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
The dispersion state of nano-TiO2 particles was studied by using transmission electron microscopy （TEM）and Fourier transform infrared spectroscopy （FT-IR）. Nanoparticles can be fully dispersed by specific hyperdis...The dispersion state of nano-TiO2 particles was studied by using transmission electron microscopy （TEM）and Fourier transform infrared spectroscopy （FT-IR）. Nanoparticles can be fully dispersed by specific hyperdispersant. The improvement of nano-TiO2 in thermal behavior and flame retardation of acrylic polymer and fire-resistant coating was investigated by differential thermal analysis （DTA）, thermogravimetry （TG）and fire-resistant time test. It is demonstrated that nano-TiO2 is helpful for enhancing the thermal stability,anti-oxidation and fire-resistant properties of acrylic polymer and fire-resistant coating.展开更多
A novel technology of in-situ coating Al2O3 on the surface of H4TiO4 was developed to prevent the aggregation of nano-TiO2 powders and improve the dispersibility and thermal stability in the way of forming a uniform c...A novel technology of in-situ coating Al2O3 on the surface of H4TiO4 was developed to prevent the aggregation of nano-TiO2 powders and improve the dispersibility and thermal stability in the way of forming a uniform coating layer. The heterogeneous nucleation was conducted to prepare the precursor of nano-TiO2 and then Al2O3 was coated on the surface of precursor. The effects of Al2O3 in-situ coating on the properties of nano-TiO2 were investigated. The results show that H4 TiO4 can be dispersed well under alkaline condition （pH 8. 5） and the heterogeneous nucleation can be controlled easily. The optimized uniform coating layer is obtained by adding 5 % （mass fraction ） and 10% of Al2O3 and the aggregation of nano-TiO2 powders is effectively inhibited and the dispersibility is obviously improved. The crystal sizes of TiO2 powders are 12.3, 11.4 and 8. 7 nm after coating 0, 5% and 10% of Al2O3 respectively. Al2O3 on the surface of particulates in amorphous phase could increase the thermal stability of nano-partieles after calcined at 550℃.展开更多
Alkyd coatings embedded with nano-TiO2 and nano-ZnO pigments were prepared. The effects of nano pigments on anticorrosion performance of alkyd coatings were investigated using electrochemical impedance spectrum （EIS...Alkyd coatings embedded with nano-TiO2 and nano-ZnO pigments were prepared. The effects of nano pigments on anticorrosion performance of alkyd coatings were investigated using electrochemical impedance spectrum （EIS）. For the sake of comparison, the corrosion protection of alkyd coatings with conventional TiO2 and ZnO was also studied. It was found that nano-TiO2 pigment improved the corrosion resistance as well as the hardness of alkyd coatings. The optimal amount of nano-TiO2 in a colored coating for corrosion resistance was 1%. The viscosities of alkyd coatings with nanometer TiO2 and ZnO and conventional TiO2 and ZnO pigments were measured and the relation between viscosity and anticorrosion performance was discussed.展开更多
[Objective] This study aimed to investigate the antibacterial and preservation effects of silver-doped nano-TiO2 on Nanfeng citrus. [Method] Silverdoped nano-TiO2 preservative film was prepared, to investigate its pre...[Objective] This study aimed to investigate the antibacterial and preservation effects of silver-doped nano-TiO2 on Nanfeng citrus. [Method] Silverdoped nano-TiO2 preservative film was prepared, to investigate its preservation effects on Nanfeng citrus ripe fruits under novel preservation conditions and detect the influences of nano-composite coating on physiological quality indicators of Nanfeng citrus ripe fruits. [ Result ] Compared with the control, applying nano-compesite coating preservation technology could prevent fruit corruption and water loss and delay the rapid reductioh in contents of citric acid and Vc, without adverse influences on fruit quality. [ Conclusion] Silver-doped nano-TiO2 composite coating can be promoted and applied in frozen storage and preservation practices of Nanfeng citrus.展开更多
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%.
文摘The dispersion state of nano-TiO2 particles was studied by using transmission electron microscopy （TEM）and Fourier transform infrared spectroscopy （FT-IR）. Nanoparticles can be fully dispersed by specific hyperdispersant. The improvement of nano-TiO2 in thermal behavior and flame retardation of acrylic polymer and fire-resistant coating was investigated by differential thermal analysis （DTA）, thermogravimetry （TG）and fire-resistant time test. It is demonstrated that nano-TiO2 is helpful for enhancing the thermal stability,anti-oxidation and fire-resistant properties of acrylic polymer and fire-resistant coating.
文摘A novel technology of in-situ coating Al2O3 on the surface of H4TiO4 was developed to prevent the aggregation of nano-TiO2 powders and improve the dispersibility and thermal stability in the way of forming a uniform coating layer. The heterogeneous nucleation was conducted to prepare the precursor of nano-TiO2 and then Al2O3 was coated on the surface of precursor. The effects of Al2O3 in-situ coating on the properties of nano-TiO2 were investigated. The results show that H4 TiO4 can be dispersed well under alkaline condition （pH 8. 5） and the heterogeneous nucleation can be controlled easily. The optimized uniform coating layer is obtained by adding 5 % （mass fraction ） and 10% of Al2O3 and the aggregation of nano-TiO2 powders is effectively inhibited and the dispersibility is obviously improved. The crystal sizes of TiO2 powders are 12.3, 11.4 and 8. 7 nm after coating 0, 5% and 10% of Al2O3 respectively. Al2O3 on the surface of particulates in amorphous phase could increase the thermal stability of nano-partieles after calcined at 550℃.
基金the financial support from the National Natural Science Foundation of China(No.50499334).
文摘Alkyd coatings embedded with nano-TiO2 and nano-ZnO pigments were prepared. The effects of nano pigments on anticorrosion performance of alkyd coatings were investigated using electrochemical impedance spectrum （EIS）. For the sake of comparison, the corrosion protection of alkyd coatings with conventional TiO2 and ZnO was also studied. It was found that nano-TiO2 pigment improved the corrosion resistance as well as the hardness of alkyd coatings. The optimal amount of nano-TiO2 in a colored coating for corrosion resistance was 1%. The viscosities of alkyd coatings with nanometer TiO2 and ZnO and conventional TiO2 and ZnO pigments were measured and the relation between viscosity and anticorrosion performance was discussed.
文摘[Objective] This study aimed to investigate the antibacterial and preservation effects of silver-doped nano-TiO2 on Nanfeng citrus. [Method] Silverdoped nano-TiO2 preservative film was prepared, to investigate its preservation effects on Nanfeng citrus ripe fruits under novel preservation conditions and detect the influences of nano-composite coating on physiological quality indicators of Nanfeng citrus ripe fruits. [ Result ] Compared with the control, applying nano-compesite coating preservation technology could prevent fruit corruption and water loss and delay the rapid reductioh in contents of citric acid and Vc, without adverse influences on fruit quality. [ Conclusion] Silver-doped nano-TiO2 composite coating can be promoted and applied in frozen storage and preservation practices of Nanfeng citrus.
