Synthesis of new superhydrophobic nanosilica and investigation of their performance in reinforcement of polysiloxane

We reported a new facile method to synthesize superhydrophobic nanosilica using glycidoxypropyltrimethoxysilane and dodecylamine as treatment agents. Also, we systemically investigate their performance in reinforcement of poly(dimethylsiloxane) (PDMS) rubber. Fourier transform infrared spectrum, contact angle (CA) and thermogravimetric analysis (TGA) measurements were used to characterize the modified nanosilica. Results show that the inherent hydrophilicity of parent nanosilica surface can be greatly altered through this modification method. The CA of as-prepared superhydrophobic nanosilica can reach 160.2°. The properties of as-prepared modified nanosilica-filled PDMS composites were systemically investigated by dynamic rheological test, scanning electron microscopy, TGA, dynamic mechanical analysis. These as-prepared superhydrophobic nanosilica exhibit uniform dispersion in the PDMS matrix, and their composites also show good mechanical properties and distinct advantage on thermal stability compared with those of the pure silica-filled PDMS composites. Also described is the probable mechanism for the reinforcement of as-prepared superhydrophobic nanosilica-filled PDMS. POLYM. COMPOS., 31:1628-1636, 2010.