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Graft modification of ZnO nanoparticles with silane coupling agent KH570 in mixed solvent 被引量:10
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作者 马书蕊 施利毅 +2 位作者 冯欣 虞伟钧 鲁波 《Journal of Shanghai University(English Edition)》 CAS 2008年第3期278-282,共5页
The reaction of ZnO nanoparticles grafted with KH570 silane coupling agent was carried out in water-alcohol mixed solvent. Several characterization methods were applied to analyzing the results of surface modification... The reaction of ZnO nanoparticles grafted with KH570 silane coupling agent was carried out in water-alcohol mixed solvent. Several characterization methods were applied to analyzing the results of surface modification such as Soxhlet extraction, Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), thermogravimetry (TG), differential scanning calorimetry (DSC) and zeta potential (ζ). The results of FT-IR and TG-DSC show that the desired reaction chains have been covalently bonded on the surface of ZnO nanoparticles. Zetasizer results reveal that the maximal absolute value of ζ of the modified ZnO particles in acetone medium was 67.0 mV, which was much higher than that of the unmodified ZnO particles. So the surface of nanosized ZnO changed from hydrophilicity to hydrophobicity and the dispersity of ZnO nanoparticles were improved simultaneously. Finally, the mechanism of graft modification was discussed. 展开更多
关键词 ZnO nanoparticles SURFACE silane coupling agent graft modification
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Graft Modification of N,N'-methylene- bisacrylamide onto Silk in the Presence of Air 被引量:1
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作者 陈国强 邢铁玲 周翔 《Journal of Donghua University(English Edition)》 EI CAS 2001年第3期75-79,共5页
The graft modification of N, N'-methylene-bisacrylamide (NNMBAA) onto silk using eerie ammonium sulfate, potassium persulfate, ammonium persulfate and 2, 2-azobis (isobutyronitrile) as the initiators has been stud... The graft modification of N, N'-methylene-bisacrylamide (NNMBAA) onto silk using eerie ammonium sulfate, potassium persulfate, ammonium persulfate and 2, 2-azobis (isobutyronitrile) as the initiators has been studied in the presence of air. To establish reaction conditions for the graft modification of NNMBAA onto silk, the effect of different variables such as the initiator concentration, monomer concentration, acetic acid concentration, time of polymerization, reaction temperature and liquor ratio (fabric: liq.) have been studied. The optimum grafting conditions were found. As evidence of grafting, analyses of amino acid composition and alkali solubility have been carried out. Grafting caused changes in amino acid composition and alkali solubility of silk. The observation has been explained in relation to structural changes in the grafted silk. 展开更多
关键词 graft modification Silk fabric N N'-methylene-bisacrylamide.
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Polymer grafting modification of the surface of nano silicon dioxide 被引量:5
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作者 WeiWu ShouciLu 《Journal of University of Science and Technology Beijing》 CSCD 2002年第6期426-430,共5页
Based on the composite modification technology of the surface of nano Silicondioxide by non-soap emulsion polymerization, it is verified that there are polymer grafted on thesurface of nano silicon dioxide. The modifi... Based on the composite modification technology of the surface of nano Silicondioxide by non-soap emulsion polymerization, it is verified that there are polymer grafted on thesurface of nano silicon dioxide. The modification mechanism and the bonding status on the surface ofnano silicon dioxide after modification were suggested via the results of the infrared spectrum,transmission electronic microscope photograph and X-ray photoelectron spectrum. The hydroxyl formedby hydrolyzing of silane coupling agent reacts with hydroxyl on the surface of nano silicon dioxideto form Si-O-Si bonds by losing water molecules and hence the double bonds are introduced onto thesurface of nano silicon dioxide. The surface of nano silicon dioxide is grafted with polymer throughfree radical polymerization between the double bonds on the surface of nano silicon dioxide andstyrene under the action of initiating agent. The dispersibility of nano silicon dioxide and thecontrollability of surface modification of nano silicon dioxide can be greatly improved by themodification process. 展开更多
关键词 nano silicon dioxide grafting modification MECHANISM silane couplingagent STYRENE
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Grafting modification on the surface of titanium dioxide by polystyrene
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作者 WeiWu ShouciLu +2 位作者 JianfengChen LeiShao CheeKingTan 《Journal of University of Science and Technology Beijing》 CSCD 2003年第6期52-56,共5页
