Production and Characterization of Ag-Doped Multilayer Polyaniline Thin Films by Sol- Gel Method

Abstract

Recently, studies on thin films have attracted increasing attention from scientists. Polyaniline thin films (PANI), which are among the thin films, are preferred for various applications due to their electrical conductivity, environmental stability, thermal stability and doping properties. PANI are used in many areas including supercapacitors, sensors, electronic devices, drug delivery systems. In this study, monolayer,  five-layer, Ag-doped, and HCI-doped PANI thin films were synthesized by sol-gel method and coated on glass substrate via spin coating technique. The chemical, electrical, and morphological properties of glass substrates coated with polyaniline thin film were investigated. The effects of layer number and Ag addition on the characteristics of the PANI thin films were evaluated. SEM analysis revealed that PANI thin films possess a porous structure, and Ag doping improves surface homogeneity. SEM analysis proved that PANI thin films have a porous structure and Ag doping improves the surface morphology. Current–voltage (I–V) measurements were performed to determine the electrical properties of the films. The results showed that the conductivity of the five-layer PANI thin film was 25.75 times higher than that of the monolayer film. This finding suggests that Ag doping alters the charge transport mechanisms in PANI thin films and warrants further investigation.

Keywords

• thin film
• polyaniline
• sol-gel
• Ag-doped
• multilayer

References

1. [1] Cherrington, R., & Liang, J., 2016, Materials and deposition processes for multifunctionality. Materials and Deposition Processes for Multifunctionality, 19-51.
2. [2] Bhadra, J., Alkareem, A., & Al-Thani, N., 2020, A review of advances in the preparation and application of polyaniline-based thermoset blends and composites. Journal of Polymer Research, 27, 102–122.
3. [3] Beygisangchin, M., Rashid, S., Shafie, S., Sadrolhosseini, A., & Lim, H., 2021, Preparations, properties, and applications of polyaniline and polyaniline thin films—a review. Polymers, 13(2), 46.
4. [4] Jaymand, M., 2013, Recent progress in chemical modification of polyaniline. Progress in Polymer Science, 138, 1287–1306.
5. [5] Rahayu, I., Eddy, D., Novianty, A., Anggreni, A., Bahti, H., & Hidayat, S., 2019, The effect of hydrochloric acid-doped polyaniline to enhance the conductivity. Materials Science and Engineering, 13th Joint Conference on Chemistry.
6. [6] Rajesh, A. J., 2016, Preparation and characterization of polyaniline thin films for sensor applications. Polymers, 4, 51–55.
7. [7] Beygisangchin, M., Arjmand, M., Sundararaj, U., & Park, C. B., 2021, Preparations, properties, and applications of polyaniline. Materials, 14(14), 4003.
8. [8] Kaushik, P., Singh, D., & Dutta, V., 2024, Progress in synthesis and applications of polyaniline: A review. Polymer, 298, 126987.

