The surface of nano-TiO_2 was encapsulated with hydroxyl-propyl-methyl cellulose(HPMC),and then cograftedwith acrylates.Conditions of absorbing and grafting have been studied.Modified nano-TiO_2 particles were charact...The surface of nano-TiO_2 was encapsulated with hydroxyl-propyl-methyl cellulose(HPMC),and then cograftedwith acrylates.Conditions of absorbing and grafting have been studied.Modified nano-TiO_2 particles were characterized byFT-IR spectra,TEM and TG analysis.It was convinced from FT-IR studies that both methyl methacrylate(MMA)and butyl-methacrylate(BMA)were co-grafted onto the surface of nano-TiO_2 particles.TEM images show that the surface of nano-TiO_2 particles was successfully modified by a thick layer of film-like polymer.TG results demonstrate that the decompositiontemperature of HPMC-g-PMMA/PBMA,which has been grafted onto the surface of nano-TiO_2,is 56.9 K higher than that ofHPMC-g-PMMA/PBMA.展开更多
The nano-TiO_2 particles were prepared by liquid hydrolysis method and characterized using XRD. Its antibacterial activity against two representative bacterial, Escherichia eoli and Staphylococcus aureus, was also stu...The nano-TiO_2 particles were prepared by liquid hydrolysis method and characterized using XRD. Its antibacterial activity against two representative bacterial, Escherichia eoli and Staphylococcus aureus, was also studied. The experimental results showed that the nano-TiO_2 caleinated at 600-700℃ contained the obvious anatase phase and exerted exeeUent antibacterial activity. The feature of antibacterial activity of nano- TiO_2 was non-strains specificity and exerted best antibacterial activity at concentration of 0.8 g/L.展开更多
纳米 Ti O2 改性不饱和聚酯树脂 ,其目的是对不饱和聚酯进行同时增韧增强改性。用“反应法”制备的纳米 Ti O2 /UPR,在纳米 Ti O2 与 UPR之间产生的新化学键将纳米 Ti O2 粒子接入 UPR长链上 ,这种新的结构决定了纳米 Ti O2 /UPR的性能...纳米 Ti O2 改性不饱和聚酯树脂 ,其目的是对不饱和聚酯进行同时增韧增强改性。用“反应法”制备的纳米 Ti O2 /UPR,在纳米 Ti O2 与 UPR之间产生的新化学键将纳米 Ti O2 粒子接入 UPR长链上 ,这种新的结构决定了纳米 Ti O2 /UPR的性能。研究结果表明 ,纳米 Ti O2 /UPR的反应活性高于 UPR,纳米 Ti O2 /UPR的冲击韧性和弯曲强度较 UPR分别提高 46%和 5 5 % ,纳米 Ti O2 /UPR的耐热性及介电性与展开更多
Nano-F-/Ce3+/TiO2 particles were prepared by hydrolysis of tetrabutyl titanate in a mixed CF3COOH-Ce(NO3)3-H2O solution. The photocatalytic decomposition of methylene blue in aqueous solution was used to evaluate thei...Nano-F-/Ce3+/TiO2 particles were prepared by hydrolysis of tetrabutyl titanate in a mixed CF3COOH-Ce(NO3)3-H2O solution. The photocatalytic decomposition of methylene blue in aqueous solution was used to evaluate their photocatalytic activities. The powders were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersion X-ray spectrum (EDS), and Brunauer-Emmett-Teller (BET) surface area analysis. The results showed that F- and Ce3+ were doped into TiO2. The appropriate content of fluorine and cerium were 2.0% and 1.0% (atom fraction) respectively. The codoped nano-F-/Ce3+/TiO2 particles had higher BET specific surface area, smaller crystallite size and higher photocatalytic activity than those of undoped TiO2 particles.展开更多
The electrochemical impedance spectroscopy （EIS） was used to evaluate the water transport and dielectric properties of polyurethane films filled with nano-TiO2 at different pigment/base （P/B） values in 0.5 mol/L N...The electrochemical impedance spectroscopy （EIS） was used to evaluate the water transport and dielectric properties of polyurethane films filled with nano-TiO2 at different pigment/base （P/B） values in 0.5 mol/L NaCl solutions. EIS results were compared with gravimetric measurements on the freestanding films. The amount of water absorption showed great discrepancy between the two methods. The diffusion coefficient in the polyurethane film with P/B：30% was the smallest among those filled with nano-TiO2 pigments. The dielectric constant ε of the polyurethane varnish film obtained from the initial capacitance was in the range of typical values of polymers. SEM was used to measure the distribution of nano-TiO2 particles in the polyurethane films.展开更多
Nano-TiO2 was coated with A12O3,SiO2 and silane coupling agent by chemical liquid deposition.The coating was characterized by Raman spectroscopy,XRD,TEM and FT-IR.The coating content and anti-ultraviolet capacity of n...Nano-TiO2 was coated with A12O3,SiO2 and silane coupling agent by chemical liquid deposition.The coating was characterized by Raman spectroscopy,XRD,TEM and FT-IR.The coating content and anti-ultraviolet capacity of nano-TiO2 were measured by XRF and UV-vis spectrometer.The results show that dense coatings containing 5% Al2O3 or SiO2 can be obtained by mixing slurry at pH 10,adding coating reagent and neutralization reagent into the slurry for 60 min at 85?95 ℃,and finally aging for 120 min.Noncrystal SiO2 was coated on the surface of nano-TiO2 to form silica gel polymer with a Ti—O—Si bond,while aluminum compound exists in the form of AlOOH and part Al(OH)3.The integrated dense film can shield photocatalysis effectively.The inorganic coating film can increase the wettability for xylene and stability in water.The surface modification of nano-TiO2 will not impair its ability for anti-ultraviolet radiation,and more short band ultraviolet radiation can be absorbed.In addition,the optimal coating amount of silane coupling agent should be less than 3% and the best wettability for xylene can be reached when the amount is 1.2%.展开更多
基金This work was funded by the Natural Science Fund of Anhui Educational Committeethe Youth Fund of Anhui Normal University.