Based on the technology of titanium dioxide grafting modification withpolystyrene (PS), the modification mechanisms are studied and the polystyrene-grafting states on thesurface of titanium dioxide have been set up. U... Based on the technology of titanium dioxide grafting modification withpolystyrene (PS), the modification mechanisms are studied and the polystyrene-grafting states on thesurface of titanium dioxide have been set up. Under the synergistic actions of mechanical force,chemistry and heat, macromolecular free radicals of PS are created, at the same time, the O-O bondsof titanium dioxide are broken and the oxide free radicals produced, and the numbers of oxygen atomare increased and crystal lattice defects rich electrons are formed on the surface of titaniumdioxide. The radical polymerization is the main reaction between PS and titanium dioxide and C-Obonds form in the process of modification. Multi-sites chemical adsorption also exists besidesgrafting between PS and titanium dioxide. 展开更多
关键词 titanium dioxide POLYSTYRENE grafting modification CHARACTERIZATION radical polymerization reaction
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Synthesis and Characterization of Lignin Grafting Modification-based Aliphatic Superplasticizer
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作者 马双平 丁庆军 +1 位作者 ZHOU Fen ZHU Huaxiong 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2018年第3期661-668,共8页
Lignin as the main component of black liquor is generally employed to modify aliphatic superplasticizer(AFS). However, the modification effect is hard to evaluate correctly due to the uncertain molecular structure o... Lignin as the main component of black liquor is generally employed to modify aliphatic superplasticizer(AFS). However, the modification effect is hard to evaluate correctly due to the uncertain molecular structure of lignin and the disturbance from the complexity of black liquor compositions. In this paper, the purified lignin via acid precipitation from straw black liquor is used to modify AFS. The modified AFS named as LAFS for short presents lower molecular mass than AFS. It is assumed that it is due to the single active site of guaiacol segments in lignin by which lignin graft modifies AFS in virtue of methylolation reaction. In order to verify this assumption, guaiacol and dihydro eugenol as the typical segments of lignin macromolecule were selected, respectively, as the simplified model compounds of lignin to modify AFS, and corresponding products are abbreviated in GAFS and DAFS. Both GAFS and DAFS show the lower molecular mass than unmodified AFS. FTIR and TG-DTG analyses prove that lignin is successfully grafted onto AFS. The graft modification of lignin results in a decrease in electrostatic epulsion, but an enhanced steric hindrance. Therefore, although the replacement rate of lignin in LAFS was about 23.3%, the dispersion performance was only slightly affected. 展开更多
关键词 grafting modification lignin aliphatic superplasticizer model compound dispersion performance
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Study on the Surface Modification of Hydrophobic Polyacrylate Intraocular Lens 被引量:2
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作者 TANG Hui-qin WANG Gui-qin GU Han-qing 《Chinese Journal of Biomedical Engineering(English Edition)》 2013年第1期29-36,共8页
In this study, the polyacrylate intraocularr lens is irradiated by argon ion which can produce free radicals. In order to obtain better hydrophilic and lower platelets adhesion, monomer vinyl pyrrolidone (NVP) is graf... In this study, the polyacrylate intraocularr lens is irradiated by argon ion which can produce free radicals. In order to obtain better hydrophilic and lower platelets adhesion, monomer vinyl pyrrolidone (NVP) is grafted onto the hydrophobic polyacrylate intraocular lens surface in a certain reaction conditions. Specific changes in intraocular lens are detected by static contact angle (CA), scanning electron microscope (SEM) and light transmittance. The results show that this surface modification can greatly improve its hydrophilic character and surface formation. 展开更多
关键词 hydrophobic polyacrylate intraocular lens vinyl pyrrolidone argon ion irradiation graft surface modification
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Enhanced Electrical Properties of Styrene-grafted Polypropylene Insulation for Bulk Power Transmission HVDC Cables
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作者 Hao Yuan Shixun Hu +8 位作者 Yao Zhou Chao Yuan Wenbo Song Qing Shao Hongwei Shi Juan Li Jun Hu Qi Li Jinliang He 《CSEE Journal of Power and Energy Systems》 SCIE EI CSCD 2024年第1期361-370,共10页
