共查询到20条相似文献,搜索用时 15 毫秒
1.
Copolyamides were prepared from mixed diamine components of 3,3′‐ or 4,4′‐diaminodiphenylsulfone, piperazine, and dichlorides such as isophthaloyl or terephthaloyl. The obtained copolyamides are random copolymers, which have good solubilities in organic solvents and good mechanical properties, even in water. The asymmetric membranes prepared from the copolyamides [ex: 4I‐PIP(20)] not only have more excellent reverse osmosis performance, but also higher chlorine resistance than NOMEX‐type aromatic polyamide. New membrane materials with excellent reverse osmosis performance and higher chlorine resistance than the NOMEX‐type aromatic polyamide could be demonstrated successfully. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 1357–1364, 2000 相似文献
2.
中空纤维纳滤膜与反渗透膜的研究 总被引:1,自引:0,他引:1
根据界面聚合反应成膜原理,以哌嗪(PIP)或间苯二胺(m-PD)水溶液为水相,均苯三甲酰氯(TMC)正己烷溶液为有机相,以聚砜中空纤维超滤膜为基膜,制备了一系列聚酰胺/聚砜纳滤或反渗透复合膜.研究了水相浓度、有机相浓度、界面聚合时间和温度等条件对复合膜性能的影响.结果表明:中空纤维纳滤复合膜在0.4 MPa、室温条件下,对2 g/L MgSO_4水溶液的通量可达36.64 L/(m~2·h),截留率为97.2%;中空纤维反渗透膜在0.7 MPa、室温条件下,对0.5 g/L的NaCl水溶液通量可达12.2 L/(m~2·h),截留率96.5%. 相似文献
3.
Pei Sean Goh Kar Chun Wong Tuck Whye Wong Ahmad Fauzi Ismail 《Frontiers of Chemical Science and Engineering》2022,16(5):564
Polyamide thin film composite membranes have dominated current reverse osmosis market on account of their excellent separation performances compared to the integrally skinned counterparts. Despite their very promising separation performance, chlorine-induced degradation resulted from the susceptibility of polyamide toward chlorine attack has been regarded as the Achilles’s heel of polyamide thin film composite. The free chlorine species present during chlorine treatment can impair membrane performance through chlorination and depolymerization of the polyamide selective layer. From material point of view, a chemically stable membrane is crucial for the sustainable application of membrane separation process as it warrants a longer membrane lifespan and reduces the cost involved in membrane replacement. Various strategies, particularly those involved membrane material optimization and surface modifications, have been established to address this issue. This review discusses membrane degradation by free chlorine attack and its correlation with the surface chemistry of polyamide. The advancement in the development of chlorine resistant polyamide thin film composite membranes is reviewed based on the state-of-the-art surface modifications and tailoring approaches which include the in situ and post-fabrication membrane modifications using a broad range of functional materials. The challenges and future directions in this field are also highlighted. 相似文献
4.
5.
为改善分子筛Silicalite-1与聚酰胺(PA)之间的相容性,减少膜内非选择性的缺陷,采用双酚A型环氧树脂(BE188)对分子筛纳米颗粒表面进行改性,并将其添加到PA层中制备分子筛杂化膜。TEM表征结果证明:分子筛经表面改性后,不但提高了在PA基质中的分散性,而且与PA基质之间的相容性也明显改善,从而减少了界面缺陷。将所制备的膜用于2 g/L氯化钠水溶液反渗透脱盐,发现改性分子筛杂化膜的分离性能优于未改性分子筛杂化膜。且当改性分子筛的添加量为1 mg/mL时,膜的水通量为38.72 L/(m2.h),约为PA膜的1.5倍,同时膜的截留率也有所提高。 相似文献
6.
For the development of chlorine‐resistant nanofiltration membranes, a thin‐film‐composite membrane was prepared by the interfacial polymerization of N‐phenylethylenediamine and 1,3,5‐benzenetricarbonyl trichloride on a microporous polysulfone support substrate. The polymerization on the substrate surface was confirmed by Fourier transform infrared measurements, and membrane surface properties such as the roughness and ζ potential were characterized. Rejections of NaCl and isopropyl alcohol of the prepared membrane were 95 and 50%, respectively. The membrane showed much higher chlorine resistance than a commercial polyamide membrane when the membranes were immersed in an aqueous NaOCl solution. A field test was carried out with a spiral‐type membrane module. Tap water was treated by this module for more than 70 days under the condition of continuous NaOCl injection. The prepared membrane module was quite stable, and no distinguished change in the rejection and flux was recognized. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 相似文献
7.
The presently used hollow fiber membrane modules consist of a bundle of fibers in a cylindrical polymer or metal shell parallel to the shell axis. The feed solution flows either through the lumen or at the outside parallel to the fibers. This paper compares the performance of these modules with a new transverse flow module where the hollow fibers are positioned perpendicularly to the flow direction. For both types of modules the product costs are calculated for desalination by reverse osmosis and Dextran concentration by ultrafiltration. These calculations are based on literature data. The main conclusion is that the application of the tr‘ansverse flow module is only attractive if the permeation resistance is mainly determined by the hydrodynamics (ultrafiltration) and not attractive if the membrane permeability is the main resistance (reverse osmosis). 相似文献
8.
9.
10.
11.
