Nacre-Inspired Hybrid Multilayer Insulation Composites

Superinsulation aerogels are characterized by low tensile strength and brittleness due to their high porosity. To address these limitations, multiscale architectural design inspired by nacre can be employed. This materials design approach offers a promising strategy for enhancing the mechanical strength of aerogel thermal insulation. In this study, we present nacre-inspired multilayer cellulose-silica aerogel configurations. The cellulose "brick" network imparts structural strength to effectively redistribute energy, while the nanoporous "mortar" silica blocks heat transfer, maintaining insulation and fire retardance. The multilayer composites, with a layering configuration of five cellulose layers with four silica layers (5 + 4) and a cellulose layer thickness of 1.42 mm, exhibit a thermal conductivity of 31.3 mW/(m·K), a flexural modulus of 505 MPa, and an impact strength of 7.33 kJ/m². The hydrophobic composite shows a water contact angle of 127°, enhanced soundproofing with a 27% noise reduction, and a carbon footprint of 0.49 kgCO₂eq/kg. The multilayer cellulose-silica aerogel design provides a robust, eco-friendly thermal insulation solution for green building applications.