Magnetically recyclable porous sodium dodecyl sulfate(SDS)/Fe2O3 hybrids,which combine the porous structure of Fe2O3 and hydrophobicity of SDS,have been successfully synthesized for the first time.Porous Fe2O3 has bee...Magnetically recyclable porous sodium dodecyl sulfate(SDS)/Fe2O3 hybrids,which combine the porous structure of Fe2O3 and hydrophobicity of SDS,have been successfully synthesized for the first time.Porous Fe2O3 has been first pyrolyzed from MIL-100(Fe)using a simple two-step calcination route.Then,the obtained porous Fe2O3 nanoparticles have been self-assembled with SDS molecules and yielded hydrophobic SDS/Fe2O3 hybrids.The porous SDS/Fe2O3 hybrids have been demonstrated to be highly efficient for the denitrification of pyridine under visible light irradiation.The pyridine removal ratio has reached values as high as 100%after irradiation for 240 min.Combining the results of a series of experimental measurements,it was concluded that the superior photocatalytic performance of SDS/Fe2O3 hybrids could be attributed to(i)the fast electron transport owing to the unique porous structure of Fe2O3,(ii)the superior visible light absorption of Fe2O3 nanoparticles,and(iii)the“bridge molecule”role of SDS efficiently improving the separation and transfer across the interfacial domain of SDS/Fe2O3 of photogenerated electron-hole pairs.More significantly,after the catalytic reaction,the SDS/Fe2O3 hybrids could be easily recovered using magnets and reused during subsequent cycles,which indicated their stability and recyclability.展开更多
Mesoporous superacids S2O82–-Fe2O3/SBA-15(SFS)with active nanoparticles are prepared by ultrasonic adsorption method.This method is adopted to ensure a homo-dispersed nanoparticle active phase,large specific surface ...Mesoporous superacids S2O82–-Fe2O3/SBA-15(SFS)with active nanoparticles are prepared by ultrasonic adsorption method.This method is adopted to ensure a homo-dispersed nanoparticle active phase,large specific surface area and many acidic sites.Compared with bulk S2O82–-Fe2O3,Br?nsted acid catalysts and other reported catalysts,SFS with an Fe2O3 loading of 30%(SFS-30)exhibits an outstanding activity in the probe reaction of alcoholysis of styrene oxide by methanol with 100%yield.Moreover,SFS-30 also shows a more excellent catalytic performance than bulk S2O82–-Fe2O3 towards the alcoholysis of other ROHs(R=C2H5-C4H9).Lewis and Bronsted acid sites on the SFS-30 surfaces are confirmed by pyridine adsorbed infrared spectra.The highly efficient catalytic activity of SFS-30 may be attributed to the synergistic effect from the nano-effect of S2O82–-Fe2O3 nanoparticles and the mesostructure of SBA-15.Finally,SFS-30 shows a good catalytic reusability,providing an 84.1%yield after seven catalytic cycles.展开更多
Fe3O4 magnetic nanoparticles(MNPs) were synthesised, characterised, and used as a peroxidase mimetic to accelerate levofloxacin sono-degradation in an ultrasound(US)/H2O2 system. The Fe3O4 MNPs were in nanometre scale...Fe3O4 magnetic nanoparticles(MNPs) were synthesised, characterised, and used as a peroxidase mimetic to accelerate levofloxacin sono-degradation in an ultrasound(US)/H2O2 system. The Fe3O4 MNPs were in nanometre scale with an average diameter of approximately 12 to 18 nm. The introduction of Fe3O4 MNPs increased levofloxacin sono-degradation in the US/H2O2 system. Experimental parameters, such as Fe3O4 MNP dose, initial solution p H, and H2O2 concentration, were investigated by a one-factor-at-a-time approach. The results showed that Fe3O4 MNPs enhanced levofloxacin removal in the p H range from 4.0 to 9.0. Levofloxacin removal ratio increased with Fe3O4 MNP dose up to 1.0 g·L-1and with H2O2 concentration until reaching the maximum. Moreover, three main intermediate compounds were identified by HPLC with electrospray ionisation tandem mass spectrometry, and a possible degradation pathway was proposed. This study suggests that combination of H2O2, Fe3O4 MNPs and US is a good way to improve the degradation efficiency of antibiotics.展开更多
