Comparing FGO-DDA/PS with pristine PS, all of the peaks from the FGO-DDA/PS composite have lower intensities, and the -CONH-

peak appeared in the same region as FGO-DDA [22], which prove that FGO-DDA was associated with the PS matrix. Figure 1 FT-IR spectra of GO, FGO-DDA, FGO-DDA/PS composites, and neat PS. The elemental analysis was check details further used to confirm the covalent functionalization of GO with DDA. The N contents Syk inhibitor were determined to be 3.07, 3.17, 3.21, and 3.21 wt.% for reaction times of 6, 12, 18, and 24 h, respectively, while the Cgraphene/O ratios were in the range of 2.01 to 2.43. After 12 h of reaction, the Cgraphene/N ratio tended to saturate around 12.5, corresponding to one DDA molecule per six aromatic rings on the GO sheet. Cross-sectional images of freshly fractured pristine PS and FGO/PS composites were observed using SEM (Figure 2a,b,c,d,e). As shown in Figure 2a,b, even with a small amount of FGO, the FGO/PS composite exhibited noticeably increased wrinkles compared to pristine

PS. As the FGO content increased, the wrinkles became finer, which indicates a strong interaction KU-57788 mw between FGO and PS. It is interesting to note that all of the FGOs were homogeneously dispersed onto the PS matrix even at high loading (10 wt.%). When the chain length of the alkyl group of the FGOs was increased, the wrinkles of the FGO/PS composite became larger and wider (Figure 2d,e), which can be attributed to the effect of the increased aspect ratio of the alkylamines

[23].The dispersions obtained at a 10 wt.% loading of the FGOs over PS composites were also observed by TEM (Figure 2f,g,h). Because the FGOs are compatible with the PS matrix, the FGO sheets were uniformly dispersed on the PS matrix, which is consistent with the SEM images. Notably, Vorinostat solubility dmso FGO-OA/PS showed a broad, plate-type dispersion on the transparent PS film, whereas FGO with a long length alkyl chain had a tiny droplet form on the PS film. Figure 2 Dispersion properties of FGO on PS. FE-SEM images of neat PS and the FGO/PS nanocomposites: (a) neat PS, (b) 1 wt.% FGO-OA/PS, (c) 3 wt.% FGO-OA/PS, (d) 10 wt.% FGO-OA/PS, and (e) 10 wt.% FGO-HDA/PS. TEM images of 10 wt.% (f) FGO-OA/PS, (g) FGO-DDA/PS, and (h) FGO-HDA/PS. TGA analyses were performed to investigate the thermal properties of the FGO/PS composites and pristine PS. In the thermal stabilities of FGOs (Figure 3a), the main mass loss occurred from 200°C to 500°C due to the decomposition of the alkylamine moiety [18]. The mass residues of the FGOs decreased with increased alkylamine length, from 60 wt.% for FGO-OA to 43 wt.% for FGO-DDA and 34 wt.% for FGO-HDA at 500°C.