Co-reporter:Kai Fan, Jianxi Huang, Haijun Yang, Runsan Lu, Xueqing Sun, Jun Hu, Zhengchi Hou
Journal of Membrane Science 2017 Volume 543(Volume 543) pp:
Publication Date(Web):1 December 2017
DOI:10.1016/j.memsci.2017.08.063
•Method of simultaneous γ-ray irradiation in homogenous phase.•Polyethersulfone membrane with pH-dependent permeability.•Polyethersulfone membrane with thermal-dependent permeability.Polyethersulfone (PES) and monomer methacrylic acid (MAA) were chosen to synthesize the grafted polymer PES-g-PMAA by simultaneous γ-ray irradiation in homogenous phase. Membranes prepared from pristine PES and PES-g-PMAA with different degrees of grafting (DGs), have been obtained. The kinetics of grafting reaction and the DG values were studied through sulphur elemental analysis. The morphology study of the membranes showed formation of sponge-like structure in the sub-layer of membrane, along with grafting PMAA onto the PES chains. By ultrafiltration experiments, a regular pH-dependent permeability and thermal-dependent permeability of PES-g-PMAA membranes was demonstrated through introduction of PMAA onto the PES which reduced the water flux of the membranes. The pH-dependent permeability could be attributed to pH-sensitive reconfiguration of PMAA molecule chains on the surface of membrane pore, while thermal-dependent permeability might be caused by better thermal-sensibility of PMAA chains inside the membrane.Download high-res image (221KB)Download full-size image
Co-reporter:Lifang Chen;Xiaofeng Lu;Peng Chen;Zhongying Liu;Liguo Shen;Xiaokai Bian;Qiang Qin
Journal of Applied Polymer Science 2013 Volume 128( Issue 6) pp:3949-3956
Publication Date(Web):
DOI:10.1002/app.38625
Abstract
Poly(vinylidene fluoride) (PVDF) powders were grafted with N-vinyl pyrrolidone using the pre-irradiation induced graft polymerization technique. The effects of reaction time, absorbed dose, and monomer concentration on the degree of grafting were investigated, and the grafted PVDF powders were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. The grafted PVDF powders were also cast into microfiltration (MF) membranes via the phase-inversion method. The contact angle and water uptake were measured. The membrane morphology was studied by scanning electron microscopy, and the water filtration properties of the membranes were tested. The antifouling properties were determined through measurements of the recovery percentage of pure water flux after the MF membranes were fouled with bovine serum albumin solution. The results confirmed that the existence of poly(N-vinyl pyrrolidone) (PVP) graft chains improved the hydrophilicity and antifouling properties of the MF membranes cast from PVDF-g-PVP powders. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Co-reporter:Qiang Qin, Zhengchi Hou, Xiaofeng Lu, Xiaokai Bian, Lifang Chen, Liguo Shen, Shuai Wang
Journal of Membrane Science 2013 427() pp: 303-310
Publication Date(Web):
DOI:10.1016/j.memsci.2012.09.059
Co-reporter:HaiJun Yang;Jun Hu
Journal of Applied Polymer Science 2012 Volume 123( Issue 4) pp:2266-2271
Publication Date(Web):
DOI:10.1002/app.34563
Abstract
The graft density and surface topography of ultra-flat polydimethylsiloxan films grafted with poly(acrylic acid) brushes by UV irradiation are investigated. The graft density keeps increase with the irradiation time and with the monomer concentration to a maximum, after which it remains unchanged in the former case or drops in the latter. Atomic force microscopy results show that a longer irradiation time, a higher monomer concentration and the addition of ethanol in the grafting solution are favorable to obtain the grafted polydimethylsiloxan films with flat surface. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Co-reporter:Chen Zhou, Zhengchi Hou, Xiaofeng Lu, Zhongying Liu, Xiaokai Bian, Liuqing Shi, and Liang Li
Industrial & Engineering Chemistry Research 2010 Volume 49(Issue 20) pp:9988
Publication Date(Web):September 17, 2010
DOI:10.1021/ie100199h
Polyethersulfones (PES) with three different molecular weights were chosen to prepare ultrafiltration (UF) membranes by the nonsolvent induced phase separation method using polyvinylpyrrolidone (PVP) and N-methyl-2-pyrrolidone (NMP) as additive and solvent, respectively. The effect of PES molecular weight on the structure and performance of the prepared asymmetric membranes was investigated by means of UF experiments, measurements of membrane thickness and porosity, scanning electron microscopy, and the measurement of bursting strength, given fixed PVP or PES concentrations. It was found that increasing PES molecular weight would lead to a larger pore size in the skin layer but lower membrane porosity, and would result in membranes with higher strength, higher permeability, and lower rejection. Based on the experimental data of PES molecular weight, ternary phase diagram, and cast solution viscosity obtained from gel permeation chromatography, cloud point titration, and coaxial cylinder viscometer measurements, respectively, the underlying causes of membrane structures were accounted for from the combined perspective of thermodynamics and kinetics and polymer aggregate dimensions.
