In this paper,chemical co-precipitation method was employed to synthesize Fe3O4 nanoparticles which can be well dispersed in water by using citric acid as a surfactant.Afterwards,by using Fe3O4 nanoparticles as seeds ...In this paper,chemical co-precipitation method was employed to synthesize Fe3O4 nanoparticles which can be well dispersed in water by using citric acid as a surfactant.Afterwards,by using Fe3O4 nanoparticles as seeds in a Triton X-100/hexanol/cyclohexane/water reverse microemulsion system,the core-shell structural Fe3O4@SiO2 nanocomposite particles were prepared via hydrolysis and condensation of tetraethyl orthosilicate(TEOS) under the catalysis of alkali.The effects of different stirring methods and the concentration of TEOS on the morphology of Fe3O4@SiO2 nanoparticles were investigated.The results show that the mechanical stirring can effectively control the morphology of composite nanoparticles to form a good dispersion and spherical morphology of core-shell nanoparticles.With the increase of TEOS concentration,the thickness of the SiO2 shell increases,and the morphology of the composite particles becomes more uniform.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
Nanoparticles of polystyrene/α Fe 2O 3 composites were prepared by method of insertion in sodium dodecylbenzene sulfonate(SDBS) micellar system. The orange α Fe 2O 3 particles of about 6 nm were first prepared from ...Nanoparticles of polystyrene/α Fe 2O 3 composites were prepared by method of insertion in sodium dodecylbenzene sulfonate(SDBS) micellar system. The orange α Fe 2O 3 particles of about 6 nm were first prepared from 0 25 mol/L FeCl 2 and (NH 3) 2CO 3 in 0.1% surfactant solution at pH=4, 105 ℃ for 10 h. The title nanoparticles were prepared then in conditions of SDBS∶ styrene∶H 2O(mass fraction)=0 1∶1∶9, 85 ℃, 8 h, using ammonium persulfate(APS) as an initiator. The composite nanoparticles sized in 20～50 nm and showed magnetic property.展开更多
文摘In this paper,chemical co-precipitation method was employed to synthesize Fe3O4 nanoparticles which can be well dispersed in water by using citric acid as a surfactant.Afterwards,by using Fe3O4 nanoparticles as seeds in a Triton X-100/hexanol/cyclohexane/water reverse microemulsion system,the core-shell structural Fe3O4@SiO2 nanocomposite particles were prepared via hydrolysis and condensation of tetraethyl orthosilicate(TEOS) under the catalysis of alkali.The effects of different stirring methods and the concentration of TEOS on the morphology of Fe3O4@SiO2 nanoparticles were investigated.The results show that the mechanical stirring can effectively control the morphology of composite nanoparticles to form a good dispersion and spherical morphology of core-shell nanoparticles.With the increase of TEOS concentration,the thickness of the SiO2 shell increases,and the morphology of the composite particles becomes more uniform.
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．
文摘Nanoparticles of polystyrene/α Fe 2O 3 composites were prepared by method of insertion in sodium dodecylbenzene sulfonate(SDBS) micellar system. The orange α Fe 2O 3 particles of about 6 nm were first prepared from 0 25 mol/L FeCl 2 and (NH 3) 2CO 3 in 0.1% surfactant solution at pH=4, 105 ℃ for 10 h. The title nanoparticles were prepared then in conditions of SDBS∶ styrene∶H 2O(mass fraction)=0 1∶1∶9, 85 ℃, 8 h, using ammonium persulfate(APS) as an initiator. The composite nanoparticles sized in 20～50 nm and showed magnetic property.
