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Hao Y.,Hebei University of Science and Technology | Cao Y.,Hebei University of Science and Technology | Sun B.,Hebei University of Science and Technology | Zhang Y.,Hebei University of Science and Technology | And 3 more authors.
Acta Chimica Sinica | Year: 2012

In this paper, ordered one-dimensional poly (3-hexylthiophene) (P3HT) /CdS/TiO2/ZnO core-shell nanorod arrays were fabricated. Highly ordered and vertically oriented one-dimensional ZnO nanorod arrays were electrodeposited on the indium-tin oxide (ITO) glass substrates. TiO2 sol was deposited on ZnO nanorod array by dip-coating to obtain TiO2/ZnO core-shell nanorod array. CdS nanocrystals were electrodeposited on the TiO2/ZnO core-shell nanorods to fabricate CdS/TiO2/ZnO core-shell nanorod arrays. Then a thin P3HT layer was electrodeposited on the CdS/TiO2/ZnO core-shell nanorod arrays to prepare the photoanode of the nanostructured hybrid solar cell. The photovoltaic performance of the hybrid solar cell was tested, and the mechanism of the solar cell was investigated.


Li X.,Tianjin Polytechnic University | Chen Y.,Tianjin Polytechnic University | Hu X.,Tianjin Motimo Membrane Technology Co. | Zhang Y.,Tianjin Polytechnic University | Hu L.,Tianjin Polytechnic University
Journal of Membrane Science | Year: 2014

Novel poly(vinyl alcohol) (PVA)/poly(vinylidene fluoride) (PVDF) hollow fiber composite membranes modified with nano-TiO2 were prepared by a dip-coating method and they are suitable to be utilized in dye desalination and wastewater treatment. Glutaraldehyde (GA) was used as a cross-linker for the composite polymer membrane in order to enhance the chemical, thermal as well as mechanical stabilities. The surface morphologies and chemical structures of modified membranes were observed by scanning electronic microscopy (SEM), energy dispersive spectroscopy (EDS) and FTIR spectroscopy. Zeta potential of the membrane surface was used to analyze the membrane separation performance. Separation efficiency of dye and salts through novel PVA/PVDF composite membrane was dramatically influenced by dye concentration, salts concentration, pH and temperature of feed solution. Fouling and thermal stability of the membrane were also evaluated with CR, NaCl, and Na2SO4 as model compounds. The separation datas showed that the 1g/L nano-TiO2 modified membrane presented highest performance in terms of the rejections to CR, MO, and MB being 94±2.57%, 52.1±2.45%, and 92±2.20%, respectively. And all the PVA composite membranes had no rejection to salts (NaCl, Na2SO4). Compared with PVA composite membrane, the PVA composite membrane modified with nano-TiO2 has higher separation efficiency, antifouling and thermal stability. © 2014 Elsevier B.V.


Wang J.,Tianjin Polytechnic University | Wu Y.,Tianjin Polytechnic University | Geng Q.,Qianan Environmental Protection Bureau | Zhang H.,Tianjin Polytechnic University | Li L.,Tianjin MOTIMO Membrane Technology Co.
Huagong Xuebao/CIESC Journal | Year: 2014

Based on numerical simulation, the flow field characteristics of integrated coagulation-membrane filtration process were investigated at different aeration intensities and module packing densities. According to the flocculation kinetics theory, the micro-vortex scale was introduced to analyze the flow field state. It was used to evaluate the effect of aeration intensity on flocs formation and membrane cleaning during the cleaning process. The simulation results were validated experimentally by the real-time imaging technology. When module packing density and air-water ratio were 7.38% and 15:1 respectively, mean effective energy consumption was moderate and vortex scale was sufficiently large. Moreover, under such conditions damage of flocs was not obvious, meaning that larger vortex was conducive to flocs formation. Meanwhile, a strong shear speed generated by the field near the membrane module was beneficial to membrane cleaning and hindered flocs breakage. Combining with experiment analysis, when module packing density and air-water ratio were 7.38% and 15:1 respectively, the size of flocs particle formed in the experiment was the largest, close to the micro eddy scale obtained from numerical simulation. The values of UV254 and TOC were minimum and flocculation effect was the best. © All Rights Reserved.


