**4. Conclusions**

Polymer clay nanocomposite (PCN) samples were generated in this study by combining different concentrations of organic clay (1%, 3%, and 5% OC) in toluene solvent and polystyrene as the matrix (OC/PS). Many techniques, including FT-IR, XRD, and TEM, were used to characterize the organoclay and PCN films to ensure the success of the modification procedure. After treating sodium clay (NaC) with CPC, the shifts in the FT-IR spectra confirmed the presence of CPC in the organic clay samples. An exfoliated structure was obtained from the XRD spectrum for low clay loading (1–3% PCN), whereas an intercalated structure was the dominant form for the 5% PCN. The XRD results were confirmed by TEM images. Exfoliated structure preparation is crucial, as it might be employed in polymer clay nanocomposite coating. Furthermore, the electrochemical measurements (EIS, EFM, and Tafel plots) coincide with the morphological data from the XRD and TEM. According to the results of the electrochemical experiments (EIS, EFM, and Tafel plots), commercial Indian clay provides greater corrosion protection than native Khulays clay. This is clearly demonstrated by comparing the corrosion resistance values obtained from the EIS technique, as well as the relative coating efficiencies obtained from the EFM test and Tafel plots of both types of PCNs. The nanocomposite with a concentration of 1% has a fully exfoliated structure and showed stronger protective characteristics than the nanocomposites with partially exfoliated structures (3 wt.% PCN and 5% PCN). This is due to the increased tortuosity of the diffusion paths of oxygen, water molecules, and chloride ions when compared with pure PS coating. Even with a modest amount of clay added, polymer clay nanocomposites exhibit improved coating characteristics. This is due to the clay particles' nanoscale size, which results in a wide contact area between the polymer matrix and filler. The structure of clay, with layers of a high aspect ratio, provides superior barrier characteristics as well as enhanced anticorrosive capabilities. This principal result can be attributed to the chemical composition of commercial Indian clay and the high percentage of the montmorillonite concentration when compared with the local Khulays clay. The high montmorillonite content (64.9%) boosted the ability of this clay to swell more than Khulays clay, which has 35.22% montmorillonite, which increases the tortuous track of corrosive ions. It was discovered that commercial Indian clay has better corrosion protection (81.4%) than local Khulays clay (60.2%). A comparison with other studies using current density values proved that the current density values of our study are much better than those of the best study of Chen-Yang et al. using polyurethan. The current density value of PCN (RCIn) 7.23 × 10−<sup>8</sup> A/cm<sup>2</sup> is better than any other formulation.

**Author Contributions:** Methodology and supervision, L.A.A.J. and W.K.M.; writing—original draft, N.A.H.; reviewing, L.A.A.J. and W.K.M.; revision, H.H.A. All authors have read and agreed to the published version of the manuscript.

**Funding:** The authors extend their appreciation to the Deputyship for Research & Innovation, the Ministry of Education, in Saudi Arabia for funding this research work through project no. IFKSURG-2-480.

**Data Availability Statement:** Not applicable.

**Acknowledgments:** This work is based on the master's thesis of Nashwa A. Howyan, who worked under the supervision of Layla A. Al Juhaiman (corrosion) as the major supervisor, and Waffa K. Mekhamer (polymers) as the assistant supervisor.

**Conflicts of Interest:** The authors declare no conflict of interest.
