▎ 摘　　要

NOVELTY - A conductive composite material is prepared by adding resorcinol, formaldehyde and sodium carbonate catalyst into aqueous solution of uniformly dispersed graphene and carbon nanotubes (CNT); reacting at 85 degrees C for 3 days to obtain graphene-CNT-resorcinol-organic formaldehyde gel; and performing high temperature carbonization after freeze drying to obtain low-density and high-specific surface area 3-dimensional graphene-CNT-carbon aerogel structure. USE - Method for preparing highly electrical conductive flexible composite material (claimed). ADVANTAGE - The method is capable of providing highly conductive flexible composite material. The graphene and CNT are free of agglomeration and good in dispersion. A bonding interface of conductive filler and polymer matrix is firm. The material obtains has low conductive filler content. DETAILED DESCRIPTION - Preparing composite material comprises: (A) adding resorcinol, formaldehyde and sodium carbonate catalyst at a mole ratio of 200:400:1-50 into aqueous solution of uniformly dispersed graphene and CNT; (B) ultrasonically dispersing, and reacting at 70-100 degrees C for 24-168 hours to obtain graphene-CNT-resorcinol-organic formaldehyde gel; (C) soaking the gel in water for 24-48 hours to remove unreacted small molecules; (D) performing high temperature carbonization in tubular furnace at 900-1000 degrees C after freeze drying at ~42 to ~26 degrees C for 48-72 hours to obtain low-density and high-specific surface area 3-dimensional graphene-CNT-carbon aerogel structure; and (E) taking the low-density and high-specific surface area 3-dimensional graphene-CNT-carbon aerogel structure as conductive skeleton for uniformly impregnating silicone rubber polydimethylsiloxane (PDMS) into the conductive skeleton by vacuum-assisted method. The CNT is acidified using concentrated nitric acid or sulfuric acid.