AIM： To investigate the apoptotic effect of photoexcited titanium dioxide （TiO2） nanoparticles in the presence of visible light on human hepatoma cell line （Bel 7402） and to study the underlying mechanism. METHOD...AIM： To investigate the apoptotic effect of photoexcited titanium dioxide （TiO2） nanoparticles in the presence of visible light on human hepatoma cell line （Bel 7402） and to study the underlying mechanism. METHODS： Cerium-element-doped titanium dioxide nanoparticles were prepared by impregnation method. Bel 7402 human hepatoma cells were cultured in RPMI 1640 medium in a humidified incubator with 50 mL/L COL at 37℃. A 15 W fluorescent lamp with continuous wavelength light was used as light source in the photocatalytic test. Fluorescence morphology and agarose gel eletrophoresis pattern were performed to analyze apoptotic cells. RESULTS： The Ce （Ⅳ）-doped TiO2 nanoparticles displayed their superiority. The adsorption edge shifted to the 400-450 nm region. With visible light illuminated for 10 min, 10 μg/cm^3 Ce （lV）-doped TiO2 induced micronuclei and significant apoptosis in 4 and 24 h, respectively. Hochest 33 258 staining of the fixed cells revealed typical apoptotic structures （apoptotic bodies）, agarose gel electrophoresis showed typical DNA ladder pattern in treated cells but not in untreated ones. CONCLUSION： Ce （Ⅳ） doped TiO2 nanoparticles can induce apoptosis of Bel 7402 human hepatoma cells in the presence of visible light.展开更多
Electrostatic self-assembly method （ESAM） was used to prepare bentonite supported-nano titanium dioxide photocatalysts. The materials were characterized by X-ray diffraction （XRD）, fourier transform infrared spect...Electrostatic self-assembly method （ESAM） was used to prepare bentonite supported-nano titanium dioxide photocatalysts. The materials were characterized by X-ray diffraction （XRD）, fourier transform infrared spectroscopy （FT-IR） and scanning electron microscopy （SEM）. Methyl orange was used to estimate the photocatalytic activity of the materials. The effects of the calcination temperature and silane dosage on the photocatalytic activity of the samples were investigated. The experimental results show that the bentonite facilitates the formation of anatase and restrains the transformation of anatase to rutile. Part of nano-size TiO2 particles insert into the galleries of bentonite. The photocatalysts exhibit a synergistic effect of adsorption and photocatalysis on methyl orange. Photocatalysts prepared by ESAM method exhibit higher photocatalytic activity and better recycle ability than those of the traditional method.展开更多
New applications and research progress of nano titanium dioxide （TiO2） in coating, environmental protection, chemical industries, cos- metics industry, electronic industrial products, medicine, health and food proce...New applications and research progress of nano titanium dioxide （TiO2） in coating, environmental protection, chemical industries, cos- metics industry, electronic industrial products, medicine, health and food processing fields were summarized in the paper. The results showed that nano TiO2 is the most dynamic one in the new nano material study today, which will have a very important impact on our social economic develop- ment in future. The research and utilization will give people＇s lives enormous changes.展开更多
Prochloraz diluents( 450 ×,475 ×,500 ×) were added with different concentrations of nano-titanium dioxide( Ti O2)( 0. 8%,1. 0%) respectively to prepare complex fresh-keeping agents,which were applied in...Prochloraz diluents( 450 ×,475 ×,500 ×) were added with different concentrations of nano-titanium dioxide( Ti O2)( 0. 8%,1. 0%) respectively to prepare complex fresh-keeping agents,which were applied in the refrigeration of Dioscorea alata Lirm. sp. With rot index,weight loss rate,browning degree( BD),total soluble solids( TSS) content,malondialdehyde( MDA) content,polyphenol oxidase( PPO) activity and peroxidase( POD) activity,DPPH· scavenging rate as evaluation indexes,the preservation effect of the prepared freshkeeping agents on D. alata during the cold storage period was analyzed. The results showed that prochloraz added with nano-titanium dioxide significantly prolonged the storage life,reduced the rot rate and weight loss rate,and slowed the loss of pulp of D. alata. The preservation effect of complex fresh-keeping agent of prochloraz diluent( 475 ×) and nano-titanium dioxide( 1. 0%) was better than that of other treatments.展开更多
