Boron Nitride Aerogels with Super‐Flexibility Ranging from Liquid Nitrogen Temperature to 1000 °C

Abstract

Aerogels with extraordinary mechanical properties attract a lot of interest for their wide spread applications. However, the required flexibility is yet to be satisfied, especially under extreme conditions. Herein, a boron nitride nanoribbon aerogel with excellent temperature-invariant super-flexibility is developed by high temperature amination of a melamine diborate precursor formed by hydrogen bonding assembly. The unique structure of the aerogel provides it with outstanding compressing/bending/twisting elasticity, cutting resistance, and recoverable properties. Furthermore, the excellent mechanical super-flexibility is maintained over a wide temperature range, from liquid nitrogen temperature (−196 °C) to higher than 1000 °C, which extends their possible applications to harsh environments.

3D printing-directed auxetic Kevlar aerogel architectures with multiple functionalization options

“…29 The elastic region corresponds to the bending of the ANF nanobres, the relatively at plateau is attributed to the postbuckling deformation of the nanobres, and the rapid stress increase region is due to the densication of the various pores in 3D printed aerogels. 45,46 Therefore, the Kevlar aerogel woodpile structure with a density of 26.8 mg cm À3 could withstand a compressive load of 9.8 N (compressive stress of 28.9 kPa) at the critical compression strength (Fig. 2b).…”

An Organic Crystal with High Elasticity at an Ultra‐Low Temperature (77 K) and Shapeability at High Temperatures

“…Thecrystal was found to show elasticity not only at room temperature but also even in liquid nitrogen (LN 2 ). We note that some low-density and porous aerogels/foams based on inorganic boron nitride [36] or carbon materi- Figure 1. Elastic bending of the needle-shaped HMBPPA crystal at r.t. and 77 K. a) Chemical structure of HMBPPA.…”

Highly compressible and anisotropic lamellar ceramic sponges with superior thermal insulation and acoustic absorption performances

“…n recent years, various sponge-like materials, including carbon nanotube aerogels 1,2 , biomass-derived aerogels [3][4][5][6] , graphene aerogels [7][8][9][10][11][12] , ceramic nanofiber aerogels [13][14][15] , and carbon nanofiber aerogels [16][17][18] , have received significant interest owing to their high compressibility and resilience under large deformation, which results from their porous three-dimensional network structures. Among them, ceramic sponge materials have attracted more interest owing to their lightweight feature, high specific surface area, low thermal conductivity, and excellent chemical and thermal stability 13,14,19,20 . By virtue of these characteristics, ceramic sponge materials have been widely used in a variety of fields, including thermal insulation, water treatment, as catalyst carriers, for energy absorption, and for high-temperature air filtration 13,[21][22][23][24] .…”