Polysaccharide-based aerogels for thermal insulation and superinsulation: An overview.

To reduce energy losses due to the insufficient thermal insulation is one of the current "hot" topics. Various commercial porous materials are used with the best conductivity around 0.03–0.04 W/(m·K). Aerogels are the only known materials with "intrinsic" thermal superinsulating properties, i.e. with thermal conductivity below that of air in ambient conditions (0.025 W/(m·K)). The classical thermal superinsulating aerogels are based on silica and some synthetic polymers, with conductivity 0.014–0.018 W/(m·K). Aerogels based on natural polymers are new materials created at the beginning of the 21st century. Can bio-aerogels possess thermal superinsulating properties? What are the bottlenecks in the development of bio-aerogels as new high-performance thermal insulationing materials? We try to answer these questions by analyzing thermal conductivity of bio-aerogels reported in literature. • Thermal conductivity of bio-aerogels is analysed. • Correlations between thermal conductivity and aerogel density and surface area are built. • A special focus is made on thermal conductivity below that of air. • Prospects of using bio-aerogels for thermal insulation are discussed. [ABSTRACT FROM AUTHOR]