Diatomite-based porous ceramics were adopted as carriers to immobilize nano-TiO2 via a hydrolysis-deposition technique. The thermal degradation of as-prepared composites was investigated using thermogravimetric-differ...Diatomite-based porous ceramics were adopted as carriers to immobilize nano-TiO2 via a hydrolysis-deposition technique. The thermal degradation of as-prepared composites was investigated using thermogravimetric-differential thermal analysis, and the phase and microstructure were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and transmission electron microscopy. The results indicated that the carriers were encapsulated by nano-TiO2 with a thickness of 300-450 nm. The main crystalline phase of TiO2 calcined at 650~C was anatase, and the average grain size was 8.3 nm. The FT-IR absorption bands at 955.38 cm1 suggested that new chemical bonds among Ti, O, and Si had formed in the composites. The photocatalytic （PC） activity of the composites was investigated un- der UV irradiation. Furthermore, the photodegradation kinetics of formaldehyde was investigated using the composites as the cores of an air cleaner. A kinetics study showed that the reaction rate constants of the gas-phase PC reaction of formaldehyde were k = 0.576 mg＇m3·min^-1 and K = 0.048 m3/mg.展开更多
A series of europium-doped titanium dioxide (TiO 2) fluorescent nano-material s prepared by sol-gel method is presented. The phase structure and crystalline sizes of TiO 2∶Eu, which is doped with different europiu...A series of europium-doped titanium dioxide (TiO 2) fluorescent nano-material s prepared by sol-gel method is presented. The phase structure and crystalline sizes of TiO 2∶Eu, which is doped with different europium content and then he at-treated at different temperature, were investigated by XRD,TG,DTA and TEM. The results show that europium could be introduced into TiO 2 under high temper ature and it can suppress the structural phase transition from anatase to rutile and the crystal growth of TiO 2 in TiO 2∶Eu nano-materials. The fluorescenc e spectra were examined by fluorescence spectrophotometer, and the results show that the fluorescence intensity is the strongest when europium content is 2.68%( mole fraction) and the heat-treated temperature is 700 ℃. From the measurement results of the fluorescence lifetimes, it can be seen that the fluorescence lifetime c ould be prolonged when europium is incorporated in TiO 2.展开更多
In the present work, composites of poly (methyl methacrylate)/titanium oxide nanoparticles (100/0, 97.5/2.5, 95/5, 92.5/7.5, 90/10 and 0/100 wt/wt%)were prepared to be used as bioequivalent materials according to thei...In the present work, composites of poly (methyl methacrylate)/titanium oxide nanoparticles (100/0, 97.5/2.5, 95/5, 92.5/7.5, 90/10 and 0/100 wt/wt%)were prepared to be used as bioequivalent materials according to their importance broad practical and medical applications. Thermal properties as well as X-ray diffraction analyses were employed to characterize the structure properties of such composite. The obtained results showed variations in the glass transition temperature (Tg), the melting temperature (Tm), shape and area of thermal peaks which were attributed to the different degrees of crystallinity and the existence of interactions between PMMA and TiO2 nanoparticle molecules. The XRD patterns showed sharpening of peaks at different concentrations of nano-TiO2 powder with PMMA. This indicated changes in the crystallinity/amorphosity ratio, and also suggested that the miscibility between the amorphous components of homo- polymers PMMA and nano-TiO2 powder is possible.The results showed that nano-TiO2 powder mix with PMMA can improve the thermal stability of the homo-polymer under investigation, lead- ing to interesting technological applications.展开更多
The two-step nano-scale self-assembly technique and the framework structure mechanism for forming mesoporous supports were employed for preparing Al2O3-TiO2 complex supports with large pore volume that were applied fo...The two-step nano-scale self-assembly technique and the framework structure mechanism for forming mesoporous supports were employed for preparing Al2O3-TiO2 complex supports with large pore volume that were applied for manufacturing the resid hydrotreating catalysts. The influence of different TiO2 contents and calcination temperatures on specific surface area, pore volume and pore size distribution of complex supports was studied. TEM and SEM were employed to characterize the Al2O3-TiO2 complex supports. Test results revealed that the specific surface area of Al2O3-TiO2 complex supports was the largest at a TiO2 mass fraction of 20%, and when the calcination temperature was in the range between 300 ℃ to 700 ℃, the pore distribution of the complex support was stable. Characterization of the complex support by TEM and SEM demonstrated that TiO2 was homo- geneously distributed in the complex support, which was in favor of carrying active components. The Al2O3-TiO2 complex supports can function as the best catalyst support for resid hydrotreating catalysts.展开更多
