Oleic acid （denoted as OA） surface-capped lanthanum-doped titanium dioxide composite nanoparticles, abbreviated as OA/La-TiO2, were prepared via sol-gel method in association with surface modification by oleic acid....Oleic acid （denoted as OA） surface-capped lanthanum-doped titanium dioxide composite nanoparticles, abbreviated as OA/La-TiO2, were prepared via sol-gel method in association with surface modification by oleic acid. The microstructure of as-prepared OA/La-TiO2 was characterized by means of X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectrometry, and their thermal stability was evaluated by thermogravimetry and differential scanning calorimetry. Moreover, the tribological properties of OA/La-TiO2 as lubricant additives in rapeseed oil were evaluated with a four-ball friction and wear tester. The morphology as well as elemental composition and chemical characteristics of worn steel surfaces was investigated by scanning electron microscopy, energy dispersive X-ray spectrometry and X-ray photoelectron spectroscopy. Results showed that as-prepared OA/La-TiO2 particles were of spherical shape and had an average diameter of 20 nm. In the meantime, OA/La-TiO2 particles doped with 1.5% （molar ratio; the same hereafter） and 2.5% of lanthanum could markedly improve the anti-wear and friction-reducing capacities of rapeseed oil. This is attributed to the formation of a complex boundary lubrication film mainly composed of the oxides of iron, titanium and lanthanum as well as the formation of an adsorption film of oleic acid on steel sliding surfaces.展开更多
Crystalline TiO2 nanoparticles were synthesized by hydrolysis of titanium tetrabutoxide in the presence of hydrochloric acid in NP-5 (Igepal CO-520)/ cyclohexane reverse micelle solution at room temperature. Pure rut...Crystalline TiO2 nanoparticles were synthesized by hydrolysis of titanium tetrabutoxide in the presence of hydrochloric acid in NP-5 (Igepal CO-520)/ cyclohexane reverse micelle solution at room temperature. Pure rutile nanoparticles were obtained at an appropriate acid concentration. The influences of various reaction conditions such as the concentration of acids, water content value (w=[H2O]/[NP-5]) on the formation, crystal phase, morphology, and size of the TiO2 particles were investigated.展开更多
It is reported thut nanoporticles can be applied as carriers and anti-cancer medicines. But the interaction of nanoparticles and cells is unclear. The purpose of this study was to discuss whether inorganic crystal nan...It is reported thut nanoporticles can be applied as carriers and anti-cancer medicines. But the interaction of nanoparticles and cells is unclear. The purpose of this study was to discuss whether inorganic crystal nanoparticles can get through cells with intact crystal. BEL7402 heputoma cells and titanium dioxide （ TiO2 ） nanoporticles were selected and incubated together in vitro. All specimens were prepared and observed under a traasmission electron mieroscope （TEM）. TiO2 nanopartieles were found not in the nuclear area but in the cytoplasma. TiO2 nanoponieles maintained the plate-like shape during absorbing. The result shows that hepatoma cells can endocytose the intact TiO2 crystal nanoparticles. It implies that novel nano-effect plays an important role in the biomedicinal application of inorganic crystal nanopartieles.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 present work aims to ascertain the mechanisms of surfactant（dodecylbenzene sulfonate; DBS） effects on the aggregation behaviors of TiO2 nanoparticles（TiO2-NPs） in natural water samples. Aggregation experiments...The present work aims to ascertain the mechanisms of surfactant（dodecylbenzene sulfonate; DBS） effects on the aggregation behaviors of TiO2 nanoparticles（TiO2-NPs） in natural water samples. Aggregation experiments were conducted at a TiO2-NPs concentration of 10 mg/L in deionized water and in natural water samples via dynamic light scattering and Zeta potential determination. Average attachment efficiency was calculated to compare the aggregation behaviors of nanoparticles in the two aqueous media. Results showed that the effects of DBS on aggregation could be interpreted by both Derjaguin–Landau–Verwey–Overbeek（DLVO） and non-DLVO mechanisms. In natural water samples,aggregation did not occur rapidly and was able to develop slowly under all conditions, and the roles of DBS were obvious at high DBS concentration owing to the impacts of inherent components of natural water samples, such as colloids and natural organic compounds.Future aggregation studies should concentrate on multi-factor, multi-colloidal and dynamic aspects under similar environmental conditions.展开更多