In recent decades, many additives with different characteristics have been applied to strengthen and toughen Al2O3-based ceramic cutting tool materials. Among them, SiC whiskers and SiC nanoparticles showed excellent ...In recent decades, many additives with different characteristics have been applied to strengthen and toughen Al2O3-based ceramic cutting tool materials. Among them, SiC whiskers and SiC nanoparticles showed excellent performance in improving the material properties. While no attempts have been made to add SiC whiskers and SiC nanoparticles together into the ceramic matrix and the synergistically toughening effects of them have not been studied. An Al2O3-SiCw-SiC np advanced ceramic cutting tool material is fabricated by adding both one-dimensional SiC whiskers and zero-dimensional SiC nanoparticles into the Al2O3 matrix with an effective dispersing and mixing process. The composites with 25 vol% SiC whiskers and 25 vol% SiC nanoparticles alone are also investegated for comparison purposes. Results show that the Al2O3-SiCw-SiCnp composite with both 20 vo1% SiC whiskers and 5 vol% SiC nanoparticles additives have much improved mechanical properties. The flexural strength of Al2O3-SiCw-SiCnp is 730＋ 95 MPa and fracture toughness is 5.6 ± 0.6 MPa.m1/2. The toughening and strengthening mechanisms of SiC whiskers and nanoparticles are studied when they are added either individually or in combination. It is indicated that when SiC whiskers and nanoparticles are added together, the grains are further refined and homogenized, so that the microstructure and fracture mode ratio is modified. The SiC nanoparticles are found helpful to enhance the toughening effects of the SiC whiskers. The proposed research helps to enrich the types of ceramic cutting tool and is benefit to expand the application range of ceramic cutting tool.展开更多
The Fe3O4@SiO2 composite nanoparticles were obtained from as-synthesized magnetite (Fe3O4) nanoparticles through the modified St?ber method. Then, the Fe3O4 nanoparticles and Fe3O4@SiO2 composite nanoparticles were ch...The Fe3O4@SiO2 composite nanoparticles were obtained from as-synthesized magnetite (Fe3O4) nanoparticles through the modified St?ber method. Then, the Fe3O4 nanoparticles and Fe3O4@SiO2 composite nanoparticles were characterized by means of X-ray diffraction (XRD), Raman spectra, scanning electron microscope (SEM) and vibrating sample magnetometer (VSM). Recently, the studies focus on how to improve the dispersion of composite particle and achieve good magnetic performance. Hence effects of the volume ratio of tetraethyl orthosilicate (TEOS) and magnetite colloid on the structural, morphological and magnetic properties of the composite nanoparticles were systematically investi-gated. The results revealed that the Fe3O4@SiO2 had better thermal stability and dispersion than the magnetite nanoparticles. Furthermore, the particle size and magnetic property of the Fe3O4@SiO2 composite nanoparticles can be adjusted by changing the volume ratio of TEOS and magnetite colloid.展开更多
The film forming behavior on the interface between air and hydrosol of Fe2O3 nanoparticles was investigated by the surface pressure-time isotherms, the surface pressure-trough area isotherms, Brewster angle microscopy...The film forming behavior on the interface between air and hydrosol of Fe2O3 nanoparticles was investigated by the surface pressure-time isotherms, the surface pressure-trough area isotherms, Brewster angle microscopy and transmission electron microscopy. It is found that the freshly prepared hydrosol of Fe2O3 nanoparticles is not stable. The surface pressure increases with the aging time and finally approaches a constant, and the smaller the concentration is, the smaller the surface pressure is stabilized at and the shorter the time the hydrosol reaching stable needs. The surface pressure also increases with compression until collapsed, and the longer the hydrosol is aged, the higher the collapsing pressure is. A uniform and compact film composed of nanoparticles with an average diameter of about 2-3 nm on the air-hydrosol interface is observed by Brewster angle microscope and transmission electron microscope.展开更多
