The core-shell particles consisting of poly(butyl acrylate)(PBA) core and silica shell were synthesized. The 3-methacryloxy propyl trimethoxysilane (MPS) was used as functional comonomer to modify the PBA latex partic...The core-shell particles consisting of poly(butyl acrylate)(PBA) core and silica shell were synthesized. The 3-methacryloxy propyl trimethoxysilane (MPS) was used as functional comonomer to modify the PBA latex particle surface with silanol(SiOH) groups via semicontinuous emulsion polymerization. The resulted emulsion was transferred into water/ethanol mixture without loss of stability and functionalized PBA latex was used as seeds for further silica shell growth. The coating process was achieved by Stber method, base-catalyzed hydrolysis and condensation of tetraethoxysilane(TEOS). The functionalized latex and core/shell particles were characterized by using differential thermal analysis(DTA), transmission electron microscope and light scattering. It has been confirmed that the PBA latex particles have been entirely enveloped with silica shell and the core/shell particles are monodisperse. The thickness of silica shell can be estimated by the size difference of functionalized PBA-SiO 2 core-shell particles.展开更多
We prepared Au/Ag core-shell nanoparticles by growing Ag shell onto 12 nm Au core, using silver nitrate and sodium citrate as the reactants. By changing the molar ratio of Ag to Au, the shell thickness and thus the si...We prepared Au/Ag core-shell nanoparticles by growing Ag shell onto 12 nm Au core, using silver nitrate and sodium citrate as the reactants. By changing the molar ratio of Ag to Au, the shell thickness and thus the size of bimetallic particles could be controlled in convenient way. The formation of core-shell structure was proved by UV-Vis spectra, transmission electron microscopy(TEM), etc.. The core-shell particles showed a more narrow size distribution than Ag colloid prepared without Au core. The SERS activity of the core-shell particles was investigated by using 2,4-dimethylpyridine as the probe, which strongly indicated their potential application in SERS substrate materials.展开更多
通过异质核诱导,利用溶剂热法在较低温度下合成了具有疏水表面的上转换发光稀土核-壳Na YF4/Na Lu F4∶20%Yb,1%Tm纳米粒子,并利用X射线衍射仪、透射电子显微镜、傅里叶变换红外吸收光谱仪以及荧光光谱仪等测试设备对其进行了结构、形...通过异质核诱导,利用溶剂热法在较低温度下合成了具有疏水表面的上转换发光稀土核-壳Na YF4/Na Lu F4∶20%Yb,1%Tm纳米粒子,并利用X射线衍射仪、透射电子显微镜、傅里叶变换红外吸收光谱仪以及荧光光谱仪等测试设备对其进行了结构、形貌和上转换光谱的表征。测试结果表明,纳米粒子核为立方相,壳层为六角相。核-壳型纳米粒子的尺寸平均在20 nm以下,分布较为均匀。在980 nm近红外光激发下,核-壳型纳米粒子发射出较强的紫色和紫外荧光,且发光强度明显高于同尺寸立方相Na Lu F4∶20%Yb,1%Tm纳米粒子。这表明利用异质核诱导的方法制备的核-壳型纳米粒子在生物医学领域具有更高的应用价值。展开更多
文摘The core-shell particles consisting of poly(butyl acrylate)(PBA) core and silica shell were synthesized. The 3-methacryloxy propyl trimethoxysilane (MPS) was used as functional comonomer to modify the PBA latex particle surface with silanol(SiOH) groups via semicontinuous emulsion polymerization. The resulted emulsion was transferred into water/ethanol mixture without loss of stability and functionalized PBA latex was used as seeds for further silica shell growth. The coating process was achieved by Stber method, base-catalyzed hydrolysis and condensation of tetraethoxysilane(TEOS). The functionalized latex and core/shell particles were characterized by using differential thermal analysis(DTA), transmission electron microscope and light scattering. It has been confirmed that the PBA latex particles have been entirely enveloped with silica shell and the core/shell particles are monodisperse. The thickness of silica shell can be estimated by the size difference of functionalized PBA-SiO 2 core-shell particles.
文摘We prepared Au/Ag core-shell nanoparticles by growing Ag shell onto 12 nm Au core, using silver nitrate and sodium citrate as the reactants. By changing the molar ratio of Ag to Au, the shell thickness and thus the size of bimetallic particles could be controlled in convenient way. The formation of core-shell structure was proved by UV-Vis spectra, transmission electron microscopy(TEM), etc.. The core-shell particles showed a more narrow size distribution than Ag colloid prepared without Au core. The SERS activity of the core-shell particles was investigated by using 2,4-dimethylpyridine as the probe, which strongly indicated their potential application in SERS substrate materials.
文摘通过异质核诱导,利用溶剂热法在较低温度下合成了具有疏水表面的上转换发光稀土核-壳Na YF4/Na Lu F4∶20%Yb,1%Tm纳米粒子,并利用X射线衍射仪、透射电子显微镜、傅里叶变换红外吸收光谱仪以及荧光光谱仪等测试设备对其进行了结构、形貌和上转换光谱的表征。测试结果表明,纳米粒子核为立方相,壳层为六角相。核-壳型纳米粒子的尺寸平均在20 nm以下,分布较为均匀。在980 nm近红外光激发下,核-壳型纳米粒子发射出较强的紫色和紫外荧光,且发光强度明显高于同尺寸立方相Na Lu F4∶20%Yb,1%Tm纳米粒子。这表明利用异质核诱导的方法制备的核-壳型纳米粒子在生物医学领域具有更高的应用价值。
