Monolithic carbon aerogels within foam framework for high-temperature thermal insulation and organics absorption

Kede Wu; Junxiang Cao; Zhen Qian; Yi Luo; Bo Niu; Yayun Zhang; Donghui Long

doi:10.1016/j.jcis.2022.03.087

Monolithic carbon aerogels within foam framework for high-temperature thermal insulation and organics absorption

J Colloid Interface Sci. 2022 Jul 15:618:259-269. doi: 10.1016/j.jcis.2022.03.087. Epub 2022 Mar 23.

Authors

Kede Wu¹, Junxiang Cao¹, Zhen Qian¹, Yi Luo¹, Bo Niu², Yayun Zhang³, Donghui Long⁴

Affiliations

¹ Shanghai Key Laboratory of Multiphase Materials Chemical Engineering, East China University of Science and Technology, School of Chemical Engineering, Shanghai 200237, PR China.
² Shanghai Key Laboratory of Multiphase Materials Chemical Engineering, East China University of Science and Technology, School of Chemical Engineering, Shanghai 200237, PR China. Electronic address: niubo@ecust.edu.cn.
³ Shanghai Key Laboratory of Multiphase Materials Chemical Engineering, East China University of Science and Technology, School of Chemical Engineering, Shanghai 200237, PR China. Electronic address: yy.zhang@ecust.edu.cn.
⁴ Shanghai Key Laboratory of Multiphase Materials Chemical Engineering, East China University of Science and Technology, School of Chemical Engineering, Shanghai 200237, PR China; Key Laboratory of Specially Functional Polymeric Materials and Related Technology, East China University of Science and Technology, Shanghai 200237, PR China. Electronic address: longdh@mail.ecust.edu.cn.

PMID: 35339962
DOI: 10.1016/j.jcis.2022.03.087

Abstract

Carbon aerogels exhibit high porosity, good electrical conductivity, and low thermal conductivity, but their practical applications are greatly hindered by their tedious preparation and inherent structure brittleness. Herein, monolithic carbon aerogels (MCAs) with low density and large size are prepared via a facile sol-gel polymerization of phenolic resin within melamine foam (MF), followed by ambient pressure drying and co-carbonization. During ambient pressure drying process, the MF matrix can deliver supporting force to counteract against the solvent evaporation surface tension, thus inhibiting volume shrinkage and shape deformation. Upon co-carbonization process, the MF matrix and organic aerogel could pyrolyze and shrink cooperatively, which could effectively prevent the brittle fracture of monolith. Therefore, large-sized MCAs (up to 250 × 250 × 20 mm) with low densities of 0.12-0.22 g·cm^-3 are obtained. The as-obtained MCAs possess high compressive strength (2.50 MPa), ultra-low thermal conductivity (0.051 W·m^-1·K^-1 at 25 °C and 0.111 W·m^-1·K^-1 at 800 °C), and high-volume organic absorption capability (77.3-88.0%, V/V). This facile and low-cost method for the fabrication of large-sized monolithic carbon aerogels with excellent properties could envision enormous potential for high-temperature thermal insulation and organics absorption.

Keywords: Carbon aerogel; High compressive strength; Monolith; Organics absorption; Thermal insulation.