Lotus Root-Like SiO₂ Nanofibers for High-Temperature Flexible Thermal Insulation

Abstract

Large-scale spinning of high-performance SiO2 porous nanofibers remains a pivotal challenge in facilitating their utilization for flexible thermal insulation purposes. Herein, massive spinning of SiO2 porous nanofibers was achieved through the solution blow spinning (SBS) process utilizing microemulsion polysiloxane solutions. Using MK siloxane polymer as the Si source, a solution characterized by high purity and excellent uniformity was obtained. Multicomponent spinnable microemulsion precursor was prepared by incorporating paraffin as the sacrificial phase, Span 80 and Tween 80 as surfactants, and polyvinylpyrrolidone as the spinning aid. Through optimization of the spinnable solution composition and SBS process parameters, high-speed spinning of paraffin/MK precursor nanofibers was accomplished with a rate of 20 mL·h–1. Subsequent high-temperature pyrolysis facilitated the conversion of organic paraffin/MK nanofibers into SiO2 nanofibers with controllable pores structure. Porous SiO2 nanofiber sponges fabricated using the microemulsion SBS technique exhibit distinctive lightweight and thermal insulation properties [0.037 W·(m·K)−1]. These properties promise to facilitate massive spinning of high-performance inorganic fiber sponges for applications in high-temperature thermal management.