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Takaomi Kobayashi Toshihiko Nagai Matsutaro Ono Nobuyuki Fujii 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1996,65(1):49-55
Continuous ultrafiltration of synthetic waste water containing peptone was carried out by using positively and negatively charged polyacrylonitrile membranes. The filtration experiments were operated in cross-flow mode under 10 kPa of applied pressure. The filtration properties of the charged membranes were compared with those of uncharged polyacrylonitrile ultrafiltration membranes having similar molecular sieve characteristics and membrane structure to the charged ultrafiltration membranes. During the continuous filtration, the filtration rate decreased and the operation pressure increased because of the formation of a peptone gel layer on the membrane surface. It was found that, for the positively charged membrane, the decrease in the filtration rate of the charged membranes was smaller than that of the uncharged membrane. In addition, the positively charged membrane maintained the initial operation pressure during the filtration. The reduction of fouling in the positively charged membrane was discussed by analyzing the gel components on the membrane surface. 相似文献
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Ultrafiltration membrane based on polyacrylonitrile prepared by phase inversion method using zinc chloride as an additive showed more than 90% rejection for BSA and 90–110 lm?2 h?1 water flux. The surface modification of this membrane was studied using ethanolamine, triethylamine, sodium hydroxide, and potassium hydroxide solutions. The effect of base treatment time and temperature on water flux and rejection was investigated. The membranes exhibited swelling by NaOH treatment followed by deswelling by HCl post‐treatment, similar to pH responsive membranes. The treatment by organic as well as inorganic bases improved water flux with a slight lowering in BSA rejection by dead‐end mode type treatment. A 230% increase in water flux was achieved by sodium hydroxide treatment in crossflow mode without a noticeable pore swelling by SEM. The contact angle of the modified membranes was decreased as compared to the unmodified one indicating appreciable surface modification. As the treatment time or temperature increased, the ESCA analysis showed increased population of Na‐carboxylate groups. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4378–4385, 2006 相似文献
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Conventional hydrolysis modification of polyacrylonitrile (PAN) membranes is usually carried out in a post-treatment step during which hydrophilic groups are created on the membrane surface. In this article, however, direct hydrolysis in the immersion bath is proposed as a new and simple approach for simultaneous membrane preparation and modification. The main advantages of this method include lower alkali concentrations, promptness, and the lack of need for elevating temperature compared to other studies. The cast films were immersed in the coagulation bath containing aqueous NaOH solutions of various concentrations (0.003, 0.0125, 0.025, 0.05, and 0.1 M) for 1, 3, 5, and 10 min, which were then transferred to a bath of pure water. Membranes were characterized by pure water flux, porosity, average pore diameter, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle, mechanical properties, rejection, and flux recovery ratio (FRR) measurements. At all treatment times, the pure water flux of modified membranes reached its maximum at low NaOH concentrations with a substantial increase (210%) in the membrane treated with 0.0125 M NaOH for 1 min. Furthermore, the kinetics of the hydrolysis reaction was considered to provide deeper insights into morphological changes occurring during the hydrolysis. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48583. 相似文献
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Supported ultrafiltration (UF) membranes based on polyacrylonitrile were prepared by phase inversion method using nonwoven polyester fabric as support with different origin. The membrane preparation parameters, including dope solution composition and casting conditions, were kept same while changing the support fabric. Various analyses performed, viz. water flux, protein rejection, porosity, and membrane compaction indicated that the support used for UF membrane preparation affects the membrane properties to a great extent, and a right support need to be chosen for a preparation of membrane with desired properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99:3389–3395, 2006 相似文献
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利用二次生长法,以十六烷基三甲基溴化铵(CTAB)为结构导向剂,一步水热合成了多级孔道ZSM-5分子筛膜。结果表明,CTAB球形胶束与分子筛颗粒自组装形成了介孔结构,同时,CTAB胶束及疏水长链抑制了晶体的长大。通过调整CTAB/SiO2摩尔比、合成温度及晶化时间等制膜条件,改变分子筛膜的晶体颗粒尺寸及膜层交联度,实现了分子筛膜介孔结构的有效调节,其孔径范围7~30 nm。在CTAB/SiO2摩尔比为0.05、合成温度180℃、时间20 h下,多级孔分子筛膜纯水渗透通量达到138 kg·m-2·h-1·MPa-1,截留分子量28500,对应平均孔径7.39 nm,达到小孔径超滤的标准。 相似文献
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M. A. M. Beerlage J. M. M. Peeters J. A. M. Nolten M. H. V. Mulder H. Strathmann 《应用聚合物科学杂志》2000,75(9):1180-1193
