Graphene Composite Oil Absorption And Separation Functional Materials

Graphene,a two-dimensional sheet of covalently bonded carbon atoms,it owned outstanding properties,including high electrical conductivity,mechanical flexibility,thermal conductivity and hydrophobicity-oleophilicity.In this paper,a series of graphene composite oil-absorptive and separation functional materials were prepared based on the hydrophobic-oleophilic property of graphene.Firstly,poly(n-butyl methacrylate)/graphene composite oil-absorptive material(Ge-PCt)was prepared by the non-solvent diffusion method and freeze-dired method,the morphology,hydrophobicity-oleophilicity and mechanical property of as-fabricated materials were investigated respectively.Ge-PCt exhibited hydrophobicity and superoleophilicity,water contact angel was up to 128.9° and kerosene contact angel was nearly 0°.Compared to cotton,the mechanical property of Ge-PCt had a slightly decrease.While Ge-PCt was placed in a oil/water separation device and treated by oil/water mixture,Ge-PCt was competent for continuous oil/water separation through gravity driven.Secondly,Nonwoven fabric reinforced polyvinylidene fluoride(PVDF)/graphene(GE)oil-absorptive composite membrane(NR-PGM)was prepared by coating method.NR-PGM was consisted of PVDF/GE separation layer and polyethylene terephthalate-polyamide nonwoven fabric matrix layer.PVDF/GE separation layer was obtained by non-solvent induced phase separation(NIPS)method with PVDF as polymer matrix,hydrophobic SiO2 and GE as additive,dioctyl phthalate(DOP)as pore-forming agent,and dimethylacetamide(DMAc)as the solvent.the morphology,hydrophobicity-oleophilicity and mechanical property et,al were investigated respectively.And effects of PVDF concentration in casting solution on the membrane characteristic was investigated.Results shows that NR-PGM exhibited hydrophobicity and superoleophilicity,water contact angel was up to 95.4° and kerosene contact angel was nearly 0°,water entry pressure was up to 0.14MPa and the kerosene flux reached 118.22 L/m2h.the thickness and water entry pressure were increase while kerosene flux decreased with PVDF concentration in casting solution increasing.Furthermore,oil-absorptive membrane hollow tube(OM-T)and oil-absorptive membrane hollow tube unit(OM-U)were fabricated,they could competent for continuous oil/water separation through vacuum pressure,the oil/water separation efficiency were up to 97.6%and 95.1%respectively,After being used for 10 times,the oil/water separation efficiency remained above 95%and 90%respectively.At last,graphene based polyurethane sponge(P-GPU)was prepared by dip-coating method which dipping polyurethane sponge into graphene suspension in ethanol,the graphene coated sponge was dipped into a dilute solution of polydimethylsiloxane in xylene for better interface bonding.the morphology,hydrophobicity-oleophilicity and oil-absorption capacity et,al of P-GPU were investigated respectively.Results shows that P-GPU exhibited hydrophobicity and superoleophilicity,water contact angel was up to 140.3° and kerosene contact angel was nearly 0°,the absorption capacities of P-GPU was higher than 20g/g for all tested oils.Furthermore,graphene based polyurethane oil-absorptive sponge hollow tube(P-GPU-T)and graphene based polyuethane oil-absorptive sponge hollow tube unit(P-GPU-U)were fabricated,they could competent for continuous oil/water separation through vacuum pressure,the oil/water separation efficiency were up to 96.6%and 96.4%respectively,After being used for 10 times,the oil/water separation efficiency remained above 94%and 93%respectively.