Papers by Author: Xiao Yu Hu

Abstract: A ball mill was used to mechanochemically modified Polyvinylchloride (PVC) powders. PVC membranes before and after mechanochemical modification were prepared at different dope solution temperatures 60°C. The modified PVC membrane was immersed in HCl solution, NaClO solution and NaOH solution, the permeation flux and mechanical properties of the PVC membranes before and after post-treatment were studied. The results showed that, modified PVC membrane owned good ability of resistance to acid and alkali, NaClO solution had a strong oxidizing, it generated the polar group made the surface of PVC membrane more hydrophilic, the permeation flux improved. The strong oxidizing of NaClO solution made the skin layer of PVC membrane more thinner, the tensile strength decreased.

Abstract: Poly (vinyl chloride) /poly (acrylonitrile) (PVC/PAN) hollow fiber membrane was prepared by phase inversion method and it was hydrolyzed in different NaOH solution concentration. After hydrolysis modified, the change of surface characteristic of the PVC/PAN hollow fiber membrane was described by Fourier transform infrared attenuated total reflection spectroscopy (FTIR-ATR) and water contact angle. Morphological structures of membranes were observed by field-emission scanning electron microscope (FESEM). Protein filtration was employed to evaluate the antifouling performance of the membrane. All these results demonstrated that PVC/PAN hollow fiber membrane modified by hydrolysis showed high permeation flux, good hydrophilicity and antifouling.

Abstract: In the present study, Polytetrafluoroethylene (PTFE) porous hollow fiber membranes were prepared by PTFE concentrated suspension with the mixture of Poly(vinyl alcohol) (PVA) and Sodium alginate as the fiber-forming carrier. Factors affecting PTFE membrane pore structure and mechanical properties were investigated. Results showed that, (1) the permeation and mechanical properties of the PTFE membrane were influenced significantly by the sintering condition, (2) Morphologies of membranes were observed by scanning electronic microscopy (SEM), fixed sintering state was aided to form the pore structure which was much different from the node-fibril network obtained by PTFE biaxial-stretching process.

Abstract: Interactions of polymer and solvent in a highly chemical crosslinked polystyrene (PS) and polymethyl acrylate (PMA) gels are investigated. Crystal thermo of the benzene in PS-benzene gels were analyzed using differential scanning calorimeter (DSC). It was noted that benzene molecules in the gels can be categorized into three types, which is free benzene, weak bonded benzene and strong bonded benzene. In average, one PS structure unit interacted with three benzene molecules in the gel system. The conformation of dichloroethane (DCE) in PMA-DCE gels was studied using Fourier transfer infrared (FTIR). In PMA-DCE gels, DCE molecule bonded with PMA chains in a trans mode through a hydrogen bond. And the amount of trans DCE molecules increased with the increase in concentration of PMA in the gel system.

Abstract: Chemical crosslinker polymer gels were synthesized in situ polymerization of monomers in solvents with crosslinkers. Results showed that the solvent content of the polymer gels depended on the types of solvents and polymers as well as the crosslinkers. The adsorption ability to aromatic organic molecules of the polymer gels was measured by treating tryptophan solution containing phenol and pyrene aqueous solution. The aromatic compounds can be removed completely and no further pollution to the original solutions.