文摘AIM： To investigate the apoptotic effect of photoexcited titanium dioxide （TiO2） nanoparticles in the presence of visible light on human hepatoma cell line （Bel 7402） and to study the underlying mechanism. METHODS： Cerium-element-doped titanium dioxide nanoparticles were prepared by impregnation method. Bel 7402 human hepatoma cells were cultured in RPMI 1640 medium in a humidified incubator with 50 mL/L COL at 37℃. A 15 W fluorescent lamp with continuous wavelength light was used as light source in the photocatalytic test. Fluorescence morphology and agarose gel eletrophoresis pattern were performed to analyze apoptotic cells. RESULTS： The Ce （Ⅳ）-doped TiO2 nanoparticles displayed their superiority. The adsorption edge shifted to the 400-450 nm region. With visible light illuminated for 10 min, 10 μg/cm^3 Ce （lV）-doped TiO2 induced micronuclei and significant apoptosis in 4 and 24 h, respectively. Hochest 33 258 staining of the fixed cells revealed typical apoptotic structures （apoptotic bodies）, agarose gel electrophoresis showed typical DNA ladder pattern in treated cells but not in untreated ones. CONCLUSION： Ce （Ⅳ） doped TiO2 nanoparticles can induce apoptosis of Bel 7402 human hepatoma cells in the presence of visible light.
基金Funded by the Natural Science Foundation of Hebei Province, China (No. E2008000537)the Foundation for Development of Science and Technology of Hebei Province, China (No. 07215156)the Open Research Foundation of Key Laboratory of Advanced Civil Engineering Materials (Tongji University),Ministry of Education, China (No. 2010412)
文摘Electrostatic self-assembly method （ESAM） was used to prepare bentonite supported-nano titanium dioxide photocatalysts. The materials were characterized by X-ray diffraction （XRD）, fourier transform infrared spectroscopy （FT-IR） and scanning electron microscopy （SEM）. Methyl orange was used to estimate the photocatalytic activity of the materials. The effects of the calcination temperature and silane dosage on the photocatalytic activity of the samples were investigated. The experimental results show that the bentonite facilitates the formation of anatase and restrains the transformation of anatase to rutile. Part of nano-size TiO2 particles insert into the galleries of bentonite. The photocatalysts exhibit a synergistic effect of adsorption and photocatalysis on methyl orange. Photocatalysts prepared by ESAM method exhibit higher photocatalytic activity and better recycle ability than those of the traditional method.
基金Supported by Key Scientific and Technological Program of Henan Province (112102310424)
文摘New applications and research progress of nano titanium dioxide （TiO2） in coating, environmental protection, chemical industries, cos- metics industry, electronic industrial products, medicine, health and food processing fields were summarized in the paper. The results showed that nano TiO2 is the most dynamic one in the new nano material study today, which will have a very important impact on our social economic develop- ment in future. The research and utilization will give people＇s lives enormous changes.
基金Supported by Natural Science Foundation of Guangxi(2017GXNSFAA198082)Guangxi First-class Discipline Cultivation Project for Food Science and Engineering(GXYLXP1812)
文摘Prochloraz diluents( 450 ×,475 ×,500 ×) were added with different concentrations of nano-titanium dioxide( Ti O2)( 0. 8%,1. 0%) respectively to prepare complex fresh-keeping agents,which were applied in the refrigeration of Dioscorea alata Lirm. sp. With rot index,weight loss rate,browning degree( BD),total soluble solids( TSS) content,malondialdehyde( MDA) content,polyphenol oxidase( PPO) activity and peroxidase( POD) activity,DPPH· scavenging rate as evaluation indexes,the preservation effect of the prepared freshkeeping agents on D. alata during the cold storage period was analyzed. The results showed that prochloraz added with nano-titanium dioxide significantly prolonged the storage life,reduced the rot rate and weight loss rate,and slowed the loss of pulp of D. alata. The preservation effect of complex fresh-keeping agent of prochloraz diluent( 475 ×) and nano-titanium dioxide( 1. 0%) was better than that of other treatments.
