The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Congjie Gao - One of the best experts on this subject based on the ideXlab platform.
-
high flux and fouling resistant reverse osmosis membrane prepared with incorporating zwitterionic amine monomers via Interfacial Polymerization
Desalination, 2016Co-Authors: Xiaodan Weng, Congjie GaoAbstract:Abstract Zwitterionic monomers have aroused great attraction for membrane preparation due to their tremendous hydrophilicity and antifouling properties. Zwitterionic diamine monomer N-aminoethyl piperazine propane sulfonate (AEPPS) was added into m-phenylenediamine (MPD) aqueous solution to react with trimesoyl chloride (TMC) via Interfacial Polymerization to fabricate zwitterionic thin film composite reverse osmosis membrane (TFCMZs). The membrane preparation conditions, including AEPPS content, TMC concentration and curing temperature, were systematically evaluated. The membrane surface hydrophilicity and antifouling properties of TFCMZs were greatly enhanced via introducing AEPPS into membranes. When tested with brackish water desalination conditions (2000 ppm NaCl feed solution at 1.5 MPa and 25 °C), the water flux of TFCMZs containing 10% AEPPS was significantly increased to be 54.5 ± 3.2 L·m− 2·h− 1, which is about an 82% increase compared with the pristine membrane, while the NaCl rejection remains above 98%. Furthermore, using tannic acid (TA) and sodium alginate (NaAlg) as model foulants, the TFCMZs displayed outstanding fouling-resistant and easy-cleaning properties. TFCMZs present both admirable separation and fouling-resistance performance, which indicates that TFCMZs have wide application potential for brackish water desalination.
-
study on a novel nanofiltration membrane prepared by Interfacial Polymerization with zwitterionic amine monomers
Journal of Membrane Science, 2013Co-Authors: Quanfu A, Qiang Zhao, Congjie GaoAbstract:Abstract A novel zwitterionic amide monomer (N-aminoethyl piperazine propane sulfonate, AEPPS) was synthesized and utilized in conjunction with piperazine (PIP) to perform the Interfacial Polymerization with trimesoyl chloride (TMC), producing thin-film composite (TFC) nanofiltration membranes (NFMs) with improved separation performance and antifouling property. Chemical structures and compositions of the zwitterionic monomers AEPPS and NFMs were characterized by (attenuated total reflectance) fourier transform infrared spectroscopy, nuclear magnetic resonance spectrometer and X-ray photoelectron spectroscopy. The surface morphology and hydrophilicity of NFMs were examined by field emission scanning electron microscopy, atomic force microscopy, dynamic water contact angle. The water permeability and antifouling property of NFMs are improved via introducing AEPPS into membranes. When tested with 1 g L −1 K 2 SO 4 aqueous solution at 25 °C and 0.6 MPa, the water flux of NFMs increases from 23.4 L m −2 h −1 to 43.1 L m −2 h −1 with increasing AEPPS content from 0 mol% to 3.2 mol%, while K 2 SO 4 rejection maintains around 97%. The NFMs containing zwitterionic moieties can resist bacterial adsorption and protein fouling efficiently, and show a stable and good separation performance during a long-time filtration process of 288 h.