Wang J.,Tianjin Polytechnic University | Cheng Z.,Tianjin Polytechnic University | Jia H.,Tianjin Polytechnic University | Zhang H.,Tianjin Polytechnic University | Huang Y.,Tianjin MOTIMO Membrane Technology Co.
Huagong Xuebao/CIESC Journal | Year: 2014

Comparing with coagulation membrane filtration (C-MF) process, the circulating flocculation membrane filtration (CF-MF) process is a combination of circulating contact flocculation with membrane filtration. The differences of membrane fouling development in the two processes were investigated in this study. SUVA was used as an evaluation index of hydrophilic/hydrophobic properties for organic matters to assess the effect of process variation on SUVA as well as to find relation between SUVA and index of comprehensive membrane fouling. The results indicated that there exists a good liner relationship between SUVA in membrane filtration and membrane fouling. The higher SUVA was, the more serious membrane fouling was. In the optimal operation conditions, SUVA in membrane filtration effluent and coagulation process supernatant were 1.74 L · mg-1 · m-1 and 1.18 L · mg-1 · m-1 for CF-MF process, the removal of organic matters increased by 17% and 29%, comparing with C-MF process, indicating that the removal of hydrophobic organic matters and the control of fouling formation on membrane from them was better for CF-MF than C-MF. Comparing with C-MF process, the CF-MF is more effective for removing organic matters. With coagulant dosing of 6 mg · L-1 and reflux floc concentration of 10 mg · L-1, the removal rate of UV254 and DOC were 58.75% and 49.7% respectively. © All Rights Reserved.


Quan Q.,Tianjin Polytechnic University | Xiao C.F.,Tianjin Polytechnic University | Liu H.L.,Tianjin Polytechnic University | Zhao W.,Tianjin Polytechnic University | And 2 more authors.
Advanced Materials Research | Year: 2014

The two-dimensional braid heterogeneous-reinforced (BHR) polyvinylidene fluoride (PVDF) hollow fiber membranes which include PVDF polymer solutions (coating layer) and the two-dimensional braid as a reinforcement were prepared through the dry-wet spinning process. The influence of PVDF concentration in polymer solutions on performance of BHR hollow fiber membranes were investigated by terms of pure water flux, protein rejection, a mechanical strength test, and morphology observations by a scanning electron microscope (SEM). The results of this study indicated that the tensile strength of the BHR PVDF hollow fiber membranes was nearly 75 MPa and the hollow fiber membranes were endowed with better flexibility performance. The BHR PVDF hollow fiber membranes had a favorable interfacial bonding between the coating layer and the two-dimensional braid. The pure water flux decreased, while the rejection ratio increased with the increase of polymer concentration. © (2014) Trans Tech Publications, Switzerland.


Zhang H.,Tianjin Polytechnic University | Li X.-L.,Tianjin Motimo Membrane Technology Co. | Hu X.-Y.,Tianjin Polytechnic University | Chen Y.-B.,Tianjin Polytechnic University | Xiao C.-F.,Tianjin Polytechnic University
Gongneng Cailiao/Journal of Functional Materials | Year: 2012

The mechanochemical treatment of PVC was studied by ball mill and the structure changes of PVC was analyzed. Based on the research, the flat membranes were prepared using the PVC before and after mechanochemical treatment, respectively by thermally induced phase separation (TIPS) method. The structure and properties of membranes were studied by FT-IR, DSC and SEM. Results showed that the mechanochemical treatment eliminated the PVC pomegranate appearance structure which made PVC difficult to be processed, and the perfection of initial micro-crystal of PVC was also reduced. The water flux of the flat membrane built of PVC after mechanochemical treatment by TIPS method reached 693.6 L/(m2·h) which was much higher than that built of PVC before mechanochemical treatment with the value of only 7.1 L/(m2·h), and the fracture strength of the flat membrane was also increased.


