## 3 Results and Discussion
### Structural Characterization  
FTIR SpectroscopyFTIR spectra of the nanoparticles were obtained by dispersing the sample in anhydrous potassium bromide. For PSTFSILi, the peak at 1000-1400 cm\({}^{-1}\) corresponded to the stretching of the C-F bond. The broad peaks in the range of 1350-1300 cm\({}^{-1}\) (s) and 1180-1140 cm\({}^{-1}\) (s) were due to the O\({}_{2}\)S-N-bond. For PSPRSILi, strong peaks around 3063.53 cm\({}^{-1}\) corresponded to aromatic C-H stretching and 1500-1400 cm\({}^{-1}\) related to aromatic C=C stretching. The peak around 1630 cm\({}^{-1}\) represents the S-N-S combination bond, which indicates that the reaction was complete. For PSDTTOLi, after lithiation of PSDTTO, the peak at 1717.43 cm\({}^{-1}\) shifted to 1705.73 cm\({}^{-1}\), and 1639.34 cm\({}^{-1}\) shifted to 1637.34 cm\({}^{-1}\), which can be assigned to the stretching vibration band of carbon with the existence of three sulfone electron withdrawing groups. These data partially support the proposed structures of the lithium bound polymer salts.  
Energy Dispersive X-ray SpectroscopyThis technique for elemental analysis was performed with a scanning electron microscope (SEM, Phenom Pro-X, Nanoscience Instruments) by selecting three different mapping areas in the secondary electron mode with an acceleration voltage of 15 kV. All samples were deposited on a silicon wafer for SEM/EDS measurement after they were dispersed in pure ethyl alcohol and sonicated for 1 h. EDS measurement of each mapping area took about seven minutes, so the total collecting time was 21 min for the three different mapping areas to obtain better statistics or consistency. Figures 4-6 show the EDS elemental composition of each sample, while the obtained elemental concentrations from the EDS studies are presented in Table 1. The analysis of the data indicates that all of these salts had a different ratio of carbon, nitrogen, oxygen, and sulfur, while only PSTFSILi exhibited 8.2% F. Lithium ions were too small to be detected by the instrument.  
Figure 3: Synthesis of PSDTTOLi.  
Figure 2: Synthesis of PSPHSILi.  
_Scanning Electron Microscopy:_ The morphology of the PS-bound lithium salt nanoparticles was analyzed using scanning electron microscopy (SEM) (Leica, Cambridge, UK) with an accelerating voltage value equal to 15 kV. The samples were coated with a thin gold layer using a sputter coater  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Sample** & **At. \% C** & **At \% N** & **At. \% O** & **At. \% S** & **At. \% F** \\ \hline PSTFSILi & 48.9 & 13.5 & 26.4 & 3.1 & 8.2 \\ PSPHSILi & 58.4 & 5.7 & 26.2 & 9.7 & - \\ PSDTTOLi & 40.4 & - & 26.9 & 26.9 & - \\ \hline \hline \end{tabular}
\end{table}
Table 1: Elemental concentrations determined using the energy dispersive X-ray spectroscopy (EDS).  
Figure 4: Energy dispersive X-ray spectroscopy (EDS) of the PSTFSILi nanoparticles.  
Figure 5: Energy dispersive X-ray spectroscopy (EDS) of the PSPHSILi nanoparticles.  
Figure 6: Energy dispersive X-ray spectroscopy (EDS) of the PSDTTOLi nanoparticles.  
(Polaron, model SC502, Williston, VT, USA) [13]. TFSI and PhSI modified nanoparticles displayed similar particle sizes at around 500 nm, whereas the DTTO modified nanoparticles measured at around 350 nm (Figure 7). In either case, the particle size was much larger that the starting PS nanoparticles (50 nm). This indicates that PS particles agglomerated during the incorporation of functional groups [24].