## 3 Results and Discussion
This morphological feature is a strong indication of the Pickering effect. Dielectric properties of several composite materials were investigated by Electrical Impedance Spectroscopy (ESI). Nyquist Plots (Z' vs. -Z\" plots), Impedance vs. frequency, and Phase shift vs. frequency plots, also known as Bode Plots, are reported in Figure 4 for the following porous monoliths: HCPEG (Figure 4a,b), HCPEG\(-\)GNWs (0.4% wt) (Figure 4c,d), HCPEG\(-\)PANI (0.8% wt) (Figure 4e,f), and HCPEG\(-\)PANI (0.8% wt)\(-\)GNWs (0.4% wt) (Figure 4g,h). All the monoliths showed two characteristic time constants (\(\tau_{1}\) and \(\tau_{2}\), two distorted semi-circles in the Nyquist plots) indicating the existence of two dipole relaxation processes. Nyquist plots showed a certain degree of distortion indicating that the frequency-dependent impedance cannot be interpreted in terms of ideal circuit elements in an equivalent circuit. Besides, we may tentatively ascribe these two processes to the dipole relaxation of the polymer matrix and porosity respectively, but it is difficult, if not impossible, to derive physical parameters like a chemical capacity, a double layer capacity, or a resistance which can be linked either to one phase or the other just by fitting an equivalent circuit. These physical parameters are lumped and cannot be derived directly. Surely, both fillers (PANI and GNWs) had a profound impact on the time constants \(\tau_{1}\) and \(\tau_{2}\) by decreasing their values which means faster dipole relaxation processes. Bode plots of porous monolithic HCPEG and HCPEG\(-\)GNWs (0.4% wt) (Figure 4b,d) showed high impedance at low frequency at about \(-90\) phase angle (\(\phi\)), clearly indicating a capacitive behaviour. When the frequency increased, the phase angle (\(\phi\)) dropped to around \(-20\) and \(-12\) phase angle (\(\phi\)) which was at around 1.9 Hz and 5.2 Hz, respectively, then it started increasing again. This suggests the occurrence of a transition from capacitive to a resistive behaviour via a dipole relaxation at those frequencies. By adding GNWs to the porous phase the resonance of this dipole relaxation shifted towards a higher frequency. Owing to that GNWs uniquely fill the porosity, one may claim that this dipole relaxation was mainly associated with the porosity. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Specimen** & **avg. Diameter, \(\mu\)m** & **s.d.** \\ \hline HCPEG & 0.77 & 2.21 \\ HCPEG + GNW(0.4\% wt) & 0.25 & 0.56 \\ HCPEG + PANI(0.01\% wt) & 1.69 & 2.16 \\ HCPEG + PANI(0.05\% wt) & 2.11 & 2.79 \\ HCPEG + PANI(0.1\% wt) & 2.36 & 3.07 \\ HCPEG + PANI(0.8\% wt) & 3.16 & 4.25 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Average pores sizes and standard deviations of the several materials (avg. stands for average, s.d. for standard deviation). When it comes to the HCPEG\(-\)PANI (0.8% wt), two resonances at low and at high frequencies were noticed (0.04 and 372 Hz, Figure 4e,f). Being PANI the most abundant filler, the evidence that it affected the dielectric properties, to a major extent compared to the sole GNWs, was expected. The high-frequency dipole relaxation resonance was likely due mainly to the PANI, which filled the HCPEG matrix. Moreover, to some extent, it also influenced the dipole dielectric relaxation due to the pores. In HCPEG\(-\)PANI (0.8% wt)\(-\)GNWs (0.4% wt) (Figure 4g,h) the low-frequency resonance almost faded away. This can be explained by invoking some sort of synergic effect where PANI and GNWs together furtherly shift this dipole relaxation towards lower frequencies, beyond the frequency range of the ESI analysis. Notably, the Nyquist plot for HCPEG\(-\)PANI (0.8% wt)\(-\)GNWs (0.4% wt) showed a low frequency hook ending in the positive Z\" quadrant (Figure 4g,h red marks). A positive phase angle impedance indicates that current lags voltage in the frequency range.