## 3 Results and Discussion
### Effect of CNT Types and CNT Concentrations on Suspension Polymerization of Styrene and nBA
This interaction could explain the decrease in the conversion rate observed with increased MEC-88 concentrations in the current study. The findings show that obtaining a high conversion of monomers in the presence of MEC-88, regardless of the CCA improving the charging characteristics of the toner, is not possible; hence, there is a trade-off when increasing MEC-88 concentrations between the conversion rate and achieving desirable electrical conductivity and toner charging characteristics. As this research shows, suspension polymerization of nBA and styrene in the presence of CNT-D and CCA improves the electrical conductivity and charging characteristics of the resulting toners but produces a low conversion rate in return. The SEM micrographs presented in Figure 4 provide insights into why MEC-88 is not desirable for conversion into toner materials. Although the polymerized particles were in the micron range, the SEM micrographs show that they were not uniform, which is in agreement with the DLS results. Nonuniform particles also resulted in poor flowability, uneven charging, and reduced image quality, which are critical properties for toners. CCAs with positively  
Figure 3: Chemical character of MEC-88. Figure 2: Monomer conversion versus MEC-88 concentration for St and nBA. charged surfaces and without carbonyl groups acting like positively charged metal oxides have been shown to solve issues regarding particle size and conversion [3; 42; 43]. SEM photographs of raw materials and polymerized toner can be found in the Supplementary Materials, Figures S1-S4. Figure 4: SEM micrographs of suspension polymerization of St and nBA in the presence of CNT-D and different concentrations of MEC-88: (**a**) SP-CNT-D-MEC-88-5; (**b**) SP-CNT-D-MEC88-4; (**c**) SP-CNT-D-MEC88-3; (**d**) SP-CNT-D-MEC88-2; and (**e**) SP-CNT-D-MEC88-1. The magnifications are 500\(\times\) (scale bar = 50 \(\upmu\)m) and 100\(\times\) (scale bar = 100 \(\upmu\)m). Suspension Polymerization of Styrene and nBA in the Presence of CNT-D and MEP-51 in Different Concentrations  
After obtaining unsatisfactory production of the materials for the toner using MEC-88, another attempt was made with MEP-51 (CCA type, principally positively charged, and no carbonyl group) to determine whether it could solve the retarding/inhibiting limitations of MEC-88. MEP-51 was chosen because of its role in improving toner properties, such as better transfer efficiency, reduced toner scatter, and higher print quality, by promoting the aggregation of toner particles and reducing their surface charge [44]. However, the main concern was determining the effect of MEP-51 on the conversion rate during toner production. As mentioned earlier, MEP-51 is soluble in neither styrene nor water, so it was first dissolved in acetone/ethanol in different amounts before being mixed with water (the water acting as a continuous phase containing PVA, SDS, and dispersed CNT-D). When acetone was used, as mentioned in the experimental section, conversion of more than 45% was not achievable, and the greatest conversion was reached when the least amount of acetone was used. Previous studies indicate that CNT dispersion in acetone is not as good as its dispersion in water, so this result was expected because acetone is a polar aprotic solvent, implying that it has a low dielectric constant and cannot form hydrogen bonds. In contrast, water is a polar protic solvent, meaning that it can readily form hydrogen bonds. CNTs have hydrophobic surfaces because of sp\({}^{2}\) hybridized carbon atoms [45], so they tend to aggregate in aqueous solutions. The difference in solubility of MEP-51 in water and acetone therefore impacts the reaction's outcome, and acetone was thus found to be an unsuitable solvent for the conversion of monomers or the dispersion of CNT-D. However, using ethanol in different amounts instead of acetone produced a promising conversion of 90% when a small amount (5 mL) of ethanol was used, so it was chosen as the solvent for dissolving MEP-51 before polymerization.