Synthesis and characterization of PDMS-grafted graphite oxide sheets

For the first time, polydimethylsiloxane (PDMS) was grafted onto graphite oxide sheets through two routes. The grafting reactions were performed in toluene as solvent via a hydrosilylation reaction and a hydrolysis condensation reaction in presence of SiH-terminated PDMS and ethoxysilane-terminated PDMS, respectively. Dispersion of PDMS coated graphite oxide in a PDMS oil was utilized to follow the introduction of PDMS onto the GO sheet surface while X-ray photoelectron spectroscopy and thermogravimetric analysis indicated the extent of this grafting. The grafting densities were found to vary from 0.7 × 10−3 mmol g−1 to 12.7 × 10−3 mmol g−1 depending on the PDMS molar mass. It was found that a higher level of grafting was obtained using a hydrosilylation reaction with low molar mass SiH-terminated PDMS rather than a sol–gel process with the use of ethoxysilane-terminated PDMS.