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
One kind of well-defined lead sulfide nano-particles was synthesized according to the literature method and characterized by FE-SEM and XRD. Then,silica-coated lead sulfide submicron particles were prepared with the a...One kind of well-defined lead sulfide nano-particles was synthesized according to the literature method and characterized by FE-SEM and XRD. Then,silica-coated lead sulfide submicron particles were prepared with the aid of sonication in a short time. TEM,XRD and XPS were used to observe and analyze the shape and structure of the as-prepared lead sulfide/silica core-shell submicron particles. The results indicate that the lead sulfide nano-crystallines are well coated by amorphous silica with adjustable thickness. After preparation of lead sulfide/silica composite particles,their fluorescence property was further studied.展开更多
Fe oxide core/Au shell nanoparticles were prepared by the reduction of Au3+ onto the surfaces of Fe oxide nanoparticles and characterized by scanning electron microscopy(SEM). The results reveal that the prepared core...Fe oxide core/Au shell nanoparticles were prepared by the reduction of Au3+ onto the surfaces of Fe oxide nanoparticles and characterized by scanning electron microscopy(SEM). The results reveal that the prepared core/shell nanoparticles were covered by Au shell and the surfaces of the core/shell particles are jagged after the initial addition of Au3+. Surface enhanced Raman scattering(SERS) activities of these magnetic nanoparticles were studied by using pyridine(Py) as a probe molecule after a magnet was used to concentrate the colloid. It was found that the SERS intensity depends on the Au shell thickness of the core/shell nanoparticles and strengthens with the increasing shell thickness. The detection limit for Py can be very low when the magnetic Fe oxide core/Au shell nanoparticles were used and even down to 10-7 mol/L.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One kind of well-defined lead sulfide nano-particles was synthesized according to the literature method and characterized by FE-SEM and XRD. Then,silica-coated lead sulfide submicron particles were prepared with the aid of sonication in a short time. TEM,XRD and XPS were used to observe and analyze the shape and structure of the as-prepared lead sulfide/silica core-shell submicron particles. The results indicate that the lead sulfide nano-crystallines are well coated by amorphous silica with adjustable thickness. After preparation of lead sulfide/silica composite particles,their fluorescence property was further studied.
文摘Fe oxide core/Au shell nanoparticles were prepared by the reduction of Au3+ onto the surfaces of Fe oxide nanoparticles and characterized by scanning electron microscopy(SEM). The results reveal that the prepared core/shell nanoparticles were covered by Au shell and the surfaces of the core/shell particles are jagged after the initial addition of Au3+. Surface enhanced Raman scattering(SERS) activities of these magnetic nanoparticles were studied by using pyridine(Py) as a probe molecule after a magnet was used to concentrate the colloid. It was found that the SERS intensity depends on the Au shell thickness of the core/shell nanoparticles and strengthens with the increasing shell thickness. The detection limit for Py can be very low when the magnetic Fe oxide core/Au shell nanoparticles were used and even down to 10-7 mol/L.