In order to modify inorganic particles as chromatic electrophoretic particles, an approach was designed and used to prepare Fe203 red electrophoretic particles. These Fe203-cationic hybrid nanoparticles （Fe203-CHNPs...In order to modify inorganic particles as chromatic electrophoretic particles, an approach was designed and used to prepare Fe203 red electrophoretic particles. These Fe203-cationic hybrid nanoparticles （Fe203-CHNPs）were prepared through Fe203 core covered with polymer shell which was composed of SiO2 and P （DMAEMA-co-HMA） by using atom transfer radical polymerization （ATRP）technique. The SiO：-coating could introduce the functional group on the surfaceof inorganic particles, through which the polymer shell could be formed by using ATRP tech- nique. The results of Fourier transform infrared spectra （FT-IR）, X-ray photoelectron spectroscopy （XPS） and thermal gravimetric analysis （TGA）confirmed the chemical compositions of Fe2O3-CHNPs; the images of transmission elec- tron microscopy （TEM） indicated the core-shell structure of Fe2O3-CHNPs; the measurements of dynamic light scatter- ing （DLS） showed a 253.7 nm average particle size with narrow size distribution; and the zeta potential measurements identified the high chargeability of Fe2O3-CHNPs. Furthermore, the resulting nanoparticles were successfully applied in the electrophoretic display cell, which demonstrated that it was an effective approach to preparing chromatic elec- trophoretic particles.展开更多
The properties of La 2O 3 doped molybdenum powder were studied. The La 2O 3 nanoparticles on the surface of molybdenum powder which is produced by the reduction of La(NO 3) 3 doped MoO 2 in hydrogen decrease the inten...The properties of La 2O 3 doped molybdenum powder were studied. The La 2O 3 nanoparticles on the surface of molybdenum powder which is produced by the reduction of La(NO 3) 3 doped MoO 2 in hydrogen decrease the intensity of feature energy loss peak of molybdenum substrate; but increase that of peak of Mo?3d. The surface of molybdenum powder exposed to the atmosphere can be reduced because the surface is mainly covered with La 2O 3 nanoparticles. As a result, the capability of anti oxidation of molybdenum is improved.展开更多
Highly biocompatible superparamagnetic Fe3O4 nanoparticles were synthesized by amide of folic acid （FA） ligands and the NH2-group onto the surface of Fe3O4 nanoparticles. The as-synthesized folate-conjugated Fe3O4 n...Highly biocompatible superparamagnetic Fe3O4 nanoparticles were synthesized by amide of folic acid （FA） ligands and the NH2-group onto the surface of Fe3O4 nanoparticles. The as-synthesized folate-conjugated Fe3O4 nanoparticles were characterized by X-ray diffraction diffractometer, transmission electron microscope, FT-IR spectrometer, vibrating sample magnetometer, and dynamic light scattering instrument. The in vivo labeling effect of folate-conjugated Fe3O4 nanoparticles on the hepatoma cells was investigated in tumor-bearing rat. The results demonstrate that the as-prepared nanoparticles have cubic structure of Fe3O4 with a particle size of about 8 nm and hydrated diameter of 25.7 nm at a saturation magnetization of 51 A·m2/kg. These nanoparticles possess good physiological stability, low cytotoxicity on human skin fibroblasts and negligible effect on Wistar rats at the concentration as high as 3 mg/kg body mass. The folate-conjugated Fe3O4 nanoparticles could be effectively mediated into the human hepatoma Bel 7402 cells through the binding of folate and folic acid receptor, enhancing the signal contrast of tumor tissue and surrounding normal tissue in MRI imaging. It is in favor of the tumor cells labeling, tracing, magnetic resonance imaging （MRI） target detection and magnetic hyperthermia.展开更多
Precursor foam based Co incorporated α-Fe<sub>2</sub>O<sub>3</sub> (AFC) was successfully synthesized at 600℃ calcination temperature by simple solution method using PVA. The formation of α-...Precursor foam based Co incorporated α-Fe<sub>2</sub>O<sub>3</sub> (AFC) was successfully synthesized at 600℃ calcination temperature by simple solution method using PVA. The formation of α-Fe<sub>2</sub>O<sub>3</sub> nanoparticles was confirmed by X-ray diffraction measurement and reduction in crystallite size was found after cobalt incorporation. Field emission scanning electron microscopy revealed the existence of pyramidal shaped iron oxide in AFC. FTIR and Raman spectra also confirmed the presence of α-Fe<sub>2</sub>O<sub>3</sub>. Photocatalytic activity study showed that the cobalt incorporated α-Fe<sub>2</sub>O<sub>3</sub> was better photocatalyst than pure α-Fe<sub>2</sub>O<sub>3</sub>. The cobalt incorporated iron oxide nanoparticles could be used for drug delivery application and this simple preparation method could be adopted for the synthesis of other transition metal oxides.展开更多
