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
The preparation and formation mechanism of silica/polyvinylpyrrolidone(PVP)-polyacrylonitrile(PAN) coaxial nanofibers were presented in this paper. The PVP-PAN composite nanofibers were obtained via an electrospin...The preparation and formation mechanism of silica/polyvinylpyrrolidone(PVP)-polyacrylonitrile(PAN) coaxial nanofibers were presented in this paper. The PVP-PAN composite nanofibers were obtained via an electrospinning technique, while SiO2 nanoparticles were prepared according to a Stber method. The measurements of water contact angle(WCA), the compared results of silica coating PVP-PAN composite nanofibers with PAN nanofibers indicate that much PVP resided on the composite nanofiber surface, which results in the occurrence of SiO2@polymer coaxial nanofibers due to the formation of hydrogen bonding between silica and composite nanofibers and subsequent adsorption of silica on the fiber surface.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The preparation and formation mechanism of silica/polyvinylpyrrolidone(PVP)-polyacrylonitrile(PAN) coaxial nanofibers were presented in this paper. The PVP-PAN composite nanofibers were obtained via an electrospinning technique, while SiO2 nanoparticles were prepared according to a Stber method. The measurements of water contact angle(WCA), the compared results of silica coating PVP-PAN composite nanofibers with PAN nanofibers indicate that much PVP resided on the composite nanofiber surface, which results in the occurrence of SiO2@polymer coaxial nanofibers due to the formation of hydrogen bonding between silica and composite nanofibers and subsequent adsorption of silica on the fiber surface.