-
preparation of monodispersed spherical mesoporous nanosilica polyamide thin film composite reverse osmosis membranes via Interfacial Polymerization
Desalination, 2013Co-Authors: Mengru Bao, Guiru Zhu, Li Wang, Meng Wang, Congjie GaoAbstract:Abstract Monodispersed spherical mesoporous nanosilicas were synthesized by the hydrothermal method using tetraethoxysilane as silica source, cetyltrimethylammonium bromide as template, ethanol as co-solvent, and sodium hydroxide as alkali source. The synthesized silica has an average particle diameter of 164 nm with a relative standard deviation of 4.87%, specific surface area of 1141 m 2 ·g − 1 , pore size of 2.47 nm, pore volume of 0.77 cm 3 ·g − 1 , and a pore structure radiating from the heart to the outer surface of the sphere. The spherical mesoporous nanosilica–polyamide thin film composite reverse osmosis (TFC RO) membranes were obtained by Interfacial Polymerization. The silica nanoparticles are visible in the TFC RO membranes based on the surface and cross-sectional SEM images. Correspondingly, energy dispersive X-ray spectroscopy analysis confirms that the silica has been successfully doped into the TFC RO membranes. The hydrophilicity of the TFC RO membranes is improved and water flux is increased from 19 L·h − 1 ·m − 2 (without nanosilica) to 53 L·h − 1 ·m − 2 (with 0.1% (w/v) mesoporous nanosilica loading), whereas all solute rejection rates are greater than 96%.
-
thin film composite membrane formed by Interfacial Polymerization of polyvinylamine pvam and trimesoyl chloride tmc for nanofiltration
Desalination, 2012Co-Authors: Meihong Liu, Yinping Zheng, Shi Shuai, Qing Zhou, Congjie GaoAbstract:Abstract This study focus on the preparation and nanofiltration properties of a novel thin-film composite polyamide membrane formed by the Interfacial Polymerization of polyvinylamine (PVAm) and trimesoyl chloride (TMC) on a porous polysulfone supporting membrane. The fabrication of the PVAm–TMC composite membrane was conducted by studying preparation parameters including reaction time, pH of the aqueous phase solution, reactant concentration, as well as curing temperature and time. The properties of the resultant membrane were characterized in terms of morphological structure, surface zeta potential, pure water flux, molecular weight cut-off (MWCO) and rejections to different solutes including electrolytes and organic dyes. The results showed that the optimized composite membrane had a smooth and amphoteric surface with an isoelectric point at pH about 6.5, a MWCO of around 650 Da, a pure water permeability of about 8.5 l/m2 h bar and good long-term stability. The rejection order of the membrane to inorganic salts changed from MgCl2
Suobo Zhang - One of the best experts on this subject based on the ideXlab platform.
-
positively charged nanofiltration membrane formed by Interfacial Polymerization of 3 3 5 5 biphenyl tetraacyl chloride and piperazine on a poly acrylonitrile pan support
Journal of Membrane Science, 2011Co-Authors: Haifeng Wang, Qifeng Zhang, Suobo ZhangAbstract:A novel TFC NF membrane was prepared on a polyacrylonitrile (PAN) supporting film using Interfacial Polymerization with the 3,3',5,5'-biphenyl tetraacyl chloride (mm-BTEC) monomer and piperazine (PIP). In the Interfacial Polymerization process, organic solvents were changed from cyclohexane to toluene, which increased the diffusion rate and solubility of PIP in the organic solvent. The diffusion of PIP and its solubility both influence the structure, morphology and thickness of TFC membranes. The streaming potential of TFC NF membranes was measured at various pHs. The results demonstrate that the surface of the membrane is positive charged. Permeation experiments were employed to evaluate the salt rejection and water flux performance of the membranes. These new NF films exhibited interesting performance properties as compared with commercial nanofiltration membranes in terms of their retention and relative flux for positively charged inorganic compounds. The salt rejection of the mm-BTEC/PIP membranes corresponding to different types of feed solutions are CaCl(2) > MgCl(2) > NaCl > Na(2)SO(4). The flux and rejection of CaCl(2) (500 ppm) were 50.8 L/m(2) h and 95.1%, respectively, under 0.4 Mpa. In addition, the NF membranes exhibited enhanced water permeability and salt rejection compared with those prepared from trimesoyl chloride (TMC). (C) 2011 Elsevier B.V. All rights reserved.