The hindered diffusion of polystyrene in dilute solutions of ethyl acetate through polyimide ultrafiltration membranes has been investigated. The present system did not show specific membrane‐solute interactions; furthermore, polystyrene can be considered as a flexible polymer coil. It is shown that the hindered diffusive permeability for monodisperse dilute solutions for a series of molecular weights can be compared well with the diffusive permeability curve of one polydisperse dilute polystyrene solution. In the case of very dilute solutions, the polymer coils have no interaction with each other, and the whole range of molecular‐weight‐dependent permeabilities can be determined from only one measurement. The diffusion behavior of polydisperse solutions through various polyimide membranes has been investigated as well. It was found that the diffusive permeability curve is strongly dependent on the type of membrane, that is, on the pore size distribution. It was not possible to calculate a pore size distribution from diffusion experiments due to mathematical limitations. Nevertheless, it was shown that hindered diffusion measurements are useful to estimate a maximum pore size for each membrane. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 1180–1193, 2000 相似文献
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The novel positively charged poly(ether ether ketone)s (PEEKs) with pendant quaternary ammonium groups were synthesized by copolymerization of 3, 3′‐dimethylaminemethylene‐4,4′‐biphenol (DABP), 3,3′,4,4′‐tetramethylbiphenol, and 4,4′‐bisfluorobenzophenone followed by reaction with iodomethane. The resulting copolymers were used to prepare thin film composite (TFC) nanofiltration (NF) membranes via the dip‐coating method. The effects of different parameters such as copolymer concentration and curing time on the membrane performance (flux and rejection of inorganic salts) were investigated. The optimum parameters were that 1.5 wt % quaternary ammonium PEEK containing 1.8 quaternary ammonium groups per unit with 0.5 wt % DMSO coated on the polysulfone (PSf) support membrane and cured at 100°C. The results of the performance testing showed that the trend for rejection was R > R > RNaCl > R (R = rejection), which was a typical positively charged membrane. The best performance of these composite nanofiltration membranes was 91.3% rejection for 500 ppm MgCl2 and 62.5 L/m2 h water permeability at 0.4 MPa. The MWCO of the membrane was 800 Da. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
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Hong Ying Wang Takaomi Kobayashi Nobuyuki Fujii 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1997,70(4):355-362
A cross-linking polymeric layer containing molecular imprint sites of theophylline (THO) was formed on a polyacrylonitrile membrane, which had a photosensitive dithiocarbamate group, by photograft copolymerization. In the presence of THO template molecules, aqueous solutions of N, N′-methylenebisacrylamide (MBAA) and acrylic acid (AA) were used for the photo-initiated polymerization. After the photograft polymerization, removal of the template was carried out and then an aqueous solution of THO or caffeine (CAF) was permeated through the resultant membrane. It was found that the polymeric layer of MBAA and AA formed on the membrane surface can recognize with high efficiency the THO molecule and take it up into the surface layer of the membrane. Relative to THO, CAF was not taken up effectively by the membrane. The results indicated that the photograft treatment is useful for the formation of the THO-imprinted polymeric layer on the membrane surface. ©1997 SCI 相似文献
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紫外辐照接枝制备荷正电纳滤膜 总被引:1,自引:0,他引:1
通过在PEK-C微孔膜表面紫外辐照接枝甲基丙烯酰氧乙基三甲基氯化铵(DMC)制备了一种表面荷正电的纳滤膜。通过测定膜的纯水通量和对不同盐溶液截留率的变化,系统研究了接枝条件对膜分离性能的影响。结果表明,采用该方法制成的纳滤膜对高价阳离子盐溶液MgCl2的截留率和渗透通量都较高。 相似文献
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Cecilia Pagliero Nelio Ochoa Jos Marchese Miguel Mattea 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2004,79(2):148-152
The removal of phospholipids (‘degumming’) is the first step in the process of refining crude vegetable oil. Membrane separation has been often proposed as an alternative to the conventional procedure (water degumming). Until now, the instability of polymeric membranes in organic solvents has been the major obstacle in applying this technique. In this work, a local synthesized polyvinylidenefluoride (PVDF) and a commercial polyimide (PI) membrane were evaluated for their flux and rejection properties during degumming of soybean oil in a laboratory‐scale cross‐flow ultrafiltration cell. Degumming experiments were done at different temperatures and feed flows, keeping constant both the feed concentration and the transmembrane pressure. PVDF and PI membranes gave selectivity values and permeate color that did not differ significantly from each other. Retention coefficients larger than 98% were obtained in all cases. In every experiment, a decline in permeate flux with time occurred at the beginning of the degumming process. By increasing the feed rate, a higher permeate flux was obtained. The results show that the PVDF membrane had a higher productivity than the PI one. Copyright © 2003 Society of Chemical Industry 相似文献
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采用紫外光法将马来酸酐(MAH)单体键联到聚丙烯腈(PAN)超滤膜表面,考察了紫外光强度、辐射时间、光敏剂浓度以及单体浓度对MAH反应率的影响。采用衰减全反射-傅里叶红外光谱(ATR /FT-IR)、扫描电镜(SEM)和水接触角(CA)对改性膜和原膜进行表征,结果表明单体MAH已成功键联到PAN膜表面,膜表面的亲水性得到提高。蛋白质静态污染以及超滤实验表明马来酸酐键联改性对PAN膜水通量影响不大,但抗污染性能得到明显提高,且由于MAH含有酸酐基团,使PAN膜的可反应性大大提高,使PAN膜易于进一步改性。 相似文献
