Effect of inorganic-organic composite coating on the dispersion of silicon carbide nanoparticles in non-aqueous medium

In order to disperse silicon carbide (SiC) nanoparticles homogeneously in a non-aqueous medium, the surface of SiC nanoparticles needs to be modified via surface organic functionalization. A method of SiC nanoparticle surface modification by grafting of polyacetals via inorganic-organic composite coating was developed. The resulting graft percentage of up to 10.5% was much higher than that of direct grafting. The inorganic-organic composite coating on a SiC nanoparticle surface led to an almost complete decomposition of the secondary structure of the agglomerates and the formation of the primary structure. Dispersibility of the modified version was studied by using a transmission electron microscope (TEM) and size distribution analyser. The sedimentation experiments showed that the coated SiC nanoparticles exhibited good suspension stability in butanone. The composition of the inorganic-organic composite coating on the SiC nanoparticles was investigated by energy dispersive x-ray analyses (EDX), hydrogen nuclear magnetic resonance (H-1 NMR) and Fourier-transformed infrared spectroscopy (FT-IR). This work provides a novel concept of surface grafting modification for non-oxide nanoparticles to improve their dispersibility in non-aqueous medium.