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Shen J.-N.,Zhejiang University of Technology | Ruan H.-M.,Zhejiang University of Technology | Wu L.-G.,Zhejiang GongShang University | Gao C.-J.,National Engineering Research Center for Liquid Separation Membrane
Chemical Engineering Journal | Year: 2011

Ultrafiltration (UF) has become an accepted process for drinking water treatment, but membrane fouling remains a significant problem. Polyethersulfone (PES)/SiO2 composite membranes were prepared by phase inversion method with nano-SiO2 as additive. Water contact angle measurement was conducted to investigate the hydrophilicity and surface wettability of the membranes. The effect of SiO2 nanoparticles on the membrane permeation properties, anti-fouling performances, and membrane morphologies and structures was examined and discussed. The influence of SiO2 on the water permeability, anti-fouling of the PES membranes were evaluated by raw water UF experiments. The results showed that the membrane structure was not obviously affected by addition of SiO2, and the membrane performances such as hydrophilicity and anti-fouling ability were enhanced by adding SiO2 nanoparticles. © 2011 Elsevier B.V.

Teng Y.,Zhejiang GongShang University | Wu L.,Zhejiang GongShang University | Wu L.,National Engineering Research Center for Liquid Separation Membrane | Wang T.,Zhejiang GongShang University | Du C.,Zhejiang GongShang University
2011 International Conference on Electric Technology and Civil Engineering, ICETCE 2011 - Proceedings | Year: 2011

A new type of microemulsions, ionic liquid microemulsion, was presented in this paper. In this microemulsion system, ionic liquid (1-dodecyl-3-methyl imidazoium chloride) served as the surfactant. AgCl nanoparticles were prepared by direct precipitation of silver ions with the surfactant counter ion Cl - in the water pools of C12mimCl/H2O/MMA reverse microemulsions. And then nano-AgCl/C12mimCl-PMMA hybrid membranes were prepared by situ microemulsions polymerization. The ternary phase diagram showed that C12mimCl was a good surfactant, it not only had a high solution capacity of MMA, also enhanced the solubilization of water in microemulsions significantly. The results of UV-vis and TEM proved that the formation and size of AgCl nanoparticles could be effected by changing the structure parameters of microemulsion. Meanwhile the swelling-sorption behaviors of the cyclohexane/cyclohexene in hybrid membranes were studied. The results indicated that the hybrid membranes' maximum swelling-sorption amount of cyclohexene was much larger than that of cyclohexane. All results suggested that the hybrid membranes including AgCl nanoparticles had potential applications in green chemistry. © 2011 IEEE.

Zhao H.,Zhejiang University | Qiu S.,Zhejiang University | Wu L.,Zhejiang GongShang University | Zhang L.,Zhejiang University | And 3 more authors.
Journal of Membrane Science | Year: 2014

Polyamide reverse osmosis membranes incorporating carboxy-functionalized multi-walled carbon nanotubes (MWNTs) were prepared by interfacial polymerization of metaphenylene diamine and trimesoyl chloride. The pristine MWNTs were pre-treated with mixed acids before being modified with diisobutyryl peroxide to enhance their dispersity and chemical activity. The prepared nanocomposite membranes had a 100-300. nm skin layer and the modified MWNTs were embedded within the skin layer, which was confirmed by scanning electron microscopy and transmission electron microscopy. The surface of the nanocomposite membrane was shown to be more negatively charged than bare polyamide membrane. It was shown that with an increase in the carbon nanotube loading in the membrane, the membrane morphology changed distinctly, leading to a significantly improved flux without sacrificing the solute rejection. Meanwhile, the nanocomposite membranes showed better antifouling and antioxidative properties than MWNT-free polyamide membranes, suggesting that the incorporation of modified MWNTs in membranes is effective for improving the membrane performance. © 2013 Elsevier B.V.

Qiu S.,Zhejiang University | Wu L.,Zhejiang GongShang University | Shi G.,Zhejiang University | Zhang L.,Zhejiang University | And 3 more authors.
Industrial and Engineering Chemistry Research | Year: 2010

