| A series of polymer inclusion membrane(PIM) were prepared by solvent evaporation method, and the composition and crystallization behavior of PIM was characterized and analyzed by FT-IR and XRD, respectively. Atomic force microscopy(AFM) and scanning electron microscope(SEM) were used to observe the microstructure of PIM, and the tensile testing machine was used to measured the mechanical properties of PIM. The transport experiments of phenol in solution through the prepared PIMs were carried to investigate the transport performance, separation conditions and practical appliance of the prepared PIMs.A PIM stemsy containing polyvinyl chloride(PVC) polymer matrix and bis(2-ethyl hexyl)-phosphoric acid(D2EHPA, P204), as a specific carrier, was prepared and marked as PD-PIM in the second chapter. The transport experiments of phenol through the PD-PIM were carried to investigate the transport performance of PD-PIM.The results showed that with the increasing of carrier content in membrane, the surface roughness and elongation at break of PD-PIM increase, the the degree of crystallinity and the tensile strength reduced. The transport experiments indicated that the transmission process of phenol was in line with the first order kinetics equation and the optimal transport process occurred with the membrane contained 70% D2 EHPA, from the source solution of phenol concentration was 400 mg·L-1 at p H 6.0, by using 0.1mol·L-1HCl as receiving phase. In addition, the permeability coefficient of PD-PIM was no significant down trend after 84 h transport experiment.The PIM containing PVC as polymer matrix and N,N-di(1-methylheptyl)acetamide(N503) as a specific carrier were prepared and used to investigate thefacilitated transport of phenol from model solution in the the third chapter. The results showed that the content of carrier in membrane had a significant impact on the microstructure and mechanical properties of PN-PIM. Due to the solvation of carriers,the surface morphology of PN-PIM ranged from smooth and homogeneous to fine polymer fibrous bundles with an increasing of carrier content in membrane. The transport of phenol was in line with the first order kinetics equation. The PN-PIM presented an optimal separation performance when the carrier content in membrane was68.8%, p H of feed solution was 2 and sodium hydroxide concentration of strip solution was 0.1 mol·L-1. The initial flux of the PN-PIM reached a maximum of 25.3 mg·m-2·s-1when phenol initial concentration was 8000 mg·L-1in feed solution. The thermodynamic analysis indicated that the transport of phenol through PN-PIM was the diffusion-controlled process. The PN-PIM still could keep a higher permeability coefficient(4.2 μm·s-1) after 60 h transport experiment, and the phenol in a large amount solution can be separated to the small amount of receiving solution by recycling separation. In the separation process of simulation phenolic resin industrial wastewater(phenol, formaldehyde mixture), the PN-PIM showed good selectivity for the separation of phenol.A PIM system with PVC as polymer matrix, N503 as carrier, and compositing a certain amount of graphene was prepared and marked as PNC-PIM in the fourth chapter.The effect of N503 and graphene contents on the microstructure and transport performance of the PNC-PIM were investigated, and the transmission mechanism of phenol in PNC-PIM was discussed. The results showed that the carrier content could be greatly enhanced by the addition of graphene in membrane, and then the separation performance of polymer inclusion membrane could be improved greatly. At the same separation conditions, the maximum permeability coefficient of PNC-PIM is almost twice the PN-PIM. The transport of phenol in membrane can divide into two continuous process: the transport through freedom carrier in membrane and pass through carrier in graphene. |
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