-
formation and structural evolution of biphenyl polyamide thin film on hollow fiber membrane during Interfacial Polymerization
Journal of Membrane Science, 2011Co-Authors: Benqiao He, Jianxin Li, Lei Li, R D Sanderson, Suobo ZhangAbstract:A novel reverse osmosis hollow fiber membrane was prepared by Interfacial Polymerization from 3,3′,5,5′-biphenyl tetraacyl chloride and m-phenylenediamine on a polysulfone hollow fiber membrane. The structural evolution of biphenyl polyamide thin film during Interfacial Polymerization was monitored by attenuated total reflectance infrared, X-ray photoelectron spectroscopy and atom force microscopy. The relationship between the structure and separation properties of the membranes was investigated. Results show that the biphenyl polyamide thin film had a three-layer structure: a loose initial layer with a low cross-linked structure, a dense middle layer with a high cross-linked structure and a loose surface layer with a low cross-linked structure. The dense middle layer had an intrinsic cross-linked structure with over 86.0% amide bonds (–CONH–) and below 14.0% carboxylic groups (–COOH), mainly responsible for separation. A growth model of the biphenyl polyamide thin film was proposed to describe the structural evolution process during Interfacial Polymerization.
-
preparation and characterization of poly piperazineamide composite nanofiltration membrane by Interfacial Polymerization of 3 3 5 5 biphenyl tetraacyl chloride and piperazine
Journal of Membrane Science, 2009Co-Authors: Lei Li, Suobo Zhang, Xiaosa ZhangAbstract:Abstract Most nanofiltration (NF) membranes are composite and have a polyamide thin film prepared by Interfacial Polymerization. Their performances mainly correlate the structure of the thin film and monomers used for its preparation. In this work, a novel thin-film composite (TFC) nanofiltration membrane was successfully prepared from 3,3′,5,5′-biphenyl tetraacyl chloride (mm-BTEC) and piperazine (PIP) through Interfacial Polymerization. Attenuated reflectance infrared (ATR-IR) and X-ray photoelectronic spectroscopy (XPS) were used to characterize the chemical composition of the membrane surface. The membrane performance was optimized by studying preparation parameters including monomer concentration, reaction time, and pH of aqueous phase. The resulting NF membrane exhibited significantly enhanced water permeability while maintaining high rejection to salt. The flux and rejection of NF membrane to Na2SO4 (500 ppm) reached to 51.5 L/(m2 h) and 95% under 0.5 MPa. The streaming potential tests indicated that the TFC membrane surface had high charge density and very low isoelectric point which situated between pH 1 and 2.
Zhongyi Jiang - One of the best experts on this subject based on the ideXlab platform.
-
covalent organic framework modulated Interfacial Polymerization for ultrathin desalination membranes
Journal of Materials Chemistry, 2019Co-Authors: Jinqiu Yuan, Runnan Zhang, Yanan Liu, Xinda You, Hao Yang, Jianliang Shen, Zhongyi JiangAbstract:The demand for thin-film composite nanofiltration membranes bearing unprecedented water permeance and desirable salt rejection is ever increasing in desalination. Conventional Interfacial Polymerization usually generates a thick (∼100 nm) skin layer on hydrophobic substrate having low-porosity, leading to limited water permeance. Herein, we engineered a highly porous and superhydrophilic composite substrate to modulate the Interfacial Polymerization and generate an ultrathin polyamide skin layer, even below 10 nm. The composite substrate was constructed by depositing covalent organic framework nanosheets (CONs) on a microfiltration membrane via vacuum-assistant assembly. Owing to the highly porous structure and superhydrophilic nature of CONs, the composite substrate favored a high storage capacity and uniform distribution of the amine monomers. We manipulated the monomer storage capacity of the substrate by varying the loading content of CONs and demonstrated that higher amino monomer concentration could accelerate the self-sealing and self-termination of the Interfacial Polymerization, thus generating a thinner skin layer from ∼70 nm to sub-10 nm. Moreover, the highly porous structure of CONs imparted little additional water transport resistance. The sub-10 nm film composite membrane exhibited a superior water permeance of 535.5 L m−2 h−1 MPa−1 with a high rejection of 94.3% for Na2SO4, which was about 2–8 times higher than that of state-of-the-art nanofiltration membranes with comparable rejection.
