pH-Responsive hollow polymeric microspheres and concentric hollow silica microspheres from silica-polymer core-shell microspheres
writer：Guoliang Li, Gang Liu, E. T. Kang*, K. G. Neoh, Xinlin Yang*
keywords：Silica/polymer core-shell microsphere; Distillation precipitation polymerization
source：期刊
specific source：Langmuir, 24 (16), 9050-9055 (2008). DOI: 10.1021/la8010579
Issue time：2008年
Nearly monodispersed silica-poly(methacrylic acid) (SiO2-PMAA) core-shell microspheres were synthesized by distillation-precipitation polymerization from 3-(trimethoxysilyl)propylmethacrylate-silica (SiO2-MPS) particle templates. SiO2-PMAA-SiO2 trilayer hybrid microspheres were subsequently prepared by coating of an outer layer of SiO2 on the SiO2-PMAAcore-shell microspheres in a sol-gel process. pH-ResponsivePMAAhollow microspheres with flexible (deformable) shells were obtained after selective removal of the inorganic SiO2 core from the SiO2-PMAA core-shell microspheres by HF etching. The pH-responsive properties of the PMAA hollow microspheres were investigated by dynamic laser scattering (DLS). On the other hand, concentric and rigid hollow silica microspheres
were prepared by selective removal of thePMAAinterlayer from the SiO2-PMAA-SiO2 trilayer hybrid microspheres during calcination. The hybrid composite microspheres, pH-sensitive hollow microspheres, and concentric hollow silica microspheres were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray (EDX) analysis.