9. [9] Saini, P., Choudhary, V., Gupta, R., 2013, High permittivity polyaniline–barium titanate nanocomposites with excellent electromagnetic interference shielding response. Nanoscale, 5(10), 4330–4339
10. [10] Kakde, K., 2017, Synthesis and characterization of polyaniline doped with HCl, H2SO4, and PVA as secondary dopant for toxic gas (ammonia) sensor. Indian Journal of Science and Technology, 10, 1–4.
11. [11] Geethalakshmi, D., Muthukumarasamy, N., & Balasundaraprabhuc, R., 2014, Effect of dopant concentration on the properties of HCl-doped PANI thin films prepared at different temperatures. Optik, 125, 1307–131.
12. [12] Diliegros-Godines, C., Santos Cruz, J., Mathews, N. R., & Pal, M., 2018, Effect of Ag doping on structural, optical, and electrical properties of antimony sulfide thin films. Journal of Materials Science, 53, 11562–11573.
13. [13] Bahuguna, G., Mishra, N., Chaudhary, P., Kumar, A., & Singh, R., 2016, Thin film coating through sol-gel technique. Research Journal of Chemical Sciences, 6, 65–72.
14. [14] Diantoro, M., Purwaningtyas, D., Muthoharoh, N., Hidayat, A., Taufiq, A., & Fuad, A., 2012, The influence of iron- and copper-doped PANI thin film on their structure and dielectric properties. AIP Conference Proceedings, 1454, 268–271.
15. [15] Jarad, A., Ibrahim, K., & Nasser, A., 2016, Synthesis and characterization thin films of conductive polymer (PANI) for optoelectronic device application. International Conference on Nano-electronic Technology Devices and Materials.
16. [16] Chougale, U., Sadigale, S., Mulla, H., Patil, S., Kamble, B., & Fulari, V., 2020, Electropolymerised fibrous conducting polyaniline thin films for supercapacitor application. Bulletin of Laser and Spectroscopy Society of India, 26, 64.
17. [17] Jamil, N. Y., Burjus, A. Y., & Khalil, H. M. T., 2018, The effect of Ag doping on the structural, optical, and electrical properties of CdSe thin films. Rafidain Journal of Science, 27, 146–152.
18. [18] Kumar, H., Yadav, A., & Pandey, R. K., 2022, Ag₂O@PANI nanocomposites for advanced functional applications. Journal of Alloys and Compounds, 899, 163250.
19. [19] Badr, H., Mahallawi, I., Elrefaie, F., & Allam, N., 2019, Low temperature thermoelectric performance of novel polyaniline/iron oxide composites with superior Seebeck coefficient. Applied Physics A.,125,24.
20. [20] Butoi, B., Groza, A., Dinca, P., Balan, A., & Barna, V., 2017, Morphological and structural analysis of polyaniline and poly(o- anisidine) layers generated in a DC glow discharge plasma by using an oblique angle electrode deposition configuration. Polymers, 9, 732.
21. [21] Belgherbi, O., Seid, L., Lakhdari, D., Chouder, D., Akhtar, M., & Saeed, M., 2021, Optical and morphological properties of electropolymerized semiconductor polyaniline thin films: Effect of thickness. Journal of Electronic Materials, 50, 3876–3884.
22. [22] Nan, X., Zhou, J., Zhao, L., Wang, Y., Li, M., Xie, J., et al., 2024, A review of the establishment of effective conductive pathways of conductive polymer composites and advances in electromagnetic shielding. Polymers, 16(13), 2539.
23. [23] Naghdi, S., Rhee, K. Y., Hui, D., & Park, S., 2018, A review of conductive metal nanomaterials as conductive, transparent, and flexible coatings, thin films, and conductive fillers: different deposition methods and applications. Coatings, 8(8), 278.
24. [24] Al-Mur, B. A., Aljohani, H. A., Aldalbahi, A., Alqarni, M., Ali, S., Khan, S., et al., 2023, Silver anchored polyaniline@molybdenum disulfide nanocomposite (Ag/PANI@MoS₂) for highly efficient ammonia and methanol sensing under ambient conditions: a mechanistic approach. Nanomaterials, 13(4), 828.
25. [25] Kayishaer, A., Rehman, S., Kadir, A., Rahman, S., & Gul, H., 2024, Influence of surfactant on conductivity, capacitance and morphology of polyaniline films. Frontiers in Materials, 11, 1330790.
26. [26] Bednarczyk, K., Ciszewski, A., & Łapkowski, M., 2021, Effect of polyaniline content and protonating dopants on structural, conductive and morphological properties of polyaniline-based composites. Polymers, 13(7), 1095.
27. [27] Gawli, Y., Banerjee, A., Dhakras, D., Deo, M., Bulani, D., Wadgaonkar, P., Shelke, M., & Ogale, S., 2016, 3D polyaniline architecture by concurrent inorganic and organic acid doping for superior and robust high-rate supercapacitor performance. Scientific Reports, 6, 21002.
28. [28] Rani, G., Bhawna, & Ahlawat, R., 2024, A critical examination of polyaniline and its composite materials: Augmenting supercapacitor performance and diversifying application potential. Journal of Energy Storage, 97, 112690.
29. [29] Okafor, O. B., Popoola, A. P. I., Popoola, O. M., & Adeosun, S. O., 2025, Review on the recent development on polyaniline and transition metal oxides composite electrode for supercapacitor application. Results in Engineering, 22, 101926.
30. [30] Kim, Y.-G., Nguyen, H.-L., & Kinlen, P., 2021, Secondary dopants of electrically conducting polyanilines. Polymers, 13(17), 2904.
31. [31] Yadav, A. K., Mohammad, N., Chamanehpour, E., Mishra, Y. K., & Khanna, P. K., 2024, Polyaniline (PANI) nanocomposites with Se, Te and their metal chalcogenides: a review. RSC Applied Polymers, 2(5), 775–794.