Fabrication Of Porous Graphene/Polymer Monoliths And Research Of Their Absorbility

With the development of industry and urbanization,water has been seriously polluted.Low cost,effective and environmental friendly absorption materials have attracted much attention.Porous materials have large specific surface area,low density,and high specific strength because of their porous structure.They are potential candidates as absorption materials.We fabricated a serial graphene/polymer porous materials employing freeze-drying and electrospinning respectively,and used them as absorption materials.In recent years,graphene has attracted a great deal of attention due to its excellent physical and chemical properties.Reduced graphene oxide（rGO）coated polyurethane sponges（rGPUS）were fabricated by a facile dip method.The compressive strength of rGPUS increased with the coating of rGO.rGPUS can selectively absorb oil from water surface due to their hydrophobility.For all the organic liquids tested,the absorption capacities of rGPUS were higher than 80 g/g and 160 g/g was achieved for chloroform,and the absorption equilibrium time is lower than 100 s.In addition,the absorption capacity of the rGPU sponge did not deteriorate after it was reused for 50 times.Therefore,the rGPUS has excellent recyclability.Biodegradable porous r GO coated chitosan（rGCS）and rGO/poly（lactic acid）（rGO/PLA）monoliths were fabricated by freeze-drying.The incorporation of rGO increased the hydrophobicity of the porous monoliths resulting in highly selective absorption for organic liquids.The maximum absorbility of porous r GCS and rGO/PLA monoliths were 52 g/g and 94 g/g respectively.rGO increased the compressive strength of the porous monoliths,so they could be recycled by centrifugation.After five cycles,the saturation sorption capacity remained at 80%of the original capacity.Cellulose from cloth waste is environmental friendly,widely abundant,and cheap.Graphene oxide/regenerated cellulose nanofiber membranes（GO/rCNFM）were prepared by electrospinning of blue jeans in ionic liquid.rCNFM were biocompatible,and can be used in transdermal drug release.GO/rCNFM immobilized with lysozyme have excellent anti-microbial activities for gram positive bacterias,such as S.aureus.In addition,GO/rCNMF and rGO/rCNMF were good sorbent for metal ions and organic liquids respectively.GO/carboxymethyl cellulse（GO/CMC）porous monoliths were prepared by a unidirectional freeze-drying method and used as adsorbents for metal ions.The adsorption capacity for Cu²⁺was 83 mg/g,and the adsorption investigated fitted to Langmiur isotherm model.After porous rGO/CMC monoliths were used to adsorb Ni²⁺,the monoliths were then treated with sodium borohydride to transform Ni²⁺to Ni nanoparticles.These Ni nanoparticle-containing porous rGO/CMC monoliths showed superior catalytic performance for the reduction of 4-nitrophenol.