Application of tailored silica microspheres in coatings: synthesis, characterization, thermal and hydrophobic properties

Tailored silica microspheres were synthesized using CTAB as a soft template, e.g. solid, mesoporous silica microspheres, solid silica core/mesoporous silica shell (sSiO2@mSiO2) microspheres and hollow silica microspheres. The prepared samples were characterized by SEM, TEM, XRD, and BET. The mechanism of morphological evolution was also proposed based on the experimental results, which reveals the formation processes of solid, mesoporous silica microspheres, solid silica core/mesoporous silica shell (sSiO2@mSiO2) microspheres and hollow silica microspheres. Then silica/silicon resin coatings consisting of the four representative silica particles were prepared. The corresponding FT-IR, UV-Vis spectra and surface water wettability test showed better performance for coatings comprised of the other three silica particles than that of solid SiO2 microspheres. Coatings comprised of mesoporous SiO2 had the best performance of heat insulation and heat preservation and hydrophobic property. The top-view and cross-sectional SEM images and the AFM images of the coatings were also analyzed to explain the relationship between factors such as surface morphology, film thickness, surface roughness of the coating and its related properties.