Aerogel, known as a new material that changes the world, has excellent physical and chemical properties such as high porosity, large specific surface area, low density, and good thermal insulation properties. It is used in thermal / acoustic / electrical insulation, catalyst / drug carriers, interstellar dust collection, The fields of environmental restoration, energy and sensing have important application prospects. However, its own mechanical defects, such as weak strength, brittleness, and poor deformation ability, especially the ability to resist different load impacts in a wide temperature range, have become one of the most important obstacles to the practical application of aerogels.
In response to the above problems, the aerogel team led by researcher Zhang Xuetong of the Suzhou Institute of Nanotechnology and Nanobionics of the Chinese Academy of Sciences cooperated with German scientists to combine experimental design with theoretical calculations and regulate the hydrogen bond network through solvent components to find a simple, Efficient, green synthetic pathway, successfully prepared ultra-flexible boron nitride nanobelt aerogels, and achieved aerogel materials in a wide temperature range (-196 ° C ~ 1000 ° C) and different load impact forms ( Compression, bending, twisting, shearing, etc.).
Studies have shown that the boron nitride aerogel is made of ultra-thin (~ 3.2 nm), large aspect ratio (hundreds), and porous ribbon-like nanostructures intertwined and overlapped, showing ultra-light (~ 15 mg cm -3), thermal insulation (~ 0.035 W / mK), high specific surface area (~ 920 m2 g-1) and excellent mechanical properties. The aerogel can keep the structure from being damaged and can quickly return to the original shape under different loads such as compression, twisting, bending, and shearing under multiple cycles. When the aerogel is immersed in liquid nitrogen, its compression-resilience performance is still well maintained. Further, when the boron nitride aerogel is placed in the flame of an alcohol lamp or a tube furnace (air atmosphere) above 1000 ° C, its stable mechanical flexibility is still retained intact and can withstand the impact of different loads. The super-flexibility of the above boron nitride aerogel is shown below.
Figure, Boron nitride nanobelt aerogel under liquid nitrogen, flame, high temperature air atmosphere (> 1000 ° C), under flexible load-flexible deformation-rebound behavior.
The author believes that the obtained ultra-flexible boron nitride aerogel is expected to have practical applications in high-end fields such as aerospace thermal insulation and wave transmission, nuclear protection and thermal protection of nuclear reactors.