Superflexible Multifunctional Polyvinylpolydimethylsiloxane-Based Aerogels as Efficient Absorbents, Thermal Superinsulators, and Strain Sensors

Abstract

Aerogels are attractive porous materials but usually show poor mechanical properties and limited functionality, which significantly restrict their practical applications. Preparation of highly bendable and machinable aerogels with multifunctionality still remains a difficult challenge. Here we report unprecedented superflexible aerogels based on polyvinylpolydimethylsiloxane (PVPDMS) network, PVPDMS/polyvinylpolymethylsiloxane (PVPMS) copolymer network, and PVPDMS/PVPMS/graphene nanocomposite via a facile radical polymerization/hydrolytic polycondensation strategy followed by low-cost ambient pressure drying or freeze drying. The resulting aerogels possess a doubly cross-linked organic-inorganic network structure consisting of flexible polydimethylsiloxanes and hydrocarbon chains with tunable crosslinking density, and exhibit tunable pore size and bulk density, high hydrophobicity, excellent machinability, and superflexibility against both compression and bending. More importantly, they show multifunctionality combining selective absorption, efficient separation of oil and water, thermal superinsulation, and strain sensing. This study is expected to provide new concepts to synthesize multifunctional materials with a wide range of potential applications in absorbents, superinsulators, sensors, wearable electronics, etc.