Objective：To evaluate the in vitro and in vivo toxicity of self-prepared nanosized Fe2O3, which has the potential implication in tumor hyperthermia. Methods： Fe2O3 nanoparticles were prepared by improving co-precipi...Objective：To evaluate the in vitro and in vivo toxicity of self-prepared nanosized Fe2O3, which has the potential implication in tumor hyperthermia. Methods： Fe2O3 nanoparticles were prepared by improving co-precipitation, which characterization was detected by TEM, XRD, CMIAS, EDS. MTT assay was used to evaluate the in vitro cytotoxicity test; hemolytic test was carried out to estimate whether it has blood toxicity; Fe2O3 suspended in sterile 0.9% NaCl was intraperitoneally injected into Kumning mouse to calculate the LD50 ; micronucleus （MN） were reckoned to identify whether it is genotoxic. Results：The nanoparticles are brown spherical particles with diameter ranging from 8 to 15 nm, which have good decentralization and stability. The experiments also showed that the toxicity of the material on mouse fibroblast （L-929） cell lines was 0 - 1 degree ; it has no hemolysis activity; LD50 arrived at 5.45 g/kg^-1 after intraperitoneal injection of 1 ml suspension; micronucleus test showed that it has no genotoxic effects either. Conclusion： The results showed that the Fe2O3 nanoparticles are prepared successfully, the self-prepared nanosized Fe2O3 is a kind of high biocompatibility materials and perhaps it is suitable for further application in tumor hyperthermia.展开更多
Peroxidase-like catalytic properties of Fe3O4 nanoparficles （NPs） with three different sizes, synthesized by chemical coprecipitation and sol-gel methods, were investigated by UV-vis spectrum analysis. By comparing ...Peroxidase-like catalytic properties of Fe3O4 nanoparficles （NPs） with three different sizes, synthesized by chemical coprecipitation and sol-gel methods, were investigated by UV-vis spectrum analysis. By comparing Fe3O4 NPs with average diameters of 11, 20, and 150 nm, we found that the catalytic activity increases with the reduced nanoparticle size. The electrochemical method to characterize the catalytic activity of Fe3O4 NPs using the response currents of the reaction product and substrate was also developed.展开更多
Fe3O4 nanoparticles were prepared by chemistry co-precipitation and the mean crystal size was 17.9 nm measured by XRD. After it had been treated by silane-coupling agents KH570, magnetic micro-spheres dispersed in org...Fe3O4 nanoparticles were prepared by chemistry co-precipitation and the mean crystal size was 17.9 nm measured by XRD. After it had been treated by silane-coupling agents KH570, magnetic micro-spheres dispersed in organic medium glycol were gained and the mean size of Fe3O4 nanopowders was 33.7 nm. So it can be concluded that magnetic micro-sphere is made of a few Fe3O4 crystals. Many factors of modification were researched, such as the time of ball milling, the content of Fe3O4 and the content of KH570. The modification of Fe3O4 is relative to the time of ball milling, but the dominant function is affected by the content of Fe3O4 and KH570. When the content of Fe3O4 is known, there is a suitable content of KH570. Different content of Fe3O4 will make the different suitable content of KH570, but the range of latter is less than former, which is relative to the distribution of KH570 on Fe3O4 surface or in the solution.展开更多
Y2O3： Er^3＋, Yb^3＋ nanoparticles were synthesized by a homogeneous precipitation method without and with different concentrations of EDTA 2Na. Upconversion luminescence spectra of the samples were studied under 980...Y2O3： Er^3＋, Yb^3＋ nanoparticles were synthesized by a homogeneous precipitation method without and with different concentrations of EDTA 2Na. Upconversion luminescence spectra of the samples were studied under 980 nm laser excitation. The results of XRD showed that the obtained Y2O3：Er^3＋,Yb^3＋ nanoparticles were of a cubic structure. The average crystallite sizes calculated were in the range of 28-40 nm. Green and red upconversion emission were observed, and attributed to ^2H11/2,^4S3/2→^4I15/2 and ^4F9/2→^4I15/2 transitions of the ion, respectively. The ratio of the intensity of green emission to that of red emission drastically changed with a change in the EDTA 2Na concentration. In the sample synthesized without EDTA, the relative intensity of the green emission was weaker than that of the red emission. The relative intensities of green emission increased with the increased amount of EDTA 2Na used. The possible upconversion luminescence mechanisms were discussed.展开更多