-
improved performance of composite nanofiltration membranes by adding calcium chloride in aqueous phase during Interfacial Polymerization process
Journal of Membrane Science, 2014Co-Authors: Xiaochen Fan, Yanan Dong, Xueting Zhao, Jiazhen Liu, Zhongyi JiangAbstract:Abstracts The composite nanofiltration membranes were prepared via Interfacial Polymerization of tetraethylenepentamine (TEPA) and 1,3,5-benzenetricarbonyl trichloride (TMC). The improved performance of the composite nanofiltratiom membranes by adding calcium chloride in aqueous phase during the Interfacial Polymerization was verified in terms of pure water permeability, rejection of different solutes including dyes and inorganic salts and chlorine resistance. The results showed that the pure water permeability of composite nanofiltration membranes would acquire a remarkable increase with a slight decrease in solute rejections under the optimized addition of CaCl 2 . The addition of CaCl 2 also dramatically enhanced the chloride resistance of composite nanofiltration membranes in comparison with the control membranes prepared without CaCl 2 added. Therefore, inorganic salts like CaCl 2 could be considered as a potential additive to enhance the performance of composite nanofiltration membranes.
-
separation performance of thin film composite nanofiltration membrane through Interfacial Polymerization using different amine monomers
Desalination, 2014Co-Authors: Yafei Li, Yanlei Su, Yanan Dong, Runnan Zhang, Xueting Zhao, Zhongyi Jiang, Jiaojiao ZhaoAbstract:Abstract Four kinds of thin-film composite (TFC) membranes were prepared via Interfacial Polymerization using diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA) and piperazidine (PIP) as water-soluble monomer, and trimesoyl chloride (TMC) as organic-soluble monomer. The surface chemical features of the resultant membranes were confirmed by contact angle measurement and Fourier transform infrared spectroscopy (FTIR). The membrane morphology and surface charges were investigated through Scanning electronic microscopy (SEM) and Zeta potential, respectively. Salt rejection was used to evaluate the separation performance of the four kinds of TFC membranes. The results showed that all the four kinds of TFC membranes exhibited typical negatively charged nanofiltration membrane characteristics. The salt rejections followed the sequence: Na2SO4 > MgSO4 > MgCl2 and the rejection of Na2SO4 was all over 80%. It was also found that the solubility of water-soluble monomer in organic solvent played an important role in manipulating the membrane structure, charge properties and thus the separation performance.
-
composite nanofiltration membranes prepared by Interfacial Polymerization with natural material tannic acid and trimesoyl chloride
Journal of Membrane Science, 2013Co-Authors: Ya Zhang, Jinming Peng, Jiazha Liu, Jiaojiao Zhao, Xueting Zhao, Zhongyi JiangAbstract:Abstract Natural material tannic acid was first selected as polyphenol monomer to fabricate the novel composite nanofitration membranes. There was chemical cross-linking reaction took place between the phenol groups of tannic acid and acyl chloride groups of trimesoyl chloride (TMC) in the water/oil Interfacial zone. The polyester thin layers from tannic acid and TMC Interfacial Polymerization on porous ultrafiltration membrane support were characterized by scanning electron microscope (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and water contact angle measurement. The effects of post treatment temperature and reaction time, and monomer concentrations in aqueous and organic solutions on water permeability, and rejection of dyes and inorganic salts of the nanofiltration membranes were studied, respectively. Tannic acid and TMC composite nanofiltration membranes had low flux decline ratios and high flux recovery ratios without chemical cleaning in the antifouling evaluation experiments. The excellent antifouling properties and chemical stability of tannic acid and TMC composite nanofiltration membranes made them have potential uses in wastewater treatment.