Co-reporter:Zhengchi Hou;Shuang Chen;Kanglong Sheng
Journal of Applied Polymer Science 2007 Volume 103(Issue 3) pp:1570-1577
Publication Date(Web):8 NOV 2006
DOI:10.1002/app.25351
The graft copolymerization of acrylic acid onto low-density polyethylene films by simultaneous γ-ray irradiation was carried out. The effect of water and ethanol as grafting solvents on the distribution of grafted poly (acrylic acid) in the low-density polyethylene films was studied with optical microscopy observations of dyed and sliced samples and attenuated total reflection/Fourier infrared spectroscopy analysis. When no vigorous homopolymerization occurred, both polyethylene and poly(acrylic acid) existed in the grafted layer, and the thickness of the grafted layer and the poly(acrylic acid) concentration in the grafted layer increased with an increasing degree of grafting, regardless of the grafting conditions, the former increasing faster than the latter. In comparison with water as the solvent, in the absence of the inhibitor, homopolymerization could be suppressed to a certain degree in the ethanol solvent system, whereas in the presence of the inhibitor, obvious homopolymerization occurred at a lower monomer concentration, and both the degree of grafting and the thickness of the grafted layer were lower. Such differences could be explained by the chain transfer and the relatively low solubility of poly(acrylic acid) in ethanol. In addition, an experimental scheme using optical microscopy to observe the dyed and sliced polymers was optimized. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1570–1577, 2007
Co-reporter:Fengying Zhang, Zhengchi Hou, Kanglong Sheng, Bo Deng and Leidong Xie
Journal of Materials Chemistry A 2006 vol. 16(Issue 13) pp:1215-1221
Publication Date(Web):2006/02/10
DOI:10.1039/B517550J
The use of high-density polyethylene (HDPE) films grafted with acrylic acid by γ-ray irradiation as a template to control the nucleation and growth of calcium carbonate crystals was attempted. The morphology evolution of crystals formed from supersaturated calcium bicarbonate solution on the grafted HDPE films was observed by scanning electron microscopy, and the interaction between the formed crystals and the grafted HDPE films was revealed by Fourier transform infrared spectroscopy. Results of the characterizations proved that carboxylic acid functional groups on the grafted HDPE films significantly facilitated the heterogeneous nucleation of calcium carbonate crystals, and the distribution of the crystals was in congruity with that of the grafted carboxylic acid groups, as discovered by the atomic force microscopic images. It can be concluded that radiation-induced grafting, a method for functional modification of polymer surfaces, is also an effective means for studying biomineralization.
Co-reporter:Jianxi Huang, Haijun Yang, Min Chen, Te Ji, Zhengchi Hou, Minghong Wu
Polymer Testing (May 2017) Volume 59() pp:212-219
Publication Date(Web):May 2017
DOI:10.1016/j.polymertesting.2017.02.005