基金supported by the National Natural Science Foundation of China(21603112,21806085)Natural Science Foundation of Fujian Province(2016J02692,2019J01837)+1 种基金Natural Science Foundation of Ningde Normal University(2018T03,2018Z02)the Program of Innovative Research Team in Science and Technology in Fujian Province University(IRTSTFJ)~~
文摘Magnetically recyclable porous sodium dodecyl sulfate(SDS)/Fe2O3 hybrids,which combine the porous structure of Fe2O3 and hydrophobicity of SDS,have been successfully synthesized for the first time.Porous Fe2O3 has been first pyrolyzed from MIL-100(Fe)using a simple two-step calcination route.Then,the obtained porous Fe2O3 nanoparticles have been self-assembled with SDS molecules and yielded hydrophobic SDS/Fe2O3 hybrids.The porous SDS/Fe2O3 hybrids have been demonstrated to be highly efficient for the denitrification of pyridine under visible light irradiation.The pyridine removal ratio has reached values as high as 100%after irradiation for 240 min.Combining the results of a series of experimental measurements,it was concluded that the superior photocatalytic performance of SDS/Fe2O3 hybrids could be attributed to(i)the fast electron transport owing to the unique porous structure of Fe2O3,(ii)the superior visible light absorption of Fe2O3 nanoparticles,and(iii)the“bridge molecule”role of SDS efficiently improving the separation and transfer across the interfacial domain of SDS/Fe2O3 of photogenerated electron-hole pairs.More significantly,after the catalytic reaction,the SDS/Fe2O3 hybrids could be easily recovered using magnets and reused during subsequent cycles,which indicated their stability and recyclability.
文摘Mesoporous superacids S2O82–-Fe2O3/SBA-15(SFS)with active nanoparticles are prepared by ultrasonic adsorption method.This method is adopted to ensure a homo-dispersed nanoparticle active phase,large specific surface area and many acidic sites.Compared with bulk S2O82–-Fe2O3,Br?nsted acid catalysts and other reported catalysts,SFS with an Fe2O3 loading of 30%(SFS-30)exhibits an outstanding activity in the probe reaction of alcoholysis of styrene oxide by methanol with 100%yield.Moreover,SFS-30 also shows a more excellent catalytic performance than bulk S2O82–-Fe2O3 towards the alcoholysis of other ROHs(R=C2H5-C4H9).Lewis and Bronsted acid sites on the SFS-30 surfaces are confirmed by pyridine adsorbed infrared spectra.The highly efficient catalytic activity of SFS-30 may be attributed to the synergistic effect from the nano-effect of S2O82–-Fe2O3 nanoparticles and the mesostructure of SBA-15.Finally,SFS-30 shows a good catalytic reusability,providing an 84.1%yield after seven catalytic cycles.
基金Supported by the National Natural Science Foundation of China(51009115)Shaanxi Provincial Department of Education Key Laboratory Project(13JS067)+2 种基金the Hall of Shaanxi Province Science and Technology(2013JK0881)the Research Plan Project of Water Resources Department of Shaanxi Province(2013slkj-07)the Innovation of Science and Technology Fund of Xi'an University of Technology(211302)
文摘Fe3O4 magnetic nanoparticles(MNPs) were synthesised, characterised, and used as a peroxidase mimetic to accelerate levofloxacin sono-degradation in an ultrasound(US)/H2O2 system. The Fe3O4 MNPs were in nanometre scale with an average diameter of approximately 12 to 18 nm. The introduction of Fe3O4 MNPs increased levofloxacin sono-degradation in the US/H2O2 system. Experimental parameters, such as Fe3O4 MNP dose, initial solution p H, and H2O2 concentration, were investigated by a one-factor-at-a-time approach. The results showed that Fe3O4 MNPs enhanced levofloxacin removal in the p H range from 4.0 to 9.0. Levofloxacin removal ratio increased with Fe3O4 MNP dose up to 1.0 g·L-1and with H2O2 concentration until reaching the maximum. Moreover, three main intermediate compounds were identified by HPLC with electrospray ionisation tandem mass spectrometry, and a possible degradation pathway was proposed. This study suggests that combination of H2O2, Fe3O4 MNPs and US is a good way to improve the degradation efficiency of antibiotics.