-
polyamide nanofiltration membrane with high separation performance prepared by edc nhs mediated Interfacial Polymerization
Journal of Membrane Science, 2013Co-Authors: Jinming Peng, Yanlei Su, Yanan Dong, Xueting Zhao, Zhongyi Jiang, Wenjuan Chen, Yan Zhang, Cao XingzhongAbstract:Composite nanofiltration membranes comprising polyamide active layer and polyacrylonitrile (PAN) support were prepared by 1-ethyl-(3-3-dimethylaminopropyl) carbodiimide hydrochloride (EDC)/N-hydroxysuccinimide (NHS) mediated Interfacial Polymerization. PAN support was first hydrolyzed to create carboxyl groups on surface, which were then activated by EDC/NHS to enhance reactivity with amine groups. Afterwards, activated PAN support was impregnated in aqueous phase containing piperazine (PIP). Finally, PIP impregnated PAN support was immersed in organic phase containing trimesoyl chloride (TMC), where the polyamide active layer was formed on the hydrolyzed PAN support. Fourier Transform Infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS) analysis verified the formation of amide bonds between PIP molecules and carboxyl groups on the hydrolyzed PAN support. Variation energy positron annihilation spectroscopy (VEPAS) measurement manifested that the active layer and Interfacial zone of composite membrane became denser owing to EDC/NHS activation. The water flux slightly decreased but the rejection of Orange GII remarkably increased with an increase in EDC concentration. The composite membrane prepared at EDC concentration 100 mM and PIP concentration 0.20 wt% exhibited a flux of MgSO4 solution as high as 511 L/(m(2) h MPa) while the rejection reached 98.5%. The structural stability of the composite membranes after EDC/NHS treatment was greatly enhanced as tested by alcohol treatment. (C) 2012 Elsevier B.V. All rights reserved.
Lei Li - One of the best experts on this subject based on the ideXlab platform.
-
formation and structural evolution of biphenyl polyamide thin film on hollow fiber membrane during Interfacial Polymerization
Journal of Membrane Science, 2011Co-Authors: Benqiao He, Jianxin Li, Lei Li, R D Sanderson, Suobo ZhangAbstract:A novel reverse osmosis hollow fiber membrane was prepared by Interfacial Polymerization from 3,3′,5,5′-biphenyl tetraacyl chloride and m-phenylenediamine on a polysulfone hollow fiber membrane. The structural evolution of biphenyl polyamide thin film during Interfacial Polymerization was monitored by attenuated total reflectance infrared, X-ray photoelectron spectroscopy and atom force microscopy. The relationship between the structure and separation properties of the membranes was investigated. Results show that the biphenyl polyamide thin film had a three-layer structure: a loose initial layer with a low cross-linked structure, a dense middle layer with a high cross-linked structure and a loose surface layer with a low cross-linked structure. The dense middle layer had an intrinsic cross-linked structure with over 86.0% amide bonds (–CONH–) and below 14.0% carboxylic groups (–COOH), mainly responsible for separation. A growth model of the biphenyl polyamide thin film was proposed to describe the structural evolution process during Interfacial Polymerization.
-
preparation and characterization of poly piperazineamide composite nanofiltration membrane by Interfacial Polymerization of 3 3 5 5 biphenyl tetraacyl chloride and piperazine
Journal of Membrane Science, 2009Co-Authors: Lei Li, Suobo Zhang, Xiaosa ZhangAbstract:Abstract Most nanofiltration (NF) membranes are composite and have a polyamide thin film prepared by Interfacial Polymerization. Their performances mainly correlate the structure of the thin film and monomers used for its preparation. In this work, a novel thin-film composite (TFC) nanofiltration membrane was successfully prepared from 3,3′,5,5′-biphenyl tetraacyl chloride (mm-BTEC) and piperazine (PIP) through Interfacial Polymerization. Attenuated reflectance infrared (ATR-IR) and X-ray photoelectronic spectroscopy (XPS) were used to characterize the chemical composition of the membrane surface. The membrane performance was optimized by studying preparation parameters including monomer concentration, reaction time, and pH of aqueous phase. The resulting NF membrane exhibited significantly enhanced water permeability while maintaining high rejection to salt. The flux and rejection of NF membrane to Na2SO4 (500 ppm) reached to 51.5 L/(m2 h) and 95% under 0.5 MPa. The streaming potential tests indicated that the TFC membrane surface had high charge density and very low isoelectric point which situated between pH 1 and 2.