基金supported by National Natural Science Foundation of China(50975282)
文摘Oleic acid （denoted as OA） surface-capped lanthanum-doped titanium dioxide composite nanoparticles, abbreviated as OA/La-TiO2, were prepared via sol-gel method in association with surface modification by oleic acid. The microstructure of as-prepared OA/La-TiO2 was characterized by means of X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectrometry, and their thermal stability was evaluated by thermogravimetry and differential scanning calorimetry. Moreover, the tribological properties of OA/La-TiO2 as lubricant additives in rapeseed oil were evaluated with a four-ball friction and wear tester. The morphology as well as elemental composition and chemical characteristics of worn steel surfaces was investigated by scanning electron microscopy, energy dispersive X-ray spectrometry and X-ray photoelectron spectroscopy. Results showed that as-prepared OA/La-TiO2 particles were of spherical shape and had an average diameter of 20 nm. In the meantime, OA/La-TiO2 particles doped with 1.5% （molar ratio; the same hereafter） and 2.5% of lanthanum could markedly improve the anti-wear and friction-reducing capacities of rapeseed oil. This is attributed to the formation of a complex boundary lubrication film mainly composed of the oxides of iron, titanium and lanthanum as well as the formation of an adsorption film of oleic acid on steel sliding surfaces.
基金Support from the National Natural Science Foundation of China (20003001) the Special Fund of MEC (200020) and the Doctoral Program Foundation of MEC (2000000155) is gratefully acknowledged.
文摘Crystalline TiO2 nanoparticles were synthesized by hydrolysis of titanium tetrabutoxide in the presence of hydrochloric acid in NP-5 (Igepal CO-520)/ cyclohexane reverse micelle solution at room temperature. Pure rutile nanoparticles were obtained at an appropriate acid concentration. The influences of various reaction conditions such as the concentration of acids, water content value (w=[H2O]/[NP-5]) on the formation, crystal phase, morphology, and size of the TiO2 particles were investigated.
文摘It is reported thut nanoporticles can be applied as carriers and anti-cancer medicines. But the interaction of nanoparticles and cells is unclear. The purpose of this study was to discuss whether inorganic crystal nanoparticles can get through cells with intact crystal. BEL7402 heputoma cells and titanium dioxide （ TiO2 ） nanoporticles were selected and incubated together in vitro. All specimens were prepared and observed under a traasmission electron mieroscope （TEM）. TiO2 nanopartieles were found not in the nuclear area but in the cytoplasma. TiO2 nanoponieles maintained the plate-like shape during absorbing. The result shows that hepatoma cells can endocytose the intact TiO2 crystal nanoparticles. It implies that novel nano-effect plays an important role in the biomedicinal application of inorganic crystal nanopartieles.
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.
基金supported by the State Key Laboratory of Urban Water Resource and Environment(No.2014DX06)the National Natural Science Foundation of China(No.51208142)
文摘The present work aims to ascertain the mechanisms of surfactant（dodecylbenzene sulfonate; DBS） effects on the aggregation behaviors of TiO2 nanoparticles（TiO2-NPs） in natural water samples. Aggregation experiments were conducted at a TiO2-NPs concentration of 10 mg/L in deionized water and in natural water samples via dynamic light scattering and Zeta potential determination. Average attachment efficiency was calculated to compare the aggregation behaviors of nanoparticles in the two aqueous media. Results showed that the effects of DBS on aggregation could be interpreted by both Derjaguin–Landau–Verwey–Overbeek（DLVO） and non-DLVO mechanisms. In natural water samples,aggregation did not occur rapidly and was able to develop slowly under all conditions, and the roles of DBS were obvious at high DBS concentration owing to the impacts of inherent components of natural water samples, such as colloids and natural organic compounds.Future aggregation studies should concentrate on multi-factor, multi-colloidal and dynamic aspects under similar environmental conditions.