基金Supported by National Natural Science Foundation of China(Grant No.51175305)
文摘In recent decades, many additives with different characteristics have been applied to strengthen and toughen Al2O3-based ceramic cutting tool materials. Among them, SiC whiskers and SiC nanoparticles showed excellent performance in improving the material properties. While no attempts have been made to add SiC whiskers and SiC nanoparticles together into the ceramic matrix and the synergistically toughening effects of them have not been studied. An Al2O3-SiCw-SiC np advanced ceramic cutting tool material is fabricated by adding both one-dimensional SiC whiskers and zero-dimensional SiC nanoparticles into the Al2O3 matrix with an effective dispersing and mixing process. The composites with 25 vol% SiC whiskers and 25 vol% SiC nanoparticles alone are also investegated for comparison purposes. Results show that the Al2O3-SiCw-SiCnp composite with both 20 vo1% SiC whiskers and 5 vol% SiC nanoparticles additives have much improved mechanical properties. The flexural strength of Al2O3-SiCw-SiCnp is 730＋ 95 MPa and fracture toughness is 5.6 ± 0.6 MPa.m1/2. The toughening and strengthening mechanisms of SiC whiskers and nanoparticles are studied when they are added either individually or in combination. It is indicated that when SiC whiskers and nanoparticles are added together, the grains are further refined and homogenized, so that the microstructure and fracture mode ratio is modified. The SiC nanoparticles are found helpful to enhance the toughening effects of the SiC whiskers. The proposed research helps to enrich the types of ceramic cutting tool and is benefit to expand the application range of ceramic cutting tool.
文摘The Fe3O4@SiO2 composite nanoparticles were obtained from as-synthesized magnetite (Fe3O4) nanoparticles through the modified St?ber method. Then, the Fe3O4 nanoparticles and Fe3O4@SiO2 composite nanoparticles were characterized by means of X-ray diffraction (XRD), Raman spectra, scanning electron microscope (SEM) and vibrating sample magnetometer (VSM). Recently, the studies focus on how to improve the dispersion of composite particle and achieve good magnetic performance. Hence effects of the volume ratio of tetraethyl orthosilicate (TEOS) and magnetite colloid on the structural, morphological and magnetic properties of the composite nanoparticles were systematically investi-gated. The results revealed that the Fe3O4@SiO2 had better thermal stability and dispersion than the magnetite nanoparticles. Furthermore, the particle size and magnetic property of the Fe3O4@SiO2 composite nanoparticles can be adjusted by changing the volume ratio of TEOS and magnetite colloid.
基金Funded by the National Natural Science Foundation of China (50672089)the Encouraging Foundation for the Scientific Research of the Excellent Young and Middleaged Scientists in Shandong Province(2006BS04034)
文摘The film forming behavior on the interface between air and hydrosol of Fe2O3 nanoparticles was investigated by the surface pressure-time isotherms, the surface pressure-trough area isotherms, Brewster angle microscopy and transmission electron microscopy. It is found that the freshly prepared hydrosol of Fe2O3 nanoparticles is not stable. The surface pressure increases with the aging time and finally approaches a constant, and the smaller the concentration is, the smaller the surface pressure is stabilized at and the shorter the time the hydrosol reaching stable needs. The surface pressure also increases with compression until collapsed, and the longer the hydrosol is aged, the higher the collapsing pressure is. A uniform and compact film composed of nanoparticles with an average diameter of about 2-3 nm on the air-hydrosol interface is observed by Brewster angle microscope and transmission electron microscope.
