Biomimetic aerogels of small intestinal villi guided by biobased electrolyte ligands: High flame retardation, heat insulation, antibacterial and degradation performance

Inspired by the morphology of human intestinal villi and guided by principles of sustainability and efficiency, this study developed a bionic composite aerogel incorporating protonated polyethyleneimine-phytic acid ligands into an HPMC-MTMS cross-linked network. The aerogel exhibits an ultra-light density (about 0.03 g/cm 3 ), a 2.77-fold increase in specific surface area, and 99.24 % porosity. It achieves outstanding thermal insulation with a minimum thermal conductivity of 0.0319 W/(m·K) and effectively reduces surface temperatures during prolonged heating. Compared to pure HPMC-MTMS aerogels, it shows remarkable flame retardancy, with a Limiting Oxygen Index (LOI) of 30.2 %, reductions in Peak Heat Release Rate (PHRR) and Total Heat Release (THR) by 61.14 % and 58.21 %, respectively, and self-extinguishes within 0.03 s at 1200 °C. Additionally, the aerogel demonstrates robust antibacterial properties (94.36 % inhibition against E. coli and 82.10 % against S. aureus ) and rapid biodegradability, fully degrading in soil within 25 days. This innovative aerogel combines functionality and sustainability, highlighting its potential in advanced thermal insulation and fire-retardant applications.