## 3 Results and Discussion  
### Enthalpy Change in the \"Multi Walled Carbon Nanotubes-Hydrocarbon Plasticizer\" System  
The calculation of stable dispersion systems containing carbon nanotubes is based on fundamental thermodynamic principles. The change in Gibbs free energy (\(\Delta G\)) is a key indicator determining the possibility of dispersion. If \(\Delta G\) is less than zero, the dispersion process is feasible. Enthalpy (\(\Delta H\)) characterizes the energy of interaction between carbon nanotubes and plasticizer molecules. A positive enthalpy indicates that energy input is required for dispersion. Interfacial tension (\(\gamma_{\text{CP}}\)) determines the ease of dispersion, as lower tension facilitates the separation of nanotubes. To calculate the enthalpy contribution (\(\Delta H\)), which reflects the energy of interaction between carbon nanotubes and hydrocarbon plasticizer molecules, the surface tension in the \"multi-walled carbon nanotubes-hydrocarbon plasticizer\" dispersion system was determined. Optimal ultrasonic dispersion times were established beforehand, during which the minimum average diameters of multi-walled carbon nanotubes were observed in these dispersion systems, as shown in Table 3. The results of surface/interfacial tension measurements at a temperature of 25 \({}^{\circ}\)C are presented in Figure 3.  
Figure 2: Determination of stability during storage of polymer nanomodified binder according to GOST EN 13399-2013. Analysis of the obtained data (Table 3 and Figure 3) shows that for industrial oil I-40A, the surface tension remains constant at 31.4 across all MWCNT concentrations (from 0% to 5\(\cdot\)10\({}^{-2}\)%). This indicates that in this system, MWCNT does not significantly interact with the molecules of industrial oil, which will negatively affect the dispersion and stability of MWCNT in this system. In the dispersion systems with II Vacuum Distillate, Residual Extract, and Distillate Extract, a decrease in surface tension is observed for all MWCNT concentrations, which will promote better interaction with MWCNT and its more uniform distribution during dispersion. This could also potentially have a positive impact on the formation of homogeneous and stable dispersion systems. Figure 3: The effect of the content of MWCNTs on the surface/interfacial tension value in various plasticizers. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Name of Hydrocarbon Plasticizer**} & \multirow{2}{*}{**Content of WCNT, \%**} & \multirow{2}{*}{**Optimal Dispersion Time for**} & **Average MWCNT** \\  & & & **Compositions, min** & **Diameter, \(d_{avg}\), nm** \\ \hline \multirow{3}{*}{Industrial Oil Grade I-40A} & 5\(\cdot\)10\({}^{-4}\) & 3 & 56.27 \\  & 5\(\cdot\)10\({}^{-3}\) & 5 & 57.29 \\  & 5\(\cdot\)10\({}^{-2}\) & – & – \\ \hline \multirow{3}{*}{II Vacuum Distillate} & 5\(\cdot\)10\({}^{-4}\) & 3 & 33.31 \\  & 5\(\cdot\)10\({}^{-3}\) & 4 & 33.41 \\  & 5\(\cdot\)10\({}^{-2}\) & 3 & 34.9 \\ \hline \multirow{3}{*}{Selective Purification Extract, Distillate} & 5\(\cdot\)10\({}^{-4}\) & 2 & 23.58 \\  & 5\(\cdot\)10\({}^{-3}\) & 3 & 23.59 \\  & 5\(\cdot\)10\({}^{-2}\) & 4 & 24.61 \\ \hline \multirow{3}{*}{Selective Purification Extract, Residue} & 5\(\cdot\)10\({}^{-4}\) & 2 & 21.00 \\  & 5\(\cdot\)10\({}^{-3}\) & 3 & 21.00 \\ \cline{1-1}  & 5\(\cdot\)10\({}^{-2}\) & 4 & 21.05 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Optimal ultrasonic dispersion time in dispersion systems. The analysis also revealed that the greatest change in surface tension upon the introduction of MWCNT is observed in the system with the Residual Selective Refining Extract. In this case, the changes ranged from 21.47% (for an MWCNT concentration of 5\(\cdot 10^{-4}\)%) to 37.73% (for an MWCNT concentration of 5\(\cdot 10^{-2}\)%). In the systems with II Vacuum Distillate and Distillate Extract, surface tension changes are approximately at the same level, ranging from 9.4% to 11.07%, respectively.