This study was designed to prepare functionalized multiwalled carbon nanotubes (MWNTs-COOH) incorporated chitosan membrane for separation of ethanol/water mixtures by pervaporation. The pristine MWNTs were treated by mixed acid and then functionalized by diisobutyryl peroxide. The structure and property of the functionalized MWNTs were characterized by Fourier transform infrared and Raman spectroscopies and transmission electron microscopy. A series of functionalized MWNTs incorporated chitosan membranes were prepared by solution blending method. The swelling degree of the resulting membranes in ethanol/water mixtures was 6 times that of the pristine chitosan membrane. The permeation flux of the membranes increased significantly with increasing functionalized MWNTs content in blend membrane matrix in pervaporation. On the basis of the experiments of sorption equilibrium, the solubility and the diffusion coefficient of membranes in water, ethanol, and 90% ethanol/water mixtures were obtained. Compared with the calculated diffusion coefficient (D90), the measured diffusion coefficient (D90 T) in 90% ethanol/water mixtures was higher, taking M(2) for an example, D90 was 0.193 - 10-6 m2/s, and D 90 T was 0.41 - 10-6 m2/s, which indicated the functionalized MWNTs were more prone to increased water permeation when ethanol and water penetrated into the membrane simultaneously. In addition, effects of MWNTs content in the membrane matrix and operating temperature on pervaporation performances were investigated. After introducing functionalized MWNTs, the Arrhenius activation parameters for the total permeation decreased from 28.15 to 12.91 kJ/mol, which indicated that the carbon nanotubes filled membranes were easier to penetrate and exhibited higher flux performance than a pristine membrane. © 2010 American Chemical Society.

Teng Y.,Zhejiang GongShang University | Wu L.,Zhejiang GongShang University | Wu L.,National Engineering Research Center for Liquid Separation Membrane | Wang T.,Zhejiang GongShang University | Du C.,Zhejiang GongShang University
2011 International Conference on Remote Sensing, Environment and Transportation Engineering, RSETE 2011 - Proceedings | Year: 2011

AgCl/C12mimCl-PMMA inorganic-organic hybrid membranes were prepared via ionic liquid-microemulsion polymerization. And in this microemulsion system, ionic liquid (1-dodecyl-3-methyl imidazoium chloride) served as the surfactant, methyl methacrylate served as the oil. The morphology, particle size and size distribution were characterized by UV-vis and TEM. The results revealed that the AgCl nanoparticles in microemulsion were spherical or sphere-like, the average diameter was below 8nm and its attribution was relatively narrow. The SEM showed AgCl nanoparticles were evenly dispersed in hybrid membranes. The swelling-sorption behaviors of the cyclohexane/cyclohexene in hybrid membranes were studied. The results indicated that the hybrid membranes' maximum swelling-sorption amount of cyclohexene was up to 447, which was larger than that of cyclohexane(96). © 2011 IEEE.

Shen J.N.,Zhejiang University of Technology | Yu C.C.,Zhejiang University of Technology | Ruan H.M.,Zhejiang University of Technology | Gao C.J.,National Engineering Research Center for Liquid Separation Membrane | Van der Bruggen B.,Catholic University of Leuven
Journal of Membrane Science | Year: 2013

Carbon nanotube enhanced thin-film nanocomposite membranes were prepared by incorporating carbon nanotubes (CNTs) into the active layers of membranes used for water treatment. For inclusion into these active layers, a grafting procedure for carbon nanotubes was set up to increase their hydrophobicity. Multiwalled carbon nanotubes (MWNTs) grafted by poly(methyl methacrylate) (PMMA) were synthesized via a microemulsion polymerization of methyl methacrylate (MMA) in the presence of acid-modified multiwalled carbon nanotubes (c-MWNTs). Subsequently, polyamide thin-film nanocomposite (TFN) membranes containing PMMA-MWNTs were prepared via interfacial polymerization. Morphology studies demonstrate that MWNTs have been successfully embedded into the active polyamide layer. The rejection of Na2SO4 was high (99%), and the water flux was about 62% increased compared to the thin-film composite membrane when using 2g/L piperazine (PIP) in the aqueous phase, 4g/L trimesoyl chloride (TMC) and 0.67g/L PMMA-MWNTs in the organic phase, which demonstrates that PMMA-MWNTs significantly improve selectivity and permeability. © 2013 Elsevier B.V.

Shen J.-N.,Zhejiang University of Technology | Yu J.,Zhejiang University of Technology | Chu Y.-X.,Zhejiang University of Technology | Zhou Y.,National Engineering Research Center for Liquid Separation Membrane | Chen W.-J.,Zhejiang University of Technology
Advanced Materials Research | Year: 2012