文摘In order to modify inorganic particles as chromatic electrophoretic particles, an approach was designed and used to prepare Fe203 red electrophoretic particles. These Fe203-cationic hybrid nanoparticles （Fe203-CHNPs）were prepared through Fe203 core covered with polymer shell which was composed of SiO2 and P （DMAEMA-co-HMA） by using atom transfer radical polymerization （ATRP）technique. The SiO：-coating could introduce the functional group on the surfaceof inorganic particles, through which the polymer shell could be formed by using ATRP tech- nique. The results of Fourier transform infrared spectra （FT-IR）, X-ray photoelectron spectroscopy （XPS） and thermal gravimetric analysis （TGA）confirmed the chemical compositions of Fe2O3-CHNPs; the images of transmission elec- tron microscopy （TEM） indicated the core-shell structure of Fe2O3-CHNPs; the measurements of dynamic light scatter- ing （DLS） showed a 253.7 nm average particle size with narrow size distribution; and the zeta potential measurements identified the high chargeability of Fe2O3-CHNPs. Furthermore, the resulting nanoparticles were successfully applied in the electrophoretic display cell, which demonstrated that it was an effective approach to preparing chromatic elec- trophoretic particles.
文摘The properties of La 2O 3 doped molybdenum powder were studied. The La 2O 3 nanoparticles on the surface of molybdenum powder which is produced by the reduction of La(NO 3) 3 doped MoO 2 in hydrogen decrease the intensity of feature energy loss peak of molybdenum substrate; but increase that of peak of Mo?3d. The surface of molybdenum powder exposed to the atmosphere can be reduced because the surface is mainly covered with La 2O 3 nanoparticles. As a result, the capability of anti oxidation of molybdenum is improved.
基金Project(2011JQ028)supported by the Fundamental Research Funds for the Central Universities,ChinaProjects(2008SK3114,2010SK3113)supported by Hunan Provincial Science&Technology Plan,China+2 种基金Project(B2007086)supported by Science&Research Funds of Hunan Health Department,ChinaProject(12JJ5057)supported by Natural Science Foundation of Hunan Province,ChinaProjects(XCX1119,XCX12073)supported by University Students Innovative Experiment Plan Project of Hunan Agricultural University,China
文摘Highly biocompatible superparamagnetic Fe3O4 nanoparticles were synthesized by amide of folic acid （FA） ligands and the NH2-group onto the surface of Fe3O4 nanoparticles. The as-synthesized folate-conjugated Fe3O4 nanoparticles were characterized by X-ray diffraction diffractometer, transmission electron microscope, FT-IR spectrometer, vibrating sample magnetometer, and dynamic light scattering instrument. The in vivo labeling effect of folate-conjugated Fe3O4 nanoparticles on the hepatoma cells was investigated in tumor-bearing rat. The results demonstrate that the as-prepared nanoparticles have cubic structure of Fe3O4 with a particle size of about 8 nm and hydrated diameter of 25.7 nm at a saturation magnetization of 51 A·m2/kg. These nanoparticles possess good physiological stability, low cytotoxicity on human skin fibroblasts and negligible effect on Wistar rats at the concentration as high as 3 mg/kg body mass. The folate-conjugated Fe3O4 nanoparticles could be effectively mediated into the human hepatoma Bel 7402 cells through the binding of folate and folic acid receptor, enhancing the signal contrast of tumor tissue and surrounding normal tissue in MRI imaging. It is in favor of the tumor cells labeling, tracing, magnetic resonance imaging （MRI） target detection and magnetic hyperthermia.
文摘Precursor foam based Co incorporated α-Fe<sub>2</sub>O<sub>3</sub> (AFC) was successfully synthesized at 600℃ calcination temperature by simple solution method using PVA. The formation of α-Fe<sub>2</sub>O<sub>3</sub> nanoparticles was confirmed by X-ray diffraction measurement and reduction in crystallite size was found after cobalt incorporation. Field emission scanning electron microscopy revealed the existence of pyramidal shaped iron oxide in AFC. FTIR and Raman spectra also confirmed the presence of α-Fe<sub>2</sub>O<sub>3</sub>. Photocatalytic activity study showed that the cobalt incorporated α-Fe<sub>2</sub>O<sub>3</sub> was better photocatalyst than pure α-Fe<sub>2</sub>O<sub>3</sub>. The cobalt incorporated iron oxide nanoparticles could be used for drug delivery application and this simple preparation method could be adopted for the synthesis of other transition metal oxides.
