Thus, the area ratio of D band to G band (ID/IG) indicates that structure quality. It was obvious that the MWCNTs/GnPs hybrid materials had the lowest ratio (0.3051) compared to MWCNTs-OH (0.8435), MWCNT-PACl (0.7254), and GnPs-OH (0.3653). The change on the ratio

of ID/IG meant that a higher defect level was caused by the grafting the polymer chain Ixazomib molecular weight onto the wide surface area of graphene as well as to the passivation of dangling bonds onto the surface of the MWCNTs [18]. Figure 5 Raman spectra images. (a) MWCNTs-OH. (b) MWCNTs-PACl. (c) GnPs-OH. (d) MWCNTs/GnPs hybrid materials. In addition, it should be noted that the G band of MWCNTs was divided into two bands, and the new D′ band at 1,604 cm−1 could be related to the extent

of the disorder [19, 20]. It was worth noting that the D′ band was hardly observed for other samples, which indicated that GnPs and hybrid materials have the smallest amount of impurities. Consequently, the hybrid materials possess higher mechanical properties and thermal conductivity with high crystalline structures [11, 21]. Thermal gravimetric analysis Figure 6 showed the thermogravimetric curves for various samples. The weight-loss behavior of MWCNTs/GnPs (Figure 6c) and MWCNTs-PACl (Figure 6d) could be explained in comparison with those of GnPs-OH (Figure 6a), MWCNTs-OH (Figure 6b), and PACl (Figure 6e). Under N2 atmosphere, the GnPs-OH (Figure 6a) and MWCNTs-OH GSI-IX (Figure 6b) showed a slight weight loss owing to the removal of the hydroxyl groups generated by the acid treatment [13]. Neat PACl (Figure 6e) lost about 97% of its original weight before 600°C, and there were two identified stages. The weight loss between 200°C and 300°C was assigned to the decomposition of the side groups of PACl, and the weight loss between 320°C and 550°C was likely due eltoprazine to the decomposition of the polymer backbone. Similarly, the curves for MWCNTs-PACl (Figure 6d) and MWCNTs/GnPs hybrid materials (Figure 6c) almost coincided with the curves of the neat PACl underwent a two-stage weight reduction in the same temperature regions. As shown in Figure 6c, besides the weight loss of PACl occurring at about 400°C, the initial

weight loss after 500°C resulted from the presence of GnPs-OH. By referring to the formula in [22], we calculated that the residual weight fraction of polymer on MWCNTs-PACl was about 72% and that of GN-OH on hybrid was about 11% at 600°C. From characterization results of TGA, TEM, and SEM, the covalent linkage of PACl molecules on the surface of MWCNTs and GnPs was confirmed [23]. Figure 6 TG curves. (a) GnPs-OH. (b) MWCNTs-OH. (c) MWCNTs/GnPs hybrid materials. (d) MWCNTs-PACl. (e) PACl. Conclusions In summary, MWCNTs/GnPs hybrid materials can be successfully obtained by a facile method using PACl as a bridge. MWCNTs were assembled onto the surface of GnPs through the reaction of the hydroxyl groups of GnPs and the acyl chloride groups of PACl.