Electrostatic assembly of MOF-TiO2 frameworks and hollow structures for the preparation of ultra-thin thermally-insulated aerogels via electrospinning

Abstract

The increasingly severe situation of carbon emissions has led to an increasing emphasis on thermal insulation materials in energy conservation and environmental protection. Aerogels are an excellent type of excellent thermal insulation material, but its anti-infrared ability and the randomness of the pores limit its thermal insulation ability. This work utilized the unique hollow structure of MOF after heat treatment and the flexibility of MXene to prepare cubic-hollow Fe2O3-TiO2-SiO2 aerogels (CH-SiO2) with cubic inner pores through a combination of electrostatic assembly and electrospinning. The cubic pores in Fe2O3 efficiently impede heat-transfer; meanwhile, the special infrared shielding properties of TiO2 and Fe2O3 further reduce the influence of thermal radiation on the aerogel; additionally, introduction of TiO2 reduces the pore size and decreases the thermal convection in the heat transfer process. The synergistic effect of these three components results in its ultra-low thermal conductivity, of which the in-plane and through-plane thermal conductivities are 21 mW·m−1·K−1 and 315 mW·m−1·K−1, respectively. Finally, the excellent catalytic performance of CH provides ideas for the moisture resistance of composite materials.