Sun C.,Tianjin University | Xie L.-X.,Tianjin University | Sun Y.-C.,Tianjin University | Sun L.,Tianjin MOTIMO Membrane Technology Co. | Dai H.-P.,Tianjin MOTIMO Membrane Technology Co.
Huaxue Gongcheng/Chemical Engineering (China) | Year: 2015

The performance of coagulation-ultrafiltration hybrid process as a pretreatment method for desalting seawater in Bohai Bay was studied. The operating characteristics of the ultrafiltration system membrane at the flux of 50 L/(m2·h) and 57.5 L/(m2·h) were investigated. The effects of FeCl3 coagulation on the trans-membrane pressure (TMP) and effluents quality were studied. The results show that when the flux is less than 60 L/(m2·h), the long-term operation stability of coagulation-UF process at low TMP can be reached with 6 mg/L FeCl3 above 14 ℃. During the experiment, the effluent of UF was stable and wasn't impacted with the raw water quality changes. The turbidity of membrane effluent was consistently below 0.15 NTU and the silt density index (SDI15) stayed stable around 2.0. Darcy model was used to analyze the growth mechanism of the membrane resistance under different operation conditions, and the results indicate that coagulation can effectively lower the increase trend of membrane resistance, especially the irreversible resistance of membrane pore pollution. © 2015, Editorial Office of Chemical Engineering (China). All right reserved.


Sun C.,Chemical Engineering Research Center | Xie L.,Chemical Engineering Research Center | Li X.,Chemical Engineering Research Center | Sun L.,Tianjin MOTIMO Membrane Technology Co. | Dai H.,Tianjin MOTIMO Membrane Technology Co.
Desalination | Year: 2015

Performance of different pretreatment systems with ultrafiltration (UF) prior to reverse osmosis (RO) for desalting seawater was assessed in this paper. The pilot trial was operated on seawater from Bohai Bay in Tianjin using polyvinylidene fluoride (PVDF) hollow fiber UF membrane. During these experiments, membrane specific flux (SF) was calculated to evaluate the performance of UF. Results of the research showed that in a chemical enhanced backwash (CEB) period, the combination of UF with FeCl3 flocculation pretreatment was helpful in controlling the decrease of SF during the operation. Besides, the result also showed that FeCl3 flocculation/dual-stage sand filtration/UF performed effectively in terms of the stable of SF in a CEB period than FeCl3 flocculation/UF alone. In addition, water analysis was regularly performed to quantify pollutants in the effluents of different hybrid processes. According to the experiment, UF can provide product water with consistently low turbidity (0.07-0.12NTU) and low silt density index (SDI15 less than 2) levels regardless of seawater quality. Sand filtration showed good performance for turbidity removal (less than 0.5NTU in effluent), but limited effect on SDI removal (not below 4). Total organic carbon (TOC) removal up to 28% was obtained in FeCl3 flocculation/dual-stage sand filtration/UF hybrid system. © 2015 Elsevier B.V.


Patent
Tianjin Motimo Membrane Technology Co. | Date: 2012-07-02

A method for making a liquid separation membrane, including: (1) providing a polyvinylidene fluoride liquid separation membrane or polypropylene liquid separation membrane prepared by a thermally induced phase separation method as a substrate membrane, soaking the substrate membrane with water or a weak polar organic liquid to make membrane pores of the substrate membrane filled with the liquid, the soaking time being between 0.5 s and 1 min, and the weak polar organic liquid being indissolvable and compatible with the polyvinylidene fluoride liquid separation membrane or polypropylene liquid separation membrane; (2) coating a casting solution of polyvinylidene fluoride on the surface of the soaked substrate membrane obtained in step (1), and quickly soaking the substrate membrane in a coagulating bath heated to a temperature of 60-100 C. for curing to yield the liquid separation membrane.


Disclosed is a method for preparing a liquid separation membrane complexed and reinforced with polyvinylidene fluoride, comprising the following steps: subjecting a polyvinylidene fluoride liquid separation membrane or a polypropylene liquid separation membrane prepared by thermally induced phase separation, as a base membrane, to infiltration with any one of water and weakly polar organic liquids such that the pores of the base film are filled with the liquid; coating the surface of the infiltrated base membrane with a polyvinylidene fluoride casting solution and then quickly immersing the membrane into a curing bath for curing such that a liquid separation membrane complexed and reinforced with polyvinylidene fluoride is obtained. The liquid separation membrane obtained by the method both has a good mechanical property and a high retention rate, and the skin layer is not liable to peel off during use.

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