Preparation Of Graphene/PDMS Mixed Matrix Membrane And Its Pervaporation

The effective extraction and recovery of low concentration organic solvents is one of the key links in the industrialization.For the recovery of biofuels(butanol)and industrial wastewater(aniline and phenol),it is difficult for traditional separation to achieve the efficiency of environment friendly,energy saving and no secondary pollution effects because of their low concentration,volatility and toxiciy.Pervaporation is an effective alternative separation method for the traditional separation methods.Especially for the separation of low concentration and toxic organic matter,pervaporation technology shows the characteristics of environment friendly,energy saving and high efficiency.The purpose of this study is to improve the separation efficiency of butanol,aniline and phenol by preparing graphene/PDMS mixed matrix membrane.Graphene oxide,graphene and mixed matrix membranes were characterized by FT-IR,XRD,EDS,SEM,AFM,N2 adsorption-desorption and water contact angles respectively.The results of the study are as follows.1.EDS and FT-IR showed that the reduction temperature could control the reduction degree of graphene.The N2 adsorption-desorption showed that graphene had porous structure and high specific surface area(446.8 m2·g-1).The results of water contact angle showed that graphene could enhance the hydrophobicity of the membranes.2.The effect of reduction degree of graphene on the pervaporation performance of butanol was studied.The results showed that in the 1.5 wt%butanol/water solution,the reduction temperature was 700 ?,the PSI value reached the highest.The membrane flux was 910.5 g m-2·h-1,and the separation factor was 44.5.Compared with GO/PDMS membrane,the separation factor increased by 12.5%and the flux increased by 54.7%.It is proved that hydrophobic interaction of graphene are the main reasons for selective separation of butanol.3.The effect of reduction degree of graphene on the pervaporation performance of phenol was studied.The results showed that in the 0.5 wt%phenol/water solution,the reduction temperature was 900 ?,the PSI value reached the highest.The membrane flux was 460.2 g m-2·h-1,and the separation factor was 20.8.Compared with the GO/PDMS membrane,the separation factor increased by 103.7%.It is proved that hydrophobic interaction,large specific surface area,porous structure and ?-? covalent bond are the main reasons for selective separation of phenol.4.The effect of reduction degree of graphene on the pervaporation performance of aniline was studied.The results showed that when the reduction temperature was 700 ? in the 0.5 wt%aniline/water solution,the PSI value reached the highest.The membrane flux was 629.8 g m·2·h-1,and the separation factor was 54.2.Compared with the GO/PDMS membrane,the flux increased by 67.0%,while the separation factor was almost the same.It is proved that hydrophobic interaction,large specific surface area,porous structure and n-n covalent bond are the main reasons for selective separation of aniline.