Ferromagnetic Fe3O4 nanoparticles were synthesized using water as the solvent through the sol-gel method, which was selected for its cost-effectiveness, simplicity, and eco-friendly nature. The synthesized nanoparticl...Ferromagnetic Fe3O4 nanoparticles were synthesized using water as the solvent through the sol-gel method, which was selected for its cost-effectiveness, simplicity, and eco-friendly nature. The synthesized nanoparticles were characterized using a variety of techniques, including Fourier Transform Infrared (FTIR) spectroscopy, X-ray powder diffraction (XRD), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA), and Vibrating Sample Magnetometer (VSM). These characterizations confirmed the successful formation of Fe3O4 nanoparticles. The FTIR spectra identified characteristic peaks corresponding to the functional groups present, and XRD analysis, using Scherer’s equation, determined an average crystalline size of 1.2 nm for the Fe3O4 nanoparticles. TGA results demonstrated the thermal stability of the nanoparticles, SEM imaging revealed distinct honeycomb-like structures for the nanoparticles synthesized with water as the solvent, while the VSM analysis was used to determine the magnetic behavior of the nanoparticles.展开更多
In this study,the preparation of a new kind of magnetic and luminescent Fe3O4/CdTe nanocomposites was demonstrated. Superparamagnetic Fe3O4 nanoparticles were first synthesized by hydrothermal coprecipitation of ferri...In this study,the preparation of a new kind of magnetic and luminescent Fe3O4/CdTe nanocomposites was demonstrated. Superparamagnetic Fe3O4 nanoparticles were first synthesized by hydrothermal coprecipitation of ferric and ferrous ions,followed by the modification of their surfaces with tetramethylammonium hydroxide（TMAOH） and the chemical activation with aspartic acid.The surface-modified Fe3O4 nanoparticles were then covalently coated with CdTe quantum dots（QDs）,which were modified with mercaptoacetic acid（MPA）,to form the Fe3O4/CdTe magnetic and luminescent nanocomposites through the coordination of the amino groups on the surfaces of Fe3O4 and the carboxyl groups on CdTe QDs.The structure and properties of as-synthesized nanocomposites were characterized.It was indicated that the nanocomposites possessed structure with an average diameter of 40- 50 nm,yellow-green emission feature and room temperature ferro-magnetism.Both the fluorescence and UV-vis absorption spectra of the nanocomposites showed a blue shift comparing with those of CdTe QDs.The mechanism of the blue shift was presented.The nanocomposites retained the ferromagnetic property with a saturation magnetization of 8.9 emu/g.展开更多
本文通过层层自组装技术（1ayer-by—layer，LBL）成功制备了CdTe@Fe3O4磁性荧光复合纳米粒子，并对其特性和应用进行了讨论．首先，采用化学共沉淀法，以NaOH为沉淀剂，Fe^2＋和Fe^3＋物质的量的比为1：2．在50℃水相中电磁搅拌30min...本文通过层层自组装技术（1ayer-by—layer，LBL）成功制备了CdTe@Fe3O4磁性荧光复合纳米粒子，并对其特性和应用进行了讨论．首先，采用化学共沉淀法，以NaOH为沉淀剂，Fe^2＋和Fe^3＋物质的量的比为1：2．在50℃水相中电磁搅拌30min，制备出具有磁性的纳米Fe3O4，然后表面修饰1,6-己二胺．通过透射电镜（transmission electron microscopy,TEM）对其进行观察，粒径在10nm左右．核壳cdTe@Fe3O4复合功能纳米粒子的合成表明：Fe3O4和cdTc物质的量的比为1：3，pH=6．0，温度30℃，反应时间30min为其最佳合成条件．通过TEM、紫外和荧光光谱对合成的纳米粒子分别进行了表征．cdTe@Fe3O4粒径在12～15nm，最大发射波长从530nm红移到570nm，而最大吸收波长则从530nm红移到535mm．结果表明，磁性Fe3O4表面成功覆盖了CdTe壳层．核壳型CdTe@Fe3O4磁性荧光复合纳米粒子的应用能够实现对DNA进行简便快捷的标记、传感和分离．展开更多
文摘Ferromagnetic Fe3O4 nanoparticles were synthesized using water as the solvent through the sol-gel method, which was selected for its cost-effectiveness, simplicity, and eco-friendly nature. The synthesized nanoparticles were characterized using a variety of techniques, including Fourier Transform Infrared (FTIR) spectroscopy, X-ray powder diffraction (XRD), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA), and Vibrating Sample Magnetometer (VSM). These characterizations confirmed the successful formation of Fe3O4 nanoparticles. The FTIR spectra identified characteristic peaks corresponding to the functional groups present, and XRD analysis, using Scherer’s equation, determined an average crystalline size of 1.2 nm for the Fe3O4 nanoparticles. TGA results demonstrated the thermal stability of the nanoparticles, SEM imaging revealed distinct honeycomb-like structures for the nanoparticles synthesized with water as the solvent, while the VSM analysis was used to determine the magnetic behavior of the nanoparticles.
基金supported by the National Natural Science Foundation of China(Nos.20345006 and 20575043)
文摘In this study,the preparation of a new kind of magnetic and luminescent Fe3O4/CdTe nanocomposites was demonstrated. Superparamagnetic Fe3O4 nanoparticles were first synthesized by hydrothermal coprecipitation of ferric and ferrous ions,followed by the modification of their surfaces with tetramethylammonium hydroxide（TMAOH） and the chemical activation with aspartic acid.The surface-modified Fe3O4 nanoparticles were then covalently coated with CdTe quantum dots（QDs）,which were modified with mercaptoacetic acid（MPA）,to form the Fe3O4/CdTe magnetic and luminescent nanocomposites through the coordination of the amino groups on the surfaces of Fe3O4 and the carboxyl groups on CdTe QDs.The structure and properties of as-synthesized nanocomposites were characterized.It was indicated that the nanocomposites possessed structure with an average diameter of 40- 50 nm,yellow-green emission feature and room temperature ferro-magnetism.Both the fluorescence and UV-vis absorption spectra of the nanocomposites showed a blue shift comparing with those of CdTe QDs.The mechanism of the blue shift was presented.The nanocomposites retained the ferromagnetic property with a saturation magnetization of 8.9 emu/g.
文摘本文通过层层自组装技术（1ayer-by—layer，LBL）成功制备了CdTe@Fe3O4磁性荧光复合纳米粒子，并对其特性和应用进行了讨论．首先，采用化学共沉淀法，以NaOH为沉淀剂，Fe^2＋和Fe^3＋物质的量的比为1：2．在50℃水相中电磁搅拌30min，制备出具有磁性的纳米Fe3O4，然后表面修饰1,6-己二胺．通过透射电镜（transmission electron microscopy,TEM）对其进行观察，粒径在10nm左右．核壳cdTe@Fe3O4复合功能纳米粒子的合成表明：Fe3O4和cdTc物质的量的比为1：3，pH=6．0，温度30℃，反应时间30min为其最佳合成条件．通过TEM、紫外和荧光光谱对合成的纳米粒子分别进行了表征．cdTe@Fe3O4粒径在12～15nm，最大发射波长从530nm红移到570nm，而最大吸收波长则从530nm红移到535mm．结果表明，磁性Fe3O4表面成功覆盖了CdTe壳层．核壳型CdTe@Fe3O4磁性荧光复合纳米粒子的应用能够实现对DNA进行简便快捷的标记、传感和分离．
