Development of MWCNTs@PDMS nanocomposites with enhanced hydrophobicity and thermo-oxidative stability

This paper presents the fabrication of hydrophobic polymer nanomaterials with improved thermal characteristics based on MWCNTs and poly(dimethylsiloxane). The samples were synthesized by physical adsorption of poly (dimethylsiloxane) onto P-MWCNTs surfaces in the amount from 5 to 20 wt%. The effect of different content of adsorbed polymer on the structure and properties of the prepared nanocomposites was studied in detail using ATR-FTIR, SEM, TEM, XRD and RS techniques. XPS results showed that with the increase of adsorbed PDMS onto the MWCNTs surfaces, the Si 2p atomic percentage increased from 1.5 to 5.0 at. %. The investigation of thermal properties using TGA/DSC techniques in air atmosphere revealed that polymer adsorption on the MWCNTs surfaces enhances the thermo-oxidative stability of the nanocomposites to a great extent. The WCA of MWCNTs@PDMS-1000(20) nanocomposite reached 138.9 degrees while this value was 81.8 degrees in the case of the PMWCNTs. The electrical characterization of the examined samples demonstrated a non-linear current-voltage behaviour and the invariance of the electrical current value with the increasing polymer content in the nanocomposites. The results suggest that the obtained nanocomposites have multi-functional surfaces and are promising for integration into a silicon-based polymer matrix for the development of new materials for electronic devices.