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紫外接枝聚合聚乙二醇甲基丙烯酸甲酯制备抗污染聚砜超滤膜 总被引:1,自引:0,他引:1
以二苯甲酮(BP)为紫外引发剂,将聚乙二醇甲基丙烯酸甲酯(PEGMA)接枝在聚砜超滤膜表面以提高膜的抗污染性能.在二苯甲酮存在的条件下,波长较长(λ300nm)的紫外光(UV)辐射下发生提氢反应,可以有效防止聚砜分子主链的剪切,保持改性膜的分离性能.考察了PEGMA浓度、UV辐射时间和BP浓度对改性超滤膜接枝度、亲水性和抗污染性能的影响.用表面全反射红外光谱(ATR/FTIR)表征改性前后膜表面化学组成的变化.表面改性膜的纯水通量略有降低而牛血清白蛋白(BSA)截留率有所提高.随着接枝度的提高,PEGMA接枝改性膜的抗污染性能增加. 相似文献
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使用四乙基氢氧化铵(TEAH)液相本体改性聚偏氟乙烯(PVDF), 以过氧化苯甲酰(BPO)为引发剂, 将丙烯酸(AA)接枝到改性PVDF骨架上, 合成了聚偏氟乙烯接枝聚丙烯酸(PVDF-g-PAA)共聚物, 通过浸没沉淀法制备了PVDF-g-PAA亲水性油水分离膜. 通过傅里叶变换红外光谱(FTIR)、 扫描电子显微镜(SEM)和过滤试验分析了膜的结构和分离性能. 研究了不同接枝条件对PVDF-g-PAA膜接枝率的影响. 同时, 通过膜接枝率与膜表面接触角的关系确定最佳接枝条件. 结果表明, TEAH使PVDF脱去HF产生碳碳双键且PAA接枝到改性的PVDF骨架上, 膜内外孔隙分布均匀; PVDF-g-PAA膜的接触角随着接枝率的提高而降低. 接枝单体AA含量为45%, 接枝温度为85 ℃, 接枝4 h制备的PVDF-g-PAA膜的接枝率为20.1%, 孔隙度为65.3%, 平均孔径为78.0 nm, 接触角为57.5°, 且在60 s内接触角降至14.3°; 纯水通量提高到571.33 L/(m2·h), 截留率和水通量恢复率分别达到94.3%和88.7%, 且通量衰减率仅为9.8%. 与纯PVDF膜相比, PVDF-g-PAA膜的分离性能显著提高. 相似文献
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UV辐照接枝制备酚酞基聚芳醚酮纳滤膜——链转移剂的作用 总被引:1,自引:0,他引:1
酚酞基聚芳醚酮(PEK-C)超滤膜的表面通过紫外辐照接枝丙烯酸(AA)可以制备对II价盐有很好截留率的亲水性纳滤膜. FTIR-ATR、表面接触角、SEM和AFM的研究结果表明, 在接枝单体溶液中加入异丙醇(i-PrOH)作为链转移剂并不影响AA在PEK-C超滤膜表面的接枝反应. 得到的改性膜同样具有优良的纳滤性能. 与不加i-PrOH的AA改性膜相比, 新合成的膜有较高的滤出液通量, 该膜对盐离子的截留率虽有所降低, 但可以通过增加接枝反应时间和辐照光源的强度来提高. i-PrOH的浓度对膜的分离性能的影响很大, 在低浓度时, 改性膜对离子的截留率会有所下降, 继续提高i-PrOH的浓度, 膜的截留率不再变化而滤出液通量会有成倍的增加, 表明链转移剂的存在可能会提高膜的接枝密度, 增加膜的表面电荷, 使膜对离子的截留率保持不变. 相似文献
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在水溶液中将聚六亚甲基单胍盐酸盐(PHGH)共价接枝在经多巴胺自聚合改性的聚砜膜表面, 制备具有抗菌性能的纳滤膜. 采用全反射红外光谱(ATR-FTIR)、 扫描电子显微镜(SEM)和接触角测试考察膜表面的结构、 形貌和亲水性变化. 探讨PHGH含量对膜的接枝度及分离性能的影响, 并对膜的抗菌性能进行了评价. 结果表明, 经过多巴胺的自聚合和表面接枝PHGH后, 聚砜膜表面形成了具有纳滤分离性能的活性层, 并且膜表面亲水性得到改善. 随着PHGH含量的增大, 膜的纯水通量降低, 而对无机盐和染料的截留性能提高. 接枝后的复合膜具有较高的抗菌性能, 当PHGH含量为3%(质量分数)时, 抗菌率可达98.5%. 相似文献
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《Journal of membrane science》2002,209(1):283-292
Surface modification using grafting of a hydrophilic polymer onto the membrane surface is a possible route to improving the fouling properties of polyamide thin-film composite membranes. The structure of nanofiltration (NF) and reverse osmosis (RO) membranes modified using graft polymerization of acrylic (AA) monomers was visualized and analyzed using attenuated total reflection–Fourier transform infrared spectroscopy, atomic force microscopy and transmission electron microscopy. The results show that a layer of AA polymer is indeed formed on the polyamide surface, which could be accompanied by a change of the surface morphology. It was observed that for the NF membranes studied polymerization could also take place inside the pores of the support as a result of penetration of the monomer through the active layer, particularly for high degrees of grafting. It suggests that the modification procedures should be optimized so that the latter effect is minimized. 相似文献
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《Journal of membrane science》1998,139(2):175-181
Radical grafting of two monomers, methacrylic acid and polyethylene glycolmethacrylate, onto commercial composite polyamide reverse osmosis membranes was performed. A redox system was used for initiation, and grafting was performed in an aqueous medium at room temperature. Surface grafting was characterized by ATR-FTIR, ESCA and streaming potential measurements. It was found that the membranes were surface modified without damage to their transport properties. 相似文献
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Natalya Nosova Yuri Roiter Volodymyr Samaryk Sergiy Varvarenko Yuri Stetsyshyn Sergiy Minko Manfred Stamm Stanislav Voronov 《Macromolecular Symposia》2004,210(1):339-348
Method of polyolefin surface activation via covalent grafting of polyperoxide nanolayer by free radical mechanism has been presented. The features of such the nanolayer formation under the thermoprocessing conditions, i.e.: formation of 3D crosslinked network in polyperoxide bulk; and its grafting with complete coating of polyolefin surface, -- is considered. The method provides an availability of uniformly placed peroxide groups of one type over the polyolefin surface activated, which may further be utilized for the tailored modification of polymer surfaces using the “grafting to” and “grafting from” techniques in that time when it is necessary. 相似文献
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Fridrikh Dyachkovskii 《先进技术聚合物》1993,4(7):423-428
