from the beer brewing industry as a solution to grow the pellicle maintained the cellulose yield obtained with standard Hestrin-Schramm medium, making our product more affordable and sustainable. In the future, our work can be extended through further diversification of the sources of substrate among food wastes, facilitating larger potential production and applications.