基金Grant sponsor:National Natural Science Foundation of China,Grant number:30371830Grant sponsor:National Hi-tech research and development program of China,Grant number:2002AA302207+3 种基金 Grant sponsor:Natural Science Foundation of Jiangsu,Grant number:BK2001003Grant sponsor:Hi-tech research pro-gram of Jiangsu,Grant number:BG2001006 Grant sponsor:Key Project of Chinese Traditional Medicine of Jiangsu,Grant number:H027Grant sponsor:Sci-ence Foundation of Southeast University,Grant number:9223001162
文摘Objective：To evaluate the in vitro and in vivo toxicity of self-prepared nanosized Fe2O3, which has the potential implication in tumor hyperthermia. Methods： Fe2O3 nanoparticles were prepared by improving co-precipitation, which characterization was detected by TEM, XRD, CMIAS, EDS. MTT assay was used to evaluate the in vitro cytotoxicity test; hemolytic test was carried out to estimate whether it has blood toxicity; Fe2O3 suspended in sterile 0.9% NaCl was intraperitoneally injected into Kumning mouse to calculate the LD50 ; micronucleus （MN） were reckoned to identify whether it is genotoxic. Results：The nanoparticles are brown spherical particles with diameter ranging from 8 to 15 nm, which have good decentralization and stability. The experiments also showed that the toxicity of the material on mouse fibroblast （L-929） cell lines was 0 - 1 degree ; it has no hemolysis activity; LD50 arrived at 5.45 g/kg^-1 after intraperitoneal injection of 1 ml suspension; micronucleus test showed that it has no genotoxic effects either. Conclusion： The results showed that the Fe2O3 nanoparticles are prepared successfully, the self-prepared nanosized Fe2O3 is a kind of high biocompatibility materials and perhaps it is suitable for further application in tumor hyperthermia.
基金This work was supported by the National Natural Science Foundation of China （Nos. 90406023 and 60571031）；National Important Science Research Program of China （Nos. 2006CB933206 and 2006CB705606）.
文摘Peroxidase-like catalytic properties of Fe3O4 nanoparficles （NPs） with three different sizes, synthesized by chemical coprecipitation and sol-gel methods, were investigated by UV-vis spectrum analysis. By comparing Fe3O4 NPs with average diameters of 11, 20, and 150 nm, we found that the catalytic activity increases with the reduced nanoparticle size. The electrochemical method to characterize the catalytic activity of Fe3O4 NPs using the response currents of the reaction product and substrate was also developed.
基金This work was financially supported by the Graduate Innovation Plan Projects of Jiangsu Province in 2005.
文摘Fe3O4 nanoparticles were prepared by chemistry co-precipitation and the mean crystal size was 17.9 nm measured by XRD. After it had been treated by silane-coupling agents KH570, magnetic micro-spheres dispersed in organic medium glycol were gained and the mean size of Fe3O4 nanopowders was 33.7 nm. So it can be concluded that magnetic micro-sphere is made of a few Fe3O4 crystals. Many factors of modification were researched, such as the time of ball milling, the content of Fe3O4 and the content of KH570. The modification of Fe3O4 is relative to the time of ball milling, but the dominant function is affected by the content of Fe3O4 and KH570. When the content of Fe3O4 is known, there is a suitable content of KH570. Different content of Fe3O4 will make the different suitable content of KH570, but the range of latter is less than former, which is relative to the distribution of KH570 on Fe3O4 surface or in the solution.
基金the Foundation for the University by Educational Department of Liaoning (05L337)Key Laboratory of Rare Earth Chemistry and Physics, Chinese Academy of Sciences
文摘Y2O3： Er^3＋, Yb^3＋ nanoparticles were synthesized by a homogeneous precipitation method without and with different concentrations of EDTA 2Na. Upconversion luminescence spectra of the samples were studied under 980 nm laser excitation. The results of XRD showed that the obtained Y2O3：Er^3＋,Yb^3＋ nanoparticles were of a cubic structure. The average crystallite sizes calculated were in the range of 28-40 nm. Green and red upconversion emission were observed, and attributed to ^2H11/2,^4S3/2→^4I15/2 and ^4F9/2→^4I15/2 transitions of the ion, respectively. The ratio of the intensity of green emission to that of red emission drastically changed with a change in the EDTA 2Na concentration. In the sample synthesized without EDTA, the relative intensity of the green emission was weaker than that of the red emission. The relative intensities of green emission increased with the increased amount of EDTA 2Na used. The possible upconversion luminescence mechanisms were discussed.