Polyacrylonitrile/montmorillonite (PAN/MMT) nanocomposite with amidoxime functionality was prepared from acrylonitrile monomer(AN) and montmorillonite(MMT) through in-situ intercalation polymerization. Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction patter (XRD) were employed to characterize the obtained Na-MMT, Organ-MMT, PAN/MMT, APAN/MMT. Effects of preparing conditions of APAN/MMT on adsorption of uranium were investigated. The FT-IR spectra show that the new absorption band at 1653 cm -1( C NH2) appears and the absorption band at 2243 cm -1(-CN) disappears on the spectrum of APAN/MMT, it indicates that the AN and MMT are successfully polymerized by in-situ polymerization and the PAN/MMT is amidoxime functionalized. The APAN/MMT nanocomposite completely lose the X-ray diffraction. The adsorption results show that the obtained APAN-MMT gives uranium adsorption capacity of 3.06 mg.g- 1 under following conditions: uranium ion concentration of 10 mg/L, AM mass concentration of 80.0%, initiator of 4.5%, polymerization temperature of 70 °C, polymerization time of 3 h, pH of 7 and amidoxime functionalized reaction time of 2 h. © (2012) Trans Tech Publications.

Shen J.,Zhejiang University of Technology | Lin J.,Catholic University of Leuven | Yu J.,Zhejiang University of Technology | Jin K.,National Engineering Research Center for Liquid Separation Membrane | And 2 more authors.
Chemical Engineering and Processing: Process Intensification | Year: 2013

2-Amino-1-propanol (AMP) is a key intermediate compound in the production of antibiotics, with increasing demand in industry. In this study, we propose a newly designed bipolar membrane electrodialysis (BMED) system with a novel three-compartment configuration for the processing of AMP from the AMP sulphate solution. The operational parameters were investigated for optimizing the performance of this novel BMED stack, compared to the traditional two-compartment BMED stack in the pilot scale experiment. The experimental results indicate that this novel type of BMED stack offers a better performance for AMP processing than the conventional two-compartment BMED stack. The optimum performance was observed at the current density ranging from 40 to 60mAcm-2 and a spacer thickness of 0.70mm. The corresponding current efficiency and energy consumption reached up to 53.4% and 3.135kWhkg-1, respectively. The two-compartment BMED stack was found to have a low current efficiency (39.8%) and a high energy consumption (3.864kWhkg-1). Pilot-scale experiments for an industrial application of this novel BMED stack have been applied, demonstrating that the BMED process is feasible and economically alternative for AMP purification in the industry. © 2013 Elsevier B.V.

Zou K.,Zhejiang University | Wang L.,Tangshan Teachers College | Zhang L.,Zhejiang University | Chen H.,Zhejiang University | And 2 more authors.
Huagong Xuebao/CIESC Journal | Year: 2012

A nanofiltration (NF) composite membrane, with an ultra-thin skin layer, was prepared through interfacial polymerization on a polysulfone support with trimesoyl chloride (TMC) and a key aqueous monomer trimesoyl piperazine (TMPIP) hydrochloride with branched triimine structure, which was designed and synthesized based on the principle of interfacial polymerization of TMC and piperazine (PIP). Fourier transform infrared spectroscopy (FTIR) was combined with scanning electron microscope (SEM) to characterize the chemical composition and structure of the skin layer. The results showed that an ultra-thin poly(piperazineamide) skin layer, around 100 nm thick, was formed on the surface of support membrane. Compared with the performance of TMC/PIP composite membrane against PEG 200, the improved performance of TMC/TMPIP composite membrane was attributed to its high crosslinking and ultra-thin skin layer. The performance for aqueous solution of different salts was investigated, and it was found that the rejection and flux were both better than those of TMC/PIP composite membrane, with the same rejection order. © All Rights Reserved.

Tao J.,Hefei University of Technology | Huang N.,Hefei University of Technology | Li J.,Hefei University of Technology | Li J.,National Engineering Research Center for Liquid Separation Membrane | And 4 more authors.
Journal of Physical Chemistry Letters | Year: 2014

Despite the important role and potential application of charged cylindrical polyelectrolytes, biomacromolecules, and self-assembles, salt-modulated organization of those 1D charged nanostructures remains a topic relatively unexplored with an obscure underlying mechanism. In this Letter, the aggregation of oriented nanotubes self-assembled by ionic aromatic oligoamide in aqueous solution of NaCl over a wide concentration range is probed via small-angle X-ray scattering and a transmission electron microscope. The arrangement of nanotubes undergoes order-disorder transition sequences from an ordered rectangular phase to hexagonal packing and then to a lamellar gel. The observed transitions are understood by ionic effects on the electrostatic interaction between charged nanotubes and osmotic pressure due to ion partitioning. Above the physiological condition, electrostatic interactions are largely screened by the salts, while osmotic effects start to regulate the aggregation behavior and concomitantly deform the nanotubes. The study demonstrates rich phase behaviors of ordered, charged 1D nanostructures by tuning the ionic strength and underlying key physical principles. © 2014 American Chemical Society.

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