Magnetic nanoparticles （Fe304） were prepared by chemical precipitation method using Fe^2＋ and Fe^3＋ salts with sodium hydroxide in the nitrogen atmosphere. Fe3O4 nanoparticles were coated with human serum albumin...Magnetic nanoparticles （Fe304） were prepared by chemical precipitation method using Fe^2＋ and Fe^3＋ salts with sodium hydroxide in the nitrogen atmosphere. Fe3O4 nanoparticles were coated with human serum albumin（HSA） for magnetic resonance imaging as contrast agent. Characteristics of magnetic particles coated or uncoated were carried out using scanning electron microscopy and X-ray diffraction. Zeta potentials, package effects and distributions of colloid particles were measured to confirm the attachment of HSA on magnetic particles. Effects of Fe3O4 nanoparticles coated with HSA on magnetic resonance imaging were investigated with rats. The experimental results show that the adsorption of HSA on magnetic particles is very favorable to dispersing of magnetic Fe3O4 particles, while the sizes of Fe3O4 particles coated are related to the molar ratio of Fe3O4 to HSA. The diameters of the majority of particles coated are less than 100 nm. Fe3O4 nanoparticle coated with HSA has a good biocompatibility and low toxicity. This new contrast agent has some effects on the nuclear magnetic resonance imaging of liver and the lowest dosage is 20μmol/kg for the demands of diagnosis.展开更多
Fe3O4 magnetic nanoparticles with diameters varying from 10 to 426 nm were synthesized and characterized.Heating effects of Fe3O4 magnetic nanoparticles under radiofrequency capacitive field(RCF) with frequency of 27....Fe3O4 magnetic nanoparticles with diameters varying from 10 to 426 nm were synthesized and characterized.Heating effects of Fe3O4 magnetic nanoparticles under radiofrequency capacitive field(RCF) with frequency of 27.12 MHz and power of 60-150 W were investigated.When the power of RCF is lower than 90 W,temperatures of Fe3O4 magnetic nanoparticles(75-150 mg/mL) can be raised and maximal temperatures are all lower than 50 ℃.When the power of RCF is 90-150 W,temperatures of Fe3O4 magnetic nanoparticles can be quickly raised and are all obviously higher than those of normal saline and distilled water under the same conditions.Temperature of Fe3O4 magnetic nanoparticles can even reach 70.2 ℃ under 150 W RCF.Heating effects of Fe3O4 magnetic nanoparticles are related to RCF power,particle size and particle concentration.展开更多
Nanocomposites of PAn-DBSA/γ-Fe 2O 3 with electrical and ferromagnetic behavior(σ= 2.18×10 -3-5.00×10 -5 S/cm, M s=3.7-16.6 m 2·A/kg, H c=8 805.2-9 133.1 A/m) were prepared by a chemical modification-...Nanocomposites of PAn-DBSA/γ-Fe 2O 3 with electrical and ferromagnetic behavior(σ= 2.18×10 -3-5.00×10 -5 S/cm, M s=3.7-16.6 m 2·A/kg, H c=8 805.2-9 133.1 A/m) were prepared by a chemical modification-redoping method in a neutral medium. The products were characterized by TEM, XRD, UV-Vis, four-probe method, and magnetometer. The results indicate that the electrical and magnetic properties of the nanocomposites strongly depend on γ-Fe 2O 3 content. With the increase of γ-Fe 2O 3 content, the electrical conductivity is decreased and saturation magnetization is increased.展开更多
采用油包水（W/O）微乳液法,以KBH4为还原剂,在水相-Triton X 100-异丙醇-环己烷组成的W/O微乳液中还原二价铁、钴、镍盐,合成Fe-Co-Ni合金纳米微粒。考察反应气氛、温度、时间和洗涤溶液对反应的影响,并用X射线衍射仪、扫描电子显微镜...采用油包水（W/O）微乳液法,以KBH4为还原剂,在水相-Triton X 100-异丙醇-环己烷组成的W/O微乳液中还原二价铁、钴、镍盐,合成Fe-Co-Ni合金纳米微粒。考察反应气氛、温度、时间和洗涤溶液对反应的影响,并用X射线衍射仪、扫描电子显微镜对合成的纳米微粒的形貌、结构进行检测。研究结果表明：在25-30℃的N2中反应1 h,得到的产物待丙酮破乳后用无水乙醇洗涤结果最佳。合成的Fe-Co-Ni合金是粒径为1-3 nm的球状微粒。展开更多
