To improve the magneto-rheological (MR) properties of magneto-rheological fluids, self-made amorphous alloy particles, the composition of which was Fe76Cr2Mo2Sn2P10B2C2Si4, were used as the disperse phase to replace t...To improve the magneto-rheological (MR) properties of magneto-rheological fluids, self-made amorphous alloy particles, the composition of which was Fe76Cr2Mo2Sn2P10B2C2Si4, were used as the disperse phase to replace traditional carbonyl iron (CI) particles to prepare amorphous based magneto-rheological fluid (AMRF). Soft magnetic properties and densities of the amorphous particles and the CI particles were tested and compared. The results indicate the amorphous particles present a lower density but larger magnetization intensity and larger permeability at lower field levels. Properties of the AMRF with 20% particles in volume fraction were tested and compared with the CI based MR fluid (CMRF). The AMRF presents a saturation yield stress of 41 kPa at ~227 kA/m and a sedimentation ratio of 80%. The results indicate the magneto-rheological fluid based on amorphous micro-particles has better MR properties and sedimentation stability than that based on CI particles at lower field levels (0-200 kA/m).展开更多
Magnetic starch particles （MSPs） were synthesized in water-in-oil mieroemulsion at room temperature. MSPs were characterized by transmission electron microscopy （TEM）, Fourier transform infrared spectrometry （FTI...Magnetic starch particles （MSPs） were synthesized in water-in-oil mieroemulsion at room temperature. MSPs were characterized by transmission electron microscopy （TEM）, Fourier transform infrared spectrometry （FTIR）, zeta potential system, thermogravimetric analysis （TGA） and vibrating sample magnetometry （VSM）. The average diameter of the MSPs was 220 nm, dispersed with well-proportioned size and magnetic resonance, the saturation magnetization was 3.64 A.mR/kg. MSP was coated with poly-L-lysine （PLL）, and then the surface of PLL-MSP was combined with fluorescein isothiocynate （FITC）. Results show that fluorescent/magnetic starch particles （FMSPs） are of stable photo-bleaching capability compared with free FITC, with low bio-toxicity and certain function of magnetic separation. It is expected that FMSPs are bifimctional nano-materials including fluorescence labelling and magnetic separation.展开更多
The effect of γ-Fe_2O_3 nanoparticles on bisphenol A(BPA)biodegradation by white rot fungus(Pleurotus ostreatus)was investigated.Interestingly,the addition of γ-Fe_2O_3 nanoparticles enhanced BPA degradation efficie...The effect of γ-Fe_2O_3 nanoparticles on bisphenol A(BPA)biodegradation by white rot fungus(Pleurotus ostreatus)was investigated.Interestingly,the addition of γ-Fe_2O_3 nanoparticles enhanced BPA degradation efficiency by as much as 32% after 3 d in the presence of an environmentally relevant concentration of H_2O_2.The γ-Fe_2O_3-induced BPA degradation enhancement was not due to a commonly assumed Fenton-like reaction catalyzed by γ-Fe_2O_3 or dissolved Fe^(3+) ions.However,γ-Fe_2O_3was bioreduced to Fe_3O_4,which was more efficient at catalyzing the Fenton reaction,producing a highly active hydroxyl radical.The bioreduction of γ-Fe_2O_3 was confirmed by X-ray powder diffraction analysis.This study elucidates the potential biotransformation of nanoparticles in the environment and broadens the application of iron oxide nanoparticles for improved pollutant control.展开更多
基金Project (51108062) supported by the National Natural Science Foundation of ChinaProject(20100471446) supported by the China Postdoctoral Science Foundation
文摘To improve the magneto-rheological (MR) properties of magneto-rheological fluids, self-made amorphous alloy particles, the composition of which was Fe76Cr2Mo2Sn2P10B2C2Si4, were used as the disperse phase to replace traditional carbonyl iron (CI) particles to prepare amorphous based magneto-rheological fluid (AMRF). Soft magnetic properties and densities of the amorphous particles and the CI particles were tested and compared. The results indicate the amorphous particles present a lower density but larger magnetization intensity and larger permeability at lower field levels. Properties of the AMRF with 20% particles in volume fraction were tested and compared with the CI based MR fluid (CMRF). The AMRF presents a saturation yield stress of 41 kPa at ~227 kA/m and a sedimentation ratio of 80%. The results indicate the magneto-rheological fluid based on amorphous micro-particles has better MR properties and sedimentation stability than that based on CI particles at lower field levels (0-200 kA/m).
基金Project(200501) supported by the "985" Program of China
文摘Magnetic starch particles （MSPs） were synthesized in water-in-oil mieroemulsion at room temperature. MSPs were characterized by transmission electron microscopy （TEM）, Fourier transform infrared spectrometry （FTIR）, zeta potential system, thermogravimetric analysis （TGA） and vibrating sample magnetometry （VSM）. The average diameter of the MSPs was 220 nm, dispersed with well-proportioned size and magnetic resonance, the saturation magnetization was 3.64 A.mR/kg. MSP was coated with poly-L-lysine （PLL）, and then the surface of PLL-MSP was combined with fluorescein isothiocynate （FITC）. Results show that fluorescent/magnetic starch particles （FMSPs） are of stable photo-bleaching capability compared with free FITC, with low bio-toxicity and certain function of magnetic separation. It is expected that FMSPs are bifimctional nano-materials including fluorescence labelling and magnetic separation.
基金supported by the National Basic Research Program of China (2014CB932001)the National Natural Science Foundation of China (21237002)the Tianjin Municipal Science and Technology Commission (13JCZDJC35900)
文摘The effect of γ-Fe_2O_3 nanoparticles on bisphenol A(BPA)biodegradation by white rot fungus(Pleurotus ostreatus)was investigated.Interestingly,the addition of γ-Fe_2O_3 nanoparticles enhanced BPA degradation efficiency by as much as 32% after 3 d in the presence of an environmentally relevant concentration of H_2O_2.The γ-Fe_2O_3-induced BPA degradation enhancement was not due to a commonly assumed Fenton-like reaction catalyzed by γ-Fe_2O_3 or dissolved Fe^(3+) ions.However,γ-Fe_2O_3was bioreduced to Fe_3O_4,which was more efficient at catalyzing the Fenton reaction,producing a highly active hydroxyl radical.The bioreduction of γ-Fe_2O_3 was confirmed by X-ray powder diffraction analysis.This study elucidates the potential biotransformation of nanoparticles in the environment and broadens the application of iron oxide nanoparticles for improved pollutant control.