文摘The surface of nano-TiO_2 was encapsulated with hydroxyl-propyl-methyl cellulose(HPMC),and then cograftedwith acrylates.Conditions of absorbing and grafting have been studied.Modified nano-TiO_2 particles were characterized byFT-IR spectra,TEM and TG analysis.It was convinced from FT-IR studies that both methyl methacrylate(MMA)and butyl-methacrylate(BMA)were co-grafted onto the surface of nano-TiO_2 particles.TEM images show that the surface of nano-TiO_2 particles was successfully modified by a thick layer of film-like polymer.TG results demonstrate that the decompositiontemperature of HPMC-g-PMMA/PBMA,which has been grafted onto the surface of nano-TiO_2,is 56.9 K higher than that ofHPMC-g-PMMA/PBMA.
基金Funded by the Research Fund of Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province(No.AE201037the Foundation for Talent Recruitment of Yancheng Institute of Technology(No.XKR2011007)
文摘The nano-TiO_2 particles were prepared by liquid hydrolysis method and characterized using XRD. Its antibacterial activity against two representative bacterial, Escherichia eoli and Staphylococcus aureus, was also studied. The experimental results showed that the nano-TiO_2 caleinated at 600-700℃ contained the obvious anatase phase and exerted exeeUent antibacterial activity. The feature of antibacterial activity of nano- TiO_2 was non-strains specificity and exerted best antibacterial activity at concentration of 0.8 g/L.
文摘纳米 Ti O2 改性不饱和聚酯树脂 ,其目的是对不饱和聚酯进行同时增韧增强改性。用“反应法”制备的纳米 Ti O2 /UPR,在纳米 Ti O2 与 UPR之间产生的新化学键将纳米 Ti O2 粒子接入 UPR长链上 ,这种新的结构决定了纳米 Ti O2 /UPR的性能。研究结果表明 ,纳米 Ti O2 /UPR的反应活性高于 UPR,纳米 Ti O2 /UPR的冲击韧性和弯曲强度较 UPR分别提高 46%和 5 5 % ,纳米 Ti O2 /UPR的耐热性及介电性与
基金the Natural Science Foundation of Hebei Province (203364)the Natural Science Foundation of Hebei University of Science and Technology (XL2006038)
文摘Nano-F-/Ce3+/TiO2 particles were prepared by hydrolysis of tetrabutyl titanate in a mixed CF3COOH-Ce(NO3)3-H2O solution. The photocatalytic decomposition of methylene blue in aqueous solution was used to evaluate their photocatalytic activities. The powders were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersion X-ray spectrum (EDS), and Brunauer-Emmett-Teller (BET) surface area analysis. The results showed that F- and Ce3+ were doped into TiO2. The appropriate content of fluorine and cerium were 2.0% and 1.0% (atom fraction) respectively. The codoped nano-F-/Ce3+/TiO2 particles had higher BET specific surface area, smaller crystallite size and higher photocatalytic activity than those of undoped TiO2 particles.
基金supported by the National Natural Science Foundation of China(No.50499334)
文摘The electrochemical impedance spectroscopy （EIS） was used to evaluate the water transport and dielectric properties of polyurethane films filled with nano-TiO2 at different pigment/base （P/B） values in 0.5 mol/L NaCl solutions. EIS results were compared with gravimetric measurements on the freestanding films. The amount of water absorption showed great discrepancy between the two methods. The diffusion coefficient in the polyurethane film with P/B：30% was the smallest among those filled with nano-TiO2 pigments. The dielectric constant ε of the polyurethane varnish film obtained from the initial capacitance was in the range of typical values of polymers. SEM was used to measure the distribution of nano-TiO2 particles in the polyurethane films.
基金Project(2002126) supported by the Chongqing Science Committee,China
文摘Nano-TiO2 was coated with A12O3,SiO2 and silane coupling agent by chemical liquid deposition.The coating was characterized by Raman spectroscopy,XRD,TEM and FT-IR.The coating content and anti-ultraviolet capacity of nano-TiO2 were measured by XRF and UV-vis spectrometer.The results show that dense coatings containing 5% Al2O3 or SiO2 can be obtained by mixing slurry at pH 10,adding coating reagent and neutralization reagent into the slurry for 60 min at 85?95 ℃,and finally aging for 120 min.Noncrystal SiO2 was coated on the surface of nano-TiO2 to form silica gel polymer with a Ti—O—Si bond,while aluminum compound exists in the form of AlOOH and part Al(OH)3.The integrated dense film can shield photocatalysis effectively.The inorganic coating film can increase the wettability for xylene and stability in water.The surface modification of nano-TiO2 will not impair its ability for anti-ultraviolet radiation,and more short band ultraviolet radiation can be absorbed.In addition,the optimal coating amount of silane coupling agent should be less than 3% and the best wettability for xylene can be reached when the amount is 1.2%.