Benjamin Chu - One of the best experts on this subject based on the ideXlab platform.
-
nanofiltration membranes prepared by Interfacial Polymerization on thin film nanofibrous composite scaffold
Polymer, 2014Co-Authors: Xiao Wang, Tsungming Yeh, Zhe Wang, Rui Yang, Ran Wang, Benjamin S Hsiao, Benjamin ChuAbstract:Abstract Nanofiltration (NF) membranes, consisting of a composite barrier layer prepared by Interfacial Polymerization of polyamide around the ultra-fine cellulose nanofibers (CN) layer in a thin-film nanofibrous composite (TFNC) scaffold, were demonstrated. Two Interfacial Polymerization pathways (termed IP and IP-R), regarding the arrangement of the aqueous and organic phases, were investigated. It was found that Interfacial Polymerization with the aqueous phase above the organic phase (IP-R) yielded better filtration performance, i.e., IP-R based membranes exhibited a higher MgCl2 rejection than IP based membranes. Transmission electron microscopy (TEM) observation indicated that the denser part of the barrier layer was on the CN layer surface of IP-R based membranes, whereas this portion was deeply immersed in the CN layer of IP based membranes. To investigate the structure and property relationship of the composite barrier layer, both IP and IP-R based membranes were treated with 1% trimesoyl chloride (TMC) in hexane. After treatment, the rejection of NaCl was found to increase from 74% to 91% for IP-R based membranes, while remained unchanged (∼75%) for IP based membranes. This behavior can be explained by the decrease in pore size due to the cross-linking of TMC and secondary amino groups in the barrier layer of IP-R based membranes, while the permeability in IP based membranes was probably mainly controlled by the water passage through channels formed at the interface between CN and polymer matrix in the barrier layer of IP based membranes, which is not dependent of the cross-linking reaction.
-
fabrication of thin film nanofibrous composite membranes by Interfacial Polymerization using ionic liquids as additives
Journal of Membrane Science, 2010Co-Authors: Lewis Yung, Xiao Wang, Ran Wang, Benjamin S Hsiao, Kyunghwan Yoon, Benjamin ChuAbstract:Abstract A new type of thin-film nanofibrous composite membrane (TFNC) for nanofiltration (NF), prepared by Interfacial Polymerization (IP) of piperazine (PIP) using ionic liquids (IL) was demonstrated. A comparison was first made to illustrate the advantage of using highly porous electrospun PES nanofibrous scaffold versus typical ultrafiltration (UF) membrane as the support for the PIP-based polyamide barrier layer. Two different ILs: 1-octyl-3-methylimidazolium chloride (OMIC) and 1-butyl-3-methyl-imidazolium chloride (BMIC), were incorporated in Interfacial Polymerization to adjust the permeation flux and salt rejection ratio (MgSO4 and NaCl); the results were also compared with those of commercial NF membranes (i.e. NF-90 and NF-270 from Dow FILMTEC). The existence of non-reactive IL in Interfacial Polymerization clearly affected the structure of the barrier layer and corresponding NF properties. The smaller ion (BMIC) simultaneously reduced permeation flux and increased salt rejection rate, while the larger ion (OMIC) exhibited an increase in permeation flux but a slight reduction in salt rejection. The demonstrated TFNC membrane exhibited 2 times higher permeation flux compared to that of NF-90 with comparable salt rejection ratio, and comparable permeation flux and salt rejection performance as those of NF-270.