基金financially supported by the National Natural Science Foundation of China (No. 50708037)the National Science Fund for Excellent Young Scholars of China (No. 51522402)+1 种基金the Science and Technology Research Projects in Zhengzhou (No. 141PPTGG388)the National Innovation and Entrepreneurship Training Program of the Undergraduate (No. 201610078034)
文摘Diatomite-based porous ceramics were adopted as carriers to immobilize nano-TiO2 via a hydrolysis-deposition technique. The thermal degradation of as-prepared composites was investigated using thermogravimetric-differential thermal analysis, and the phase and microstructure were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and transmission electron microscopy. The results indicated that the carriers were encapsulated by nano-TiO2 with a thickness of 300-450 nm. The main crystalline phase of TiO2 calcined at 650~C was anatase, and the average grain size was 8.3 nm. The FT-IR absorption bands at 955.38 cm1 suggested that new chemical bonds among Ti, O, and Si had formed in the composites. The photocatalytic （PC） activity of the composites was investigated un- der UV irradiation. Furthermore, the photodegradation kinetics of formaldehyde was investigated using the composites as the cores of an air cleaner. A kinetics study showed that the reaction rate constants of the gas-phase PC reaction of formaldehyde were k = 0.576 mg＇m3·min^-1 and K = 0.048 m3/mg.
文摘A series of europium-doped titanium dioxide (TiO 2) fluorescent nano-material s prepared by sol-gel method is presented. The phase structure and crystalline sizes of TiO 2∶Eu, which is doped with different europium content and then he at-treated at different temperature, were investigated by XRD,TG,DTA and TEM. The results show that europium could be introduced into TiO 2 under high temper ature and it can suppress the structural phase transition from anatase to rutile and the crystal growth of TiO 2 in TiO 2∶Eu nano-materials. The fluorescenc e spectra were examined by fluorescence spectrophotometer, and the results show that the fluorescence intensity is the strongest when europium content is 2.68%( mole fraction) and the heat-treated temperature is 700 ℃. From the measurement results of the fluorescence lifetimes, it can be seen that the fluorescence lifetime c ould be prolonged when europium is incorporated in TiO 2.
文摘In the present work, composites of poly (methyl methacrylate)/titanium oxide nanoparticles (100/0, 97.5/2.5, 95/5, 92.5/7.5, 90/10 and 0/100 wt/wt%)were prepared to be used as bioequivalent materials according to their importance broad practical and medical applications. Thermal properties as well as X-ray diffraction analyses were employed to characterize the structure properties of such composite. The obtained results showed variations in the glass transition temperature (Tg), the melting temperature (Tm), shape and area of thermal peaks which were attributed to the different degrees of crystallinity and the existence of interactions between PMMA and TiO2 nanoparticle molecules. The XRD patterns showed sharpening of peaks at different concentrations of nano-TiO2 powder with PMMA. This indicated changes in the crystallinity/amorphosity ratio, and also suggested that the miscibility between the amorphous components of homo- polymers PMMA and nano-TiO2 powder is possible.The results showed that nano-TiO2 powder mix with PMMA can improve the thermal stability of the homo-polymer under investigation, lead- ing to interesting technological applications.
文摘The two-step nano-scale self-assembly technique and the framework structure mechanism for forming mesoporous supports were employed for preparing Al2O3-TiO2 complex supports with large pore volume that were applied for manufacturing the resid hydrotreating catalysts. The influence of different TiO2 contents and calcination temperatures on specific surface area, pore volume and pore size distribution of complex supports was studied. TEM and SEM were employed to characterize the Al2O3-TiO2 complex supports. Test results revealed that the specific surface area of Al2O3-TiO2 complex supports was the largest at a TiO2 mass fraction of 20%, and when the calcination temperature was in the range between 300 ℃ to 700 ℃, the pore distribution of the complex support was stable. Characterization of the complex support by TEM and SEM demonstrated that TiO2 was homo- geneously distributed in the complex support, which was in favor of carrying active components. The Al2O3-TiO2 complex supports can function as the best catalyst support for resid hydrotreating catalysts.