The preparation of asymmetric flat membranes from a series of novel aromatic polyamides comprising 3,3′‐diaminodiphenylsulfone and a comonomer with a carboxyl group(&BOND;COOH) were studied and the measurements of reverse osmosis (RO) performance and chlorine resistance were carried out. It was confirmed that the introduction of comonomer with a carboxyl group (MC or Tm) to the aromatic polyamides (3I or 3T) comprising 3,3′‐diaminodiphenylsulfone was very effective for the improvement of its RO performance. In particular, 3T‐MC(30), which was prepared from terephthaloyl dichloride and mixed diamine components of 3,3′‐diaminodiphenylsulfone and 3,5‐diaminobenzoic acid, exhibited not only some potential for sea water desalination (FR = 159 L/m2 day, Rj = 98.3%) but also higher chlorine resistance than conventional Nomex‐type aramid [MI‐MC(0)]. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 505–513, 2001 相似文献
12.
Several analyses of hollow fiber reverse osmosis (RO) modules in which permeate water flows from the outer to the inner side of the membrane have been attempted over the past 20 years. In our previous work, an FCP (Friction Concentration Polarization) model showed good agreement with a wide range of actual performance data of a hollow fiber RO membrane module of radial flow type. In this work, this analytical model was applied to axial flow type hollow fiber modules. The performance of the axial flow type module with high packing density of hollow fibers was analyzed, taking into consideration the axial concentration profile in the module. It was confirmed that this model showed good agreement with experimental data for an axial flow type RO membrane module. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
13.
反渗透(RO)膜分离技术由于具有高效、低耗和产水水质高等优点,已成为现阶段解决水资源短缺的有效手段。进一步提高RO膜的选择透过性能有利于降低产水成本和提高产水质量,因此制备高选择透过性能的RO膜一直是膜领域研究的重点。从优化界面聚合工艺、优化基膜及开发新型制膜工艺三方面对近年来改善RO膜选择透过性能的研究进行了综述。通过优化界面聚合工艺和开发新型制膜工艺可以直接改变分离层的结构和性质,通过调节基膜的孔径、孔隙率及亲疏水性可以影响分离层的结构,从而改善RO膜的性能。最后对制备高选择透过性能的反渗透膜的研究方向与发展前景进行了总结与展望。 相似文献
14.
15.
16.
17.
Robust and high performance pressure retarded osmosis hollow fiber membranes for osmotic power generation
下载免费PDF全文
![点击此处可从《American Institute of Chemical Engineers》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Novel fabrication perspectives have been demonstrated to molecularly construct robust hollow fiber membrane supports for high performance thin‐film composite (TFC) pressure retarded osmosis (PRO) membranes. For the first time, we found that the desirable hollow fiber supports should possess high stretch resistance and acceptable ductility. The microstructure strength of the hollow fiber support may have more weights on overall robustness of the TFC PRO membranes than the apparent cross‐section morphology. Effectively manipulating the kinetics of phase inversion during spinning by maneuvering bore fluid chemistry, and polymer solution composition is a promising method to tailor the strength of hollow fiber supports. Prestabilization of the TFC membranes at elevated lumen pressures can significantly improve their PRO performance. The newly developed TFC PRO hollow fiber membranes exhibit a power density as high as 16.5 W/m2 and a very low specific reverse salt flux (Js/Jw) of 0.015 mol/L at a hydraulic pressure of 15 bar using synthetic seawater brine (1.0 M NaCl) as the draw solution. © 2014 American Institute of Chemical Engineers AIChE J, 60: 1107–1119, 2014 相似文献
18.
Na Zhang Tingting Yan Chunhui Li Huining Deng Zhenhua Li Ru Yu Tiejun Wang Shicai Xu Qiang Li Jihua Wang 《应用聚合物科学杂志》2021,138(32):50808
A series of polyamide thin-film nanocomposite (PA TFN) membranes have been fabricated by incorporating hydrophilic poly(dopamine) (PDA) coated carbon nanotubes (CNTs@PDA) into the PA selective layer via interfacial polymerization. The effects of PDA coating thickness on surface characteristics and separation performances of membranes are studied in detail. The PDA coating makes the surface of PA TFN membrane more hydrophilic, smoother and less electronegative. The desalination performance is obviously influenced by the coating thickness of PDA and the loading concentration of PDA@CNTs. The water fluxes of PDA@CNTs incorporated PA TFN membranes have been improved without sacrificing NaCl rejections. When the loading concentration is 0.0010%, the maximum water flux is 48.1 L m−2 h increasing by 45% compared with that of pristine PA membrane. Meanwhile, the NaCl rejection is up to 99.8%. The CNTs@PDA incorporated PA TFN membranes exhibit better anti-fouling property and separation performance durability. This work proves that CNTs@PDA has great potential application in PA TFN membranes. 相似文献
19.
20.
Jiawei Zhu Shaobin Guo Gongping Liu Zhengkun Liu Zhicheng Zhang Wanqin Jin 《American Institute of Chemical Engineers》2015,61(8):2592-2599
To accelerate the commercial application of mixed‐conducting membrane reactor for catalytic reaction processes, a robust mixed‐conducting multichannel hollow fiber (MCMHF) membrane reactor was constructed and characterized in this work. The MCMHF membrane based on reduction‐tolerant and CO2‐stable SrFe0.8Nb0.2O3‐δ (SFN) oxide not only possesses a good mechanical strength but also has a high oxygen permeation flux under air/He gradient, which is about four times that of SFN disk membrane. When partial oxidation of methane (POM) was performed in the MCMHF membrane reactor, excellent reaction performance (oxygen flux of 19.2 mL min?1 cm?2, hydrogen production rate of 54.7 mL min?1 cm?2, methane conversion of 94.6% and the CO selectivity of 99%) was achieved at 1173 K. And also, the MCMHF membrane reactor for POM reaction was operated stably for 120 h without obvious degradation of reaction performance. © 2015 American Institute of Chemical Engineers AIChE J, 61: 2592–2599, 2015 相似文献