A simple and efficient method for preparing covalent organic framework aerogels with ultra-light and super-elastic

Abstract

In this paper, large-sized covalent organic framework (COF) aerogels were prepared using high-efficiency catalysis under room temperature combined with rapid gel and freeze-drying methods for the first time. Two kinds of COF aerogels with rigid and semi-rigid building blocks were prepared using this method, having good mechanical strength (126 and 106 kPa), elasticity (aerogels structure remains intact after 10 cycles), thermal insulation properties (low thermal conductivity of 0.03 wm −1 K −1 ), low dielectric constant (1 kHz of 1.21 and 1.51), thermal stability and solvent stability, and ultra-light characteristics (densities of 0.029 and 0.040 g cm −3 ). Compared to the traditional COF methods that generally result in small particles, the high-efficiency catalysis method developed in this paper can be used to prepare large-sized COF aerogels under mild reaction temperatures and within less time conducive to industrial production. This method is expected to greatly broaden the application field and application scope of COF materials. • Two COF aerogels were prepared combined with rapid gel and freeze-drying methods for the first time. • The COF aerogels behave good mechanical properties, thermal insulation properties, and ultra-light characteristics. • The method in this paper can be used to prepare large-sized COF aerogels under mild reaction temperatures and less time.