Preparation of elastic graphene aerogel and its adsorption of oil

Graphene aerogel with good mechanical properties and elasticity were extensively investigated for oil adsorbent. Herein, polyvinyl alcohol-graphene aerogel was prepared using Pickering emulsion method with polyvinyl alcohol being used as crosslinking agent and ethylenediamine (EDA) was used as reductant. The droplets of the Pickering emulsion played the role of soft templates during the aerogel preparation, and the droplets size was adjusted by adding different amount of butanol. When the content of EDA increases from 0.5 to 0.9%, the volume of aerogel gradually increases and its outer surface becomes smoother. However, when the content of EDA reaches 1%, aerogel becomes smaller and the outer surface becomes coarser. It was found that the compression stress and EDA content are positively correlated by simple manual extrusion. Compression-rebound test and Young's modulus calculation results indicated that the mechanical properties of aerogel can be effectively influenced by pre-freezing process. The fold degree of the wall, the maximum stress and Young's modulus of the aerogel increase gradually when prolonging pre-freezing time. The polyvinyl alcohol-graphene aerogel prepared by pre-freezing for 48 h with a density of 5.07 mg cm−3, a porosity of up to 99.8%, and a pore volume of 196.84 cm3 g−1 achieved instantaneous adsorption of oil slick on water. And the pore occupancy reached 93.31% under the saturated adsorption state on pure oil.