## 3 Results and Discussion
### Effect of CNT Types and CNT Concentrations on Suspension Polymerization of Styrene and nBA
Although ethanol and acetone are both polar solvents, they exhibit varying dielectric constants and hydrogen-bonding capabilities [46], so different solubility properties are to be expected. Ethanol dissolves MEP-51 better because it improves solubility and hydrophobic material dispersion through its ability to disrupt intermolecular forces and solvate the surfaces of the particles. The observed lower conversion rate of MEP-51 in acetone than in ethanol thus stems from acetone's inability to adequately dissolve the monomer. After selecting the solvent, the effect of MEP-51 concentrations on conversion and particle size was investigated. MEP-51 is a common CCA used in toner formulations to control the electrical charge of toner particles, which is necessary for proper printing. MEP-51 CCA is a quaternary ammonium compound that contains a long hydrocarbon chain, and its chemical structure allows it to adsorb onto the surface of toner particles, creating a negative charge. This negative charge helps to stabilize the toner particles and prevent them from clumping together. MEP-51 CCA can also help increase the toner's sensitivity to magnetic fields, which is necessary for proper printing. As shown in Table 9 and Figure 5, the conversions were 90% or greater for all concentrations below 0.28 wt% (for the highest concentration, 0.42 wt%, the conversion was 28 wt%, which needs to be further investigated). This is in contrast to the findings for MEC-88. Simply put, greater MEP-51 concentrations resulted in higher conversion rates, with the two directly proportional, while the MEC-88 concentrations were inversely proportional to the conversion rates. This difference stems from the differences in their respective chemical characteristics: MEC-88 has carbonyl groups that have a retarding/inhibiting effect when suspension polymerization occurs, while MEP-51 lacks a carbonyl functional group, as shown in Figure 6.  
According to [PERSON] et al. (2018), the conversion of styrene and nBA (the same monomers as used in the present work) was not more than 80% in all cases in which carbon black (CB) was used as a pigment; the conversion decreased with greater CB concentrations. In contrast, in the present study, when CNTs were used, the conversion was found to be over 90%--more than 10% greater than with CB. This shows the advantages of using CNTs as a pigment instead of CB, which has never been reported before. Other advantages of using CNTs include the particle size of the toner materials: when it is small (of nm scale), the particles are undesirable because they can be harmful or unhealthy. The current study  
Figure 5: Monomer conversion versus MEP-51 concentration. Figure 6: Chemical character of MEP-51. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Sample Code**} & **CCA** & **CCA** & **CNT-D** & **CNT-D** & **Conversion** & \multicolumn{2}{c}{**DLS Measurement**} \\  & **Con. (g)** & **wt.\%** & **Con. (g)** & **wt.\%** & **(\%)** & **Z-Average** & **PDI** \\ \hline SP-CNT-D-MEP-51-1 & 0.102 & 0.42 & 0.034 & 0.14 & 28 & 2106 & 1.00 \\ SP-CNT-D-MEP-51-2 & 0.068 & 0.28 & 0.034 & 0.14 & 91 & 6793 & 0.226 \\ SP-CNT-D-MEP-51-3 & 0.034 & 0.14 & 0.034 & 0.14 & 90 & 5251 & 0.146 \\ SP-CNT-D-MEP-51-4 & 0.017 & 0.07 & 0.034 & 0.14 & 93 & 5784 & 0.217 \\ SP-CNT-D-MEP-51-5 & 0.011 & 0.05 & 0.034 & 0.14 & 97 & 5882 & 0.161 \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Suspension polymerization of styrene and butyl acrylate in the presence of CNT-D and five different concentrations of MEP-51. sought to develop new materials for a less harmful and more environmentally friendly toner, so the polymerized particle sizes for the toner materials were measurable in microns (see Figure 7).