Facile Modification of Surface of Silica Particles with Organosilanepolyol and Their Characterization

Abstract

The surface modification of silica particles (SPs) was systemically conducted by the treatment of 0.1-10 wt % phenylsilanetriol (PST) on the basis of SPs used through two step processes: 1) the PST coating of SPs via evaporation under reduced pressure and 2) their thermal condensation leading to Si-O-Si bond formation via heating at 130°C. The evaluation of the modified SPs was conducted by the simple floating test on water and the measurement of the contact angle (CA) of water droplet on the 2-dimensional layer of modified SPs on slide glass. When PST was used about 2 wt % or above on the basis of SPs (about average size: 50 nm) used, the modified SPs were fully floated on the water and all dispersed into upper organic solvent layer after a shaking with the mixture of the water and benzene, indicating that the modified SPs have hydrophobic properties. The modified SPs were characterized by 29Si MAS NMR and physicochemical properties including SEM, TEM, BET, adsorption/desorption isotherms, etc. were measured and compared each other in details. This research demonstrates that the organosilanetriol is a good modifier applicable for the surface modification of inorganic oxide particles using a low amount of modifier on the basis of oxide particles used.

In Situ Formation of Silica Nanoparticles Decorated with Well-Defined Homopolymers and Block Copolymers

“…Several factors impact the property enhancement of nanocomposites: − (i) the interaction of the matrix with the nanofillers’ surfaces, (ii) their dispersion within the matrix, (iii) the nanofiller content, and (iv) the nanofiller type. Among various nanofillers, the most widely used for the production of polymer nanocomposites are carbon nanotubes, titanium dioxide (TiO 2 ), zinc dioxide (ZnO 2 ), calcium carbonate (CaCO 3 ), silica (SiO 2 ) nanoparticles (NPs), and nanoclays. ,− In particular, polymer/silica nanocomposites have attracted tremendous academic/industrial interest and have been used in various applications. , Thanks to their excellent mechanical properties and thermal stability, SiO 2 NPs have been used with hydrophobic polymeric materials, such as polyolefins, to improve their properties. ,, However, pristine SiO 2 NPs aggregate at the matrix interface, thus preventing uniform dispersion and maximum property’s benefits. ,− By modifying SiO 2 NPs with small organic molecules, using silane coupling agents, hydrophobic fillers compatible with polymer matrix were produced. − Moreover, the ability of grafted polymer chains to fully cover the surface helps the SiO 2 NPs to homogeneously be dispersed in the matrix, since the matrix does not “see” the NPs but only the grafted chains.…”