Polypropylene(PP)is considered to be a rather promising material for HVDC cable insulation.Grafting modification has proved to be an effective method on the electrical property improvements of PP.This paper reports on... Polypropylene(PP)is considered to be a rather promising material for HVDC cable insulation.Grafting modification has proved to be an effective method on the electrical property improvements of PP.This paper reports on the highlyenhanced electrical properties of styrene-grafted polypropylene(PP-g-St)and their related mechanism.The influence of grafting styrene on crystallization structures,thermal properties and electrical properties of PP-g-St are characterized and analyzed.These results show that PP-g-St exhibits remarkably enhanced DC volume resistivity,suppressed space charge accumulation and improved DC breakdown strengths as compared to PP.Crystallization observation shows PP-g-St has small,imperfect spherulites with indistinct boundaries,which is strongly correlated to enhanced electrical properties.This study provides an effective grafting strategy to design high-performance HVDC cable insulation materials for bulk power transmission systems. 展开更多
关键词 Electrical properties grafting modification POLYPROPYLENE STYRENE
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Enhanced permeability and biofouling mitigation of forward osmosis membranes via grafting graphene quantum dots
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作者 Nan Li Yumeng Zhang +3 位作者 Peng Li Bo Zhu Wei Wang Zhiwei Xu 《Frontiers of Chemical Science and Engineering》 SCIE EI CSCD 2023年第10期1470-1483,共14页
In this paper,graphene oxide quantum dots with amino groups(NH_(2)-GOQDs)were tailored to the surface of a thin-film composite(TFC)membrane surface for optimizing forward osmosis(FO)membrane performance using the amid... In this paper,graphene oxide quantum dots with amino groups(NH_(2)-GOQDs)were tailored to the surface of a thin-film composite(TFC)membrane surface for optimizing forward osmosis(FO)membrane performance using the amide coupling reaction.The results jointly demonstrated hydrophilicity and surface roughness of the membrane enhanced after grafting NH_(2)-GOQDs,leading to the optimized affinity and the contact area between the membrane and water molecules.Therefore,grafting of the membrane with a concentration of 100 ppm(TFC-100)exhibited excellent permeability performance(58.32 L·m^(–2)·h^(–1))compared with TFC membrane(16.94 L·m^(–2)·h^(–1)).In the evaluation of static antibacterial properties of membranes,TFC-100 membrane destroyed the cell morphology of Escherichia coli(E.coli)and reduced the degree of bacterial adsorption.In the dynamic biofouling experiment,TFC-100 membrane showed a lower flux decline than TFC membrane.After the physical cleaning,the flux of TFC-100 membrane could recover to 96%of the initial flux,which was notably better than that of TFC membrane(63%).Additionally,the extended Derjaguin–Landau–Verwey–Overbeek analysis of the affinity between pollutants and membrane surface verified that NH_(2)-GOQDs alleviates E.coli contamination of membrane.This work highlights the potential applications of NH_(2)-GOQDs for optimizing permeability and biofouling mitigation of FO membranes. 展开更多
关键词 forward osmosis membrane graphene oxide quantum dots graft modification anti-fouling membrane XDLVO theory
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Preparation and Characterization of the Modified Polyvinylidene Fluoride (PVDF) Hollow Fibre Microfiltration Membrane 被引量:2
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作者 Laizhou SONG Zunju ZHANG +1 位作者 Shizhe SONG Zhiming GAO 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2007年第1期55-60,共6页
A novel thermally induced graft polymerization technique was used to modify a polyvinylidene fluoride (PVDF) hollow fibre microfiltration membrane. An artificial neural network (ANN) was applied to optimize the pr... A novel thermally induced graft polymerization technique was used to modify a polyvinylidene fluoride (PVDF) hollow fibre microfiltration membrane. An artificial neural network (ANN) was applied to optimize the prepared condition of the membrane. The optimized dosing of acrylic acid (AA), acrylamide (AM), N, N'- methylenebisacrylamide (NMBA) and potassium persulphate (KSP) designed by ANN was that AA was 40.63 ml/L; AM acted as 6.25 g/L; NMBA was 1.72 g/L and KSP was 1.5 g/L, respectively. The thermal stability of the PVDF modified hollow fibre membrane (PVDF-PAA) was investigated by thermogravimetric (TG) and differential scanning calorimetry (DSC) analysis. The polycrystallinity of the PVDF-PAA membrane was evaluated by X-ray diffraction (XRD) analysis. The complex formation of the modified membrane was ascertained by Fourier transform infrared spectroscopy (FTIR). The morphology of the PVDF-PAA membrane was studied by environmental scanning electron microscopy (ESEM). The surface compositions of the membrane were analyzed by X-ray photoelectron spectroscopy (XPS). The adsorption capacity of Cu^2+ ion on the PVDF-PAA hollow fibre membrane was also investigated. 展开更多
关键词 Microfiltration hollow fibre membrane graft polymerization modification Acrylic acid Polyvinylidene fluoride Cu^2+ ion
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