Showing papers by "Congjie Gao published in 2009"
TL;DR: In this paper, multi-walled carbon nanotubes (MWNTs) functionalized by isocyanate and isophthaloyl chloride groups were synthesized via the reaction between carboxylated carbon Nanotubes and 5-isocyanato-isophthoric chloride (ICICIC).
321 citations
TL;DR: In this paper, an interfacially polymerized polyamide thin film composite membrane was modified by electrostatic self-assembly of polyethyleneimine on the membrane surface, and the modified membrane showed significantly improved antifouling properties.
181 citations
TL;DR: In this article, soluble polyelectrolyte complexes (PECs) between chitosan (CS) and CMCNa were synthesized in aqueous hydrochloric acid (HCl) and obtained in their solid form.
130 citations
TL;DR: In this article, the structure-property relationship of thin-film composite polyamide membranes was studied and several reasonable suggestions were made for tailoring special separation performance and surface properties of the composite membranes, and the results showed that the polyacyl chloride structure strongly influences the reverse osmosis performance, surface properties and chlorine stability.
115 citations
TL;DR: Aromatic-cycloaliphatic polyamide thin-film composite (TFC) reverse osmosis (RO) membranes with improved chlorine resistance as well as good RO performance were developed by the interfacial polymerization of m-phenylenediamine-4-methyl (MMPD) and cyclohexane-1,3,5-tricarbonyl chloride (HTC) on polysulfone supporting film.
107 citations
TL;DR: In this article, the performance of thin-film composite polyamide-urethane seawater reverse osmosis membrane prepared by interfacial polymerization of m-phenylenediamine (MPD) and 5-chloroformyloxyisophthaloyl chloride (CFIC) was investigated.
97 citations
TL;DR: In this paper, a three-compartment bipolar membrane electrodialysis (BMED) configuration was used to produce tartaric acid in a laboratory-scale setting. But, due to the relatively low solubility of bitartrate, the three compartments configuration was not preferred for weak acid production.
79 citations
TL;DR: In this article, a reverse osmosis composite membrane with extra-thin separation layer was prepared by the interfacial polymerization (IP) of metaphenylene diamine (MPD) with trimesoyl chloride (TMC) on the surface of polysulfone (PS) support membrane.
Abstract: In this study, reverse osmosis (RO) composite membrane with extra-thin separation layer was prepared by the interfacial polymerization (IP) of metaphenylene diamine (MPD) with trimesoyl chloride (TMC) on the surface of polysulfone (PS) support membrane. The properties and structures of skin layer of RO composite membranes were characterized by FTIR and SEM, it was found that IP had occurred and the separation layer was formed. The effects of the monomer concentration on membrane flux and salt rejection were investigated, and the optimum concentration of MPD and TMC were 2 and 0.3% (w/v), respectively. To improve flux, the phase-transfer catalyst was added to the water phase, and the effects were remarkable when the concentration of MPD was low, in which both salt rejection and flux increased by 20% than initial results. When some of the hydrophilic additives such as alcohols and phenols were added into water phase, the flux of the prepared membrane increased from 13.03 to 33.42 L/(m2 h) without loss in salt rejection. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
68 citations
TL;DR: Asymmetric and charged ultrafiltration membranes were prepared from blends with synthesized polyacrylonitrile (PAN) and hydrophilically modified polyacanitrile by the classical phase inversion technique in water as mentioned in this paper.
39 citations
31 citations
TL;DR: In this article, a positively charged composite NF membrane was prepared using a copolymer graft of trimethylallylammonium chloride onto chitosan as the top selective layer, a poly(acrylonitrile (PAN) ultrafiltrationmembrane as the support layer and toluene diisocyanate (TDI) as the cross-linking reagent.
TL;DR: In this article, the combined membrane process of electrodialysis (ED) and reverse osmosis (RO) was carried out to recover the l -tryptophan from its crystallization wastewater which had around 15% impurity of NaCl salt.
TL;DR: In this article, a novel pervaporation (PV) membranes for ethanol dehydration were prepared by blend polyvinyl alcohol (PVA) and carboxymethyl chitosan (CMCS), followed by the crosslinking reaction with glutaraldehyde; the structure and miscibility of the blend membranes were characterized by Fourier transform infrared, X-ray diffraction, and differential scanning calorimetry; the results indicated that the blends were miscible.
Abstract: Novel pervaporation (PV) membranes for ethanol dehydration were prepared by blend poly(vinyl alcohol) (PVA) and carboxymethyl chitosan (CMCS), followed by the crosslinking reaction with glutaraldehyde; the structure and miscibility of the blend membranes were characterized by Fourier transform infrared, X-ray diffraction, and differential scanning calorimetry; the results indicated that the blends were miscible. The effect of feed concentration, operation temperature, crosslinking agent content, etc. on sorption performance and PV performance of the blend membrane is investigated. The membrane of CMCS/PVA blend ratio of 8 : 2 exhibited a high separation factor of 2959 with a reasonably high water flux value of 0.14 kg m−2h−1 at the azeotropic feed composition (95 wt % of ethanol) at a temperature of 45°C. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Patent•
09 Dec 2009
TL;DR: In this article, a method for reducing scaling between the oil field oil extraction transportation system and stratum is proposed. But the method is not suitable for the use of water for diluting the polymer mother liquor.
Abstract: The invention relates to a method for reducing scaling between the oil field oil extraction transportation system and stratum. Produced water is processed by oil removal and air floatation followed by being removed of solid suspended particles by a filter and of impurity in water by a dead end ultrafiltration membrane separation device, and the ultrafiltration produced water is introduced into a nanofiltration membrane separation device to obtain nanofiltration softened water of the produced water; nanofiltration softened water of clear water is prepared; nanofiltration softened water of clear water and nanofiltration softened water of the produced water are fully mixed by a static mixer to be taken as injected water or water used for preparing polymer mother liquor; nanofiltration softened water of clear water and nanofiltration softened water of the produced water are fully mixed to take as oil extraction re-injection water or water used for diluting the polymer mother liquor. The invention has the advantages that scaling components are radically removed, and the water quality after processing does not harm the stratum, thus improving oil displacement efficiency and oil field extraction efficiency, realizing zero emission of waste water, and having good economic and environmental benefits.
TL;DR: Based on trans-membrane streaming potentials of two polyamide nanofiltration membranes (NF90 and NF) measured in a given series of electrolyte solutions (NaCl, KCl, CaCl2, Na2SO4 and MgSO4), the corresponding zeta potential and charge density were estimated by means of the Helmholtz-Smoluchowski equation and the Gouy-Chapmann double-electric layer theory.
Abstract: In this paper, the overall charged behavior of polyamide nanofiltration membranes, including their skin-layer and support-layer, was explored by electrokinetic method. Based on trans-membrane streaming potentials of two polyamide nanofiltration membranes (NF90 and NF) measured in a given series of electrolyte solutions (NaCl, KCl, CaCl2, Na2SO4 and MgSO4), respectively, the corresponding zeta potential and charge density were estimated by means of the Helmholtz–Smoluchowski equation and the Gouy–Chapmann double-electric layer theory. The experimental results show that the factors, such as concentration of electrolyte solution, type and valence of ions, have an important influence on the charged behavior of polyamide nanofiltration membranes. Furthermore, it was also found that the relationship between the charge densities and the feed solution concentration agreed well with Freundlich adsorption isotherms under certain testing conditions. Furthermore, it was confirmed that charge formation of polyamide na...