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Zhenghui Liu Jun Xiang Xiaoli Hu Penggao Cheng Lei Zhang Wei Du Songbo Wang Na Tang 《中国化学工程学报》2021,34(6):332-340
Polyphenylsulfone(PPSU)ultrafiltration membrane with different structures was prepared by non-solvent-induced phase separation.The effects of coagulation bath conditions(concentration and temper-ature)on membrane morphology,pure water flux,pore size,porosity,and contact angle were studied and discussed based on ternary-phase diagrams.Results indicated that water had stronger coagulant power than ethanol,and that the morphology of the membrane prepared from the polyphenylsulfone/1-methyl-2-pyrrolidinone/H2O(PPSU/NMP/H2O)system had finger-like structures.Conversely,sponge-like struc-tures were observed for the PPSU/NMP/(NMP-H2O)and PPSU/NMP/(70NMP-EtOH-H2O)systems.Ethanol also greatly influenced on membrane structures.According to the Scanning electronic micro-scopy(SEM)image,the composition(mass fraction)of casting solution is 16%PPSU-84%NMP and the coagulation bath consisting of 70%NMP-26%H2O-4%C2H5OH.Meanwhile,the PPSU ultrafiltration mem-brane with spong-like was prepared under 8℃coagulation bath.The formation of sponge-like structure reduces the pure water flux of ppsu membrane from 488.39 L·m-2·h-1 to 36.04 L m-2·h-1.It also reduces the gas permeability,porosity,and pore size of the membrane.The addition of ethanol and NMP into the coagulation bath increases the roughness of the PPSU ultrafiltration membrane and reduces the hydrophilicity of the membrane. 相似文献
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A study was done of the ultrafiltration properties of expanded polytetrafluoroethylene (ePTFE) films with two average pore sizes, 0.5 and 3.0 μm, grafted with 2‐(dimethylamino)ethyl methacrylate (DMAEMA)—grafted 0.5‐ePTFE and grafted 3.0‐ePTFE—using dextran (Dxt) and quaternized dextran (qDxt) in water and in buffer solutions with a pH in the range of 4–10. The water permeability was found to be proportional to the operating pressure below 2.0 kgf/cm2. Grafted 0.5‐ePTFE films apparently had a higher rejection than did the grafted 3.0‐ePTFE films, and the cutoff value for grafted 0.5‐ePTFE films decreased with an increase in the grafted amount. The apparent rejection of Dxt and qDxt increased with a decrease in the pH value, and the apparent rejection of qDxt was higher than that of Dxt when the pH was in the range of 4–8 because of an electrostatically repulsive interaction between positively charged grafted PDMAEMA chains and qDxt molecules. For grafted 0.5‐ePTFE films, 40KDxt was selectively separated from the 40KDxt/250KDxt mixture systems in water and from the 40KDxt/40KqDxt mixture systems at pH 6 using the difference in their apparent rejection; the separation factors in both systems increased with the grafted amount. These results indicate that grafted ePTFE films are applicable to positively charged ultrafiltration membranes. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1595–1604, 2001 相似文献
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Comparison of antimicrobial activities of polyacrylonitrile fibers modified with quaternary phosphonium salts having different alkyl chain lengths 下载免费PDF全文
A series of polyacrylonitrile fibers (PANF) modified with quaternary phosphonium salts having various alkyl chain lengths (C1, C2, C6, C8, C12) were synthesized and compared for their antimicrobial activities by the improved shake flask method. The as‐prepared fibers were named MTPB‐PANF, ETPB‐PANF, HTPB‐PANF, OTPB‐PANF, and DTPB‐PANF, respectively. The representative microorganisms employed were Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), Pseudomonas aeruginosa (P. aeruginosa), and Candida albicans (C. albicans). Results from the current study showed that the alkyl chain length of quaternary phosphonium salts not only affected the synthesis of the fibers, but also impacted their antimicrobial activities. There was a rule that the longer the alkyl chain length, the more easily the quaternary phosphonium salts modify the fibers and the better the antimicrobial activities of the modified fibers. All the modified fibers exhibited good broad‐spectrum antimicrobial activities. Specifically, DTPB‐PANF exhibited an outstandingly high antimicrobial activity, which was nearly unaffected by the environmental pH (3–10). It can kill all the four pathogens in 15 min and had an excellent wash‐resistant property. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43689. 相似文献
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C. S. Latha D. Shanthanalakshmi D. Mohan K. Balu M. D. K. Kumarasamy 《应用聚合物科学杂志》2005,97(3):1307-1315
Polysulfone was functionalized by carboxylation and blended with polyurethane (ether type). Blend membranes were prepared in the presence and absence of the additive poly(ethylene glycol) 600 and subjected to ultrafiltration characterizations such as compaction, pure water flux, water content, and hydraulic resistance. Morphological studies of the membranes were performed with scanning electron microscopy. The effects of the polymer composition and additive concentrations on the above parameters were analyzed and the results compared. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1307–1315, 2005 相似文献