## 3 Effect of Surfactants on Mechanico-Thermal Properties
### Effect of Non-Ionic Surfactants  
Table 6 shows the mechanico-thermal properties of polymer nanocomposites modified by non-ionic surfactants. Pluronic (chemical structure showed in Figure 2a) could modify organic nanofillers like CNWs and modified CNWs have been used for the preparation of CNW/DGEBA nanocomposites [7]. The modification of CNWs has improved the mechanico-thermal properties of the nanocomposites. The mechanical properties, such as tensile strength, tensile modulus, and elongation at break, of the nanocomposites have increased by up to 79%, 27%, and 77%, respectively, compared to the unmodified CNW/DGEBA nanocomposite. This is attributed to the improved dispersion and enhanced \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Surfactant** & **Type of Surfactant** & **Nanofiller** & **Type of Nanofiller** & **Modification Method** & **References** \\ \hline Triton X-100 & Non-ionic & CNTs & Inorganic & Ultrasonication & [24] \\ Ultraric PE 105 & Non-ionic & NCFs & Organic & Stirring & [19] \\ SDS & Anionic & G NPs & Inorganic & Ultrasonication & [21] \\ Beycostat A B09 & Anionic & CNCs & Organic & Stirring & [18] \\ DDAB & Cationic & MMT & Inorganic & Aglitation & [12] \\ HTAB & Cationic & CNCs & Organic & Stirring & [31] \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Types of surfactants, types of nanofillers, and modification methods for the preparation of polymer nanocomposites. Figure 1: Chemical structures of (**a**) Triton X-100, (**b**) SDS, and (**c**) DDAB. interfacial interaction between the Pluronic-modified CNWs and the DGEBA matrix [7]. However, the degradation temperature of the nanocomposites decreased because of the presence of small aggregates of Pluronic-modified CNWs in the nanocomposites, which degraded easily in comparison with the large agglomerates. Furthermore, the glass transition temperature of the nanocomposites also decreased due to possible Pluronic micelle formation inside the DGEBA matrix [7]. bonding [10]; both interactions improved the wettability and reduced surface tension of the CNTs in the nanocomposites. Moreover, the glass transition temperature and melting temperature increased by up to 1.0% and 0.6%, respectively, which was also because of the improved interfacial interaction between the Triton X-100-modified CNTs and the PBO matrix, as well as the improved degree of dispersion of the modified CNTs in the nanocomposites [10]. AK8805 could modify inorganic nanofillers like CNFs and the modified CNFs have been used for the preparation of CNF/DGEBA nanocomposites [5]. The modification of CNFs improved the mechanico-thermal properties of the nanocomposites. The mechanical properties, such as tensile strength, tensile modulus, and impact strength, of the nanocomposites increased by up to 20%, 165%, and 15%, respectively, compared to the neat DGEBA, which was due to enhancement of the interaction between the modified CNFs and the DGEBA matrix [5]. Furthermore, the degradation temperature and glass transition temperature of the nanocomposites also increased by up to 4.5% and 2.7%, respectively, because of the better dispersion of CNFs caused by the enhanced interaction [5]. Triton X-100 could also modify inorganic nanofillers such as G NPs and modified G NPs have been utilized for the preparation of G NP/SR nanocomposites [11]. The modification of G NPs improved the tensile strength, tensile modulus, and elongation at break by up to 20%, 5.4%, and 22%, respectively. This is attributed to the capability of the surfactant to act as a bridge between the G NPs and the SR matrix, which subsequently improved the compatibility and wettability of the graphene platelets and this provided a good adhesion to the SR [11]. The maximum degradation temperature of the nanocomposites also improved by up to 3.0% due to the good Triton X-100-G NP/SR interface interaction that offered a better barrier effect [11].