Aggregation-induced microfilaments enabled cotton cellulose aerogels with highly compressive and fatigue resistance, greatly thermal insulation and fireproofing.

Green and sustainable cellulose aerogels have attracted extensive attention, but are severely limited by unsatisfied elasticity, fatigue resistance as well as fire hazard for functional applications. Herein, we proposed a novel and feasible strategy to fabricate highly elastic, thermal insulating and fireproof phytic acid/cellulose (PA/CE) aerogel via constructing microfilament substructure derived from PA-induced aggregation and assembly of cellulose chains. Benefiting from the interconnected fibrous cellular walls integrating with abundant microfilaments, the resultant PA/CE aerogels demonstrated excellent compressibility and resilience with recovery rate of 91.26% after 100 compressive cycles at 50% strain. With the hierarchical porous structure, PA/CE aerogels exhibited low thermal conductivity of 0.0340–0.0352 W/m·K, could maintain its structural integrity and high temperature thermal insulation after heat treatment for 30 min at 400 ℃. Moreover, the integration of PA enabled aerogel high fireproofing with limiting oxygen index (LOI) of 42.6% and UL-94 V-0 rating. The peak of heat release rate (PHRR) and total heat release (THR) of PA/CE aerogels were 79.97 kW/m2 and 1.75 MJ/m2, reduction by 43.0% and 46.5% compared with cellulose aerogels. Thus, the elastic cellulose aerogels proposed by this strategy provide an insight and feasibility for high performance and multifunctional applications. [Display omitted] • PA-induced aggregation and assembly of cellulose chains was proposed. • The resulting PA/CE aerogels had hierarchical porous structure with plentiful microfilament substructures. • The aerogels displayed excellent compressibility and fatigue resistance with recovery rate of 91.26% after 100 compressive cycles. • The aerogels possessed high temperature thermal insulation with structural integrity bearing heat treatment at 400 ℃ for 30 min. • The aerogels showed high fireproofing with 43.0% and 46.5% reduction of PHRR and THR compared with CE aerogels. [ABSTRACT FROM AUTHOR]