文摘Magnetic nanoparticles （Fe304） were prepared by chemical precipitation method using Fe^2＋ and Fe^3＋ salts with sodium hydroxide in the nitrogen atmosphere. Fe3O4 nanoparticles were coated with human serum albumin（HSA） for magnetic resonance imaging as contrast agent. Characteristics of magnetic particles coated or uncoated were carried out using scanning electron microscopy and X-ray diffraction. Zeta potentials, package effects and distributions of colloid particles were measured to confirm the attachment of HSA on magnetic particles. Effects of Fe3O4 nanoparticles coated with HSA on magnetic resonance imaging were investigated with rats. The experimental results show that the adsorption of HSA on magnetic particles is very favorable to dispersing of magnetic Fe3O4 particles, while the sizes of Fe3O4 particles coated are related to the molar ratio of Fe3O4 to HSA. The diameters of the majority of particles coated are less than 100 nm. Fe3O4 nanoparticle coated with HSA has a good biocompatibility and low toxicity. This new contrast agent has some effects on the nuclear magnetic resonance imaging of liver and the lowest dosage is 20μmol/kg for the demands of diagnosis.
基金Projects(30571779,10775085) supported by the National Natural Science Foundation of ChinaProject(Z07000200540704) supported by Beijing Municipal Science and Technology Commission,China
文摘Fe3O4 magnetic nanoparticles with diameters varying from 10 to 426 nm were synthesized and characterized.Heating effects of Fe3O4 magnetic nanoparticles under radiofrequency capacitive field(RCF) with frequency of 27.12 MHz and power of 60-150 W were investigated.When the power of RCF is lower than 90 W,temperatures of Fe3O4 magnetic nanoparticles(75-150 mg/mL) can be raised and maximal temperatures are all lower than 50 ℃.When the power of RCF is 90-150 W,temperatures of Fe3O4 magnetic nanoparticles can be quickly raised and are all obviously higher than those of normal saline and distilled water under the same conditions.Temperature of Fe3O4 magnetic nanoparticles can even reach 70.2 ℃ under 150 W RCF.Heating effects of Fe3O4 magnetic nanoparticles are related to RCF power,particle size and particle concentration.
文摘Nanocomposites of PAn-DBSA/γ-Fe 2O 3 with electrical and ferromagnetic behavior(σ= 2.18×10 -3-5.00×10 -5 S/cm, M s=3.7-16.6 m 2·A/kg, H c=8 805.2-9 133.1 A/m) were prepared by a chemical modification-redoping method in a neutral medium. The products were characterized by TEM, XRD, UV-Vis, four-probe method, and magnetometer. The results indicate that the electrical and magnetic properties of the nanocomposites strongly depend on γ-Fe 2O 3 content. With the increase of γ-Fe 2O 3 content, the electrical conductivity is decreased and saturation magnetization is increased.
文摘采用油包水（W/O）微乳液法,以KBH4为还原剂,在水相-Triton X 100-异丙醇-环己烷组成的W/O微乳液中还原二价铁、钴、镍盐,合成Fe-Co-Ni合金纳米微粒。考察反应气氛、温度、时间和洗涤溶液对反应的影响,并用X射线衍射仪、扫描电子显微镜对合成的纳米微粒的形貌、结构进行检测。研究结果表明：在25-30℃的N2中反应1 h,得到的产物待丙酮破乳后用无水乙醇洗涤结果最佳。合成的Fe-Co-Ni合金是粒径为1-3 nm的球状微粒。
基金supported by the National Key Basic Research Program of China(973)(2012CB722805)National Natural Science Foundation of China(50504010,50974083,51174131)+1 种基金Joint Funds of National Natural Science Foundation of China-Steel,China(50774112)"Phosphor"Project of Shanghai Science and Technology Development Funds,China(07QA4021)~~
