## 2 Results and Discussion
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Polymer \({}^{*}\)** & \multicolumn{6}{c}{**Reaction Time, Hours**} \\ \cline{2-7}  & \multicolumn{2}{c}{**3**} & \multicolumn{2}{c}{**5**} & \multicolumn{2}{c}{**11**} \\ \cline{2-7}  & \(S\)** & **n\({}_{\text{red}}\)** & **s\({}^{**}\)** & **n\({}_{\text{red}}\)** & **s\({}^{**}\)** & **n\({}_{\text{red}}\)** & **n\({}_{\text{red}}\)** & **n\({}_{\text{red}}\)** \\  & **wt.\%** & **dL/g** & **wt.\%** & **dL/g** & **wt.\%** & **dL/g** \\ \hline SPNBI-I,III **** & 0.6 & - & 2.1 & - & 5.9 & 0.4 \\ SPNBI-II,III & 1.1 & 0.1 & 2.5 & 0.2 & 4.8 & 0.2 \\ SPNBI-II,IV & 1.7 & 0.1 & 2.7 & 0.2 & 6.3 & 0.3 \\ \hline \hline \end{tabular}  
* The starting materials for synthesis correspond to those given in Scheme 3. ** Sulfur content according to elemental analysis, wt.%. *** Reduced viscosity \(\eta_{\text{red}}\), measured in N-methylpyrrolidone (N-MP) at 25 \({}^{\circ}\)C, at a concentration of 0.5 g/dL. **** Partially soluble in N-MP.  
\end{table} 
Table 1: One-step synthesis conditions and properties of sulfonated polynaphthoylenebenzimidazoles. The data of elemental analysis, the reduced viscosity, and IR spectroscopy indicate that under the conditions used (sulfuric acid:oleum 3:1, 120 \({}^{\circ}\)C), the cyclopolycondensation between bis-naphthalnic anhydrides and tetraamines and sulfonation of the resulting polymers occur simultaneously, leading to the formation of functional SPNBIs. SPNBI-I,III was chosen for electrophysical studies in terms of biosensing applications and obtaining of solid ionomers, because of its limited solubility in N-MP and the highest reduced viscosity. At the same time, it contains a high amount of sulfur. Salts based on SPNBI-I,III were prepared under heterogeneous conditions as described in the Materials and Methods section. Figure 1: Solid-state \({}^{13}\)C NMR spectra for synthesized polymers. Figure 2: \({}^{13}\)C NMR spectrum for SPNBI-I,III in D\({}_{2}\)SO\({}_{4}\). TGA curves for all three SPNBIs synthesized (1-3) and K (4), Ca (5), and Cr (6) salts of SPNBI-I,III are given in Figure 3. All SPNBIs absorb moisture from the air, and the low-temperature part of the mass loss curves corresponds to its removal (Figure 3, curves 1-3). At higher temperatures of 350-400 \({}^{\circ}\)C, another mass loss region was observed on TGA curves of SPNBIs. As it was shown earlier [22], it is associated with desulfurization process with the formation of intermolecular -SO\({}_{2}\)-bridging bonds. On the TGA curves of the ionomers (Figure 3, curves 4-6), a similar decomposition region is absent, which indicates the completion of the process of hydrogen replacement in the sulfo groups for metal atoms. The thermal stability of salts decreases in the cation series K > Ca > Cr, which is related to an increase in ionic radius of metal cation from potassium to calcium and then to chromium and, as a consequence, to the effect on the decomposition of the polymer salts of SPNBI-I,III. A similar pattern was observed earlier for polyphenylquinoxalines salts with alkali metals [23]. To prepare polymer coatings on quartz crystal microbalance sensors, we used electron beam dispersion of solid polymers in vacuum (EBD) [24]. This method enables to obtain the coatings on various substrates with high adhesion and developed surface, which is necessary for sensor applications [25,26]. It should be noted that EBD allows obtaining more stable coatings than coatings obtained by aerosol method or by the dip coating or spin coating methods [10,14,27]. The properties of polymer coatings, obtained by EBD method, depend on the molecular structure of solid polymers, which are irradiated by electron beam. Electron beam heats the surface of solid polymer in vacuum and decomposes it as a result. The molecular and nanosized fragments emitted from the target polymer form the coating on the substrate surface. According to TGA data given in Figure 3, the thermal stability of various SPNBIs and the salts is different.