The final weight-loss ratio of PAA-KH550 polymer was about 95% in the end. Comparing

the five traces, the weight fraction of PAA-KH550 polymer on siloxane-GNPs and that of SiO2 on SiO2/GNPs hybrid material could be estimated by following equations [19]: (1) (2) Figure 4 TGA curve selleck kinase inhibitor spectrum diagram. (curve a) SiO2, (curve b) f-GNPs, (curve c) SiO2/GNPs hybrid material, (curve d) siloxane-GNPs, and (curve e) PAA-KH550. where A%, B%, C%, D%, and E% were the weight loss percentages at a certain selleck temperature of f-GNPs, SiO2/GNPs hybrid material, siloxane-GNPs, PAA-KH550, and SiO2, respectively. X and Y were denoted as the weight fraction of polymeric species on siloxane-GNPs and content of SiO2 on SiO2/GNPs hybrid material, respectively. According to our calculation, At 900°C, the residual weight fraction of polymer on siloxane-GNPs was about 94.2% and that of SiO2 particles on hybrid materials was about 75.0%. Scanning electron microscopy Figure  5 presented the SEM micrographs of the morphology of various GNPs samples. f-GNPs in lateral dimension were shown in Figure  5a, which

were crumpled due to the Selleck Erismodegib transformation from a planar sp2-hybridized to a distorted sp3-hybridized geometry during the oxidation process. As shown in Figure  5b, after reacted with PAA, the sheet of GNPs appeared thicker in its thickness. Figure  5c showed micrographs of siloxane-GNPs. There appeared polymer on the surface of GNPs because of reacting with KH550. As showed in Figure  5d, SiO2 particles were adsorbed on surface of f-GNPs nanosheets. From all the images and analysis above, it was reasonable to believe that SiO2 particles have grown on the surface of GNPs successfully. Figure 5 SEM images of (a) f-GNPs, (b) PAA-GNPs, (c) siloxane-GNPs

and (d) SiO 2 /GNPs. Transmission electron microscopy The typical morphologies of all samples were observed with TEM. As shown in Figure  6a, the surface of f-GNPs was relatively smooth and clean. After being functionalized with PAA, the surface of GNPs became blurred as shown in Figure  6b. After reacted with KH550, the functionalized GNPs (Figure  6c) became thickened and there appeared tubes on the surface of GNPs. The typical morphologies during of SiO2/GNPs hybrid material were showed in Figure  6d. It was clear to discern that the SiO2 particles were hanged on the surface of f-GNPs. And the diameter of SiO2 varies from 100 to 200 nm. The TEM images were consistent with the result of the SEM, which confirmed that our route of preparing SiO2/GNPs hybrid material was reasonable. Figure 6 TEM images of (a) f-GNPs, (b) PAA-GNPs, (c) siloxane-GNPs, and (d) SiO 2 /GNPs hybrid material. Figure  7 depicted the whole growth process of SiO2 particles on the surface of graphene with the ammonia of 1.2 g and TEOS of 0.6 g.