Reinforced resorcinol formaldehyde aerogel with Co-assembled polyacrylonitrile nanofibers and graphene oxide nanosheets

Abstract

A three-dimensional organic aerogel nano-network with a high structural stability and strength was generated by the addition of polyacrylonitrile (PAN) nanofibers into a resorcinol-formaldehyde (RF) aerogel. The PAN solution was electrospun to produce PAN nanofibers. These were then oxidized to produce oxidized polyacrylonitrile (O-PAN) nanofibers. The two fibers were added to the RF nano-network to generate a hybrid RF aerogel, and so that the oxidization effect on the fibers could be observed. During the gelation process, the RF particles assembled themselves onto the surfaces of the electrospun PAN and O-PAN fibers. This increased the RF's structural stiffness, strength, and resilience. Then, the graphene oxide (GO) nanosheets were added to the mixtures to provide a cross-linkage between the fibers. This increased the number of RF particles on the fiber surface by an order of magnitude, as the interconnection between the fibers had been increased. This doubled both the strength and resilience of the final RF aerogels and tripled their stiffness. Meanwhile, their lightweight characteristics were maintained, and their thermal conductivities were below 30 mW/m.K.