Polyolefins are basic materials in the plastics. Their application is limited by their low thermostability, adhesion, hardness and other physico-mechanical properties. The following treatments are known to improve and modify polyolefin properties: the incorporation of inorganic or organic fillers with a greater hardness and rigidity into the polyolefin matrix, the grafting of functional groups to polyolefins, and crosslinking with the formation of a network structure in the polyolefin matrix. In the case of polymers and inorganic materials, the activation of their surface by the functionalizing and fixing of transition metals allows one to perform polymerization of monomers on a surface to obtain a polymer–polymer composites and a highly filled polymer–inorganic composites. 相似文献
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This paper presents an overview on recent developments in surface modification of polymer membranes for reduction of their fouling with biocolloids and organic colloids in pressure driven membrane processes. First, colloidal interactions such as London–van der Waals, electrical, hydration, hydrophobic, steric forces and membrane surface properties such as hydrophilicity, charge and surface roughness, which affect membrane fouling, have been discussed and the main goals of the membrane surface modification for fouling reduction have been outlined. Thereafter the recent studies on reduction of (bio)colloidal of polymer membranes using ultraviolet/redox initiated surface grafting, physical coating/adsorption of a protective layer on the membrane surface, chemical reactions or surface modification of polymer membranes with nanoparticles as well as using of advanced atomic force microscopy to characterize (bio)colloidal fouling have been critically summarized. 相似文献
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SURFACE MODIFICATION OF MICROPOROUS POLYPROPYLENE MEMBRANES BY GRAFT POLYMERIZATION OF N,N-DIMETHYLAMINOETHYL METHACRYLATE 总被引:2,自引:0,他引:2
Surface modification of microporous polypropylene hollow fiber membranes was performed by radical-induced graft polymerization of N,N-dimethylaminoethyl methacrylate (DMAEMA). The influences of temperature, monomer concentration and pre-adsorbed amount of benzoyl peroxide on grafting degree were studied respectively. It was found that the appropriate graft temperature was 75℃, at which the grafting degree was the highest and the hydrolytic decomposition of DMAEMA the lowest. Scanning electron photomicrography and the average pore diameters of the modified membranes demonstrated that part of the micropores on the membrane surface was plugged by the grafted polyDMAEMA chains, especially at high grafting degree. Contact angle and water swelling experiments showed that a moderate grafting degree could improve the hydrophilicity of the membranes. In the range of I 1.3%o-12.0% grafting degree, the water swelling percentage reached its maximum (51.1%) and the contact angle reached its minimum (74 degrees). The bovine serum albumin (BSA) adsorption experiment indicated that the grafted polyDMAEMA had a dual effect on protein adsorption. At the first stage, the BSA adsorption decreased with increasing of DMAEMA grafting degree. As the interaction between BSA and polyDMAEMA on membrane surface increased, the BSA adsorption increased with increasing of DMAEMA grafting degree. 相似文献
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聚丙烯和聚乙烯熔融接枝改性及增容 总被引:1,自引:0,他引:1
近年来,有关高分子改性研究已引起人们的广泛关注。本文对热塑性塑料聚丙烯和聚乙烯熔融接枝改性的常用单体、提高接枝率的方法、增容作用和接枝物的表征等方面进行了综述。 相似文献
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Silva SS Luna SM Gomes ME Benesch J Pashkuleva I Mano JF Reis RL 《Macromolecular bioscience》2008,8(6):568-576
Surface modification of biomaterials is a way to tailor cell responses whilst retaining the bulk properties. In this work, chitosan membranes were prepared by solvent casting and treated with nitrogen or argon plasma at 20 W for 10-40 min. AFM indicated an increase in the surface roughness as a result of the ongoing etching process. XPS and contact angle measurements showed different surface elemental compositions and higher surface free energy. The MTS test and direct contact assays with an L929 fibroblast cell line indicated that the plasma treatment improved the cell adhesion and proliferation. Overall, the results demonstrated that such plasma treatments could significantly improve the biocompatibility of chitosan membranes and thus improve their potential in wound dressings and tissue engineering applications. 相似文献
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Yoshito Ikada 《Macromolecular Symposia》1996,101(1):455-462
Surface modification of biomedical polymers by the technique of surface grafting was briefly overviewed, mostly based on our results. It was shown that surface grafting of water-soluble polymer chains onto polymeric biomaterials was effective in producing mechanically non-stimulative, blood-compatible, antibacterial, tissue-bonding, and cell-adhesive surfaces. In addition to the improvement of the interfacial biocompatibility, the surface grafting was useful also for obtaining a biofunctional surface such as immunoadsorbent. 相似文献