Carbon Ash: From Waste Material to Flexible Paper-Based Pressure Sensor

Document Type : Original Article

Authors

1 College of Science, Al-Karkh University for Science, Baghdad, Iraq

2 College of Engineering, Al-Karkh University for Science, Baghdad, Iraq

10.22075/ppam.2026.40653.1209

Abstract

Carbon ash waste obtained from an Iraqi factory was converted into poly (vinyl alcohol) (PVA)-based composite materials intended for sensor applications. The carbon ash was ground, sieved through a 0.045 mm mesh, suspended in distilled water, and subsequently sonicated for 3 hours. The material was then dried at 100 °C for 15 min. Surface modification was carried out using acetic acid (S1), hydrochloric acid (S2), and sulfuric acid (S3) prior to embedding the modified carbon ash into the PVA matrix to form polymer composites. FTIR spectra showed absorption bands attributed to oxygen‑containing functional groups, which improved the interaction between the polymer and carbon ash, particularly in the S3 sample. Electrical conductivity increased to 15.1 S·cm⁻¹ for S3. Hall effect results indicated an increase in both carrier mobility and carrier concentration in the acid‑treated composites. Cyclic voltammetry showed that the S3 sample had the most pronounced electrochemical response, consistent with its enhanced chemical and electrical properties. Morphological analysis indicated improved filler dispersion in the acid‑treated composites, which exhibited a more uniform microstructure, particularly for S3. The pressure sensors fabricated from these materials demonstrated enhanced electromechanical performance, with S3 achieving the highest sensitivity and good structural stability.

Keywords

Main Subjects

© 2026 The Author(s). Progress in Physics of Applied Materials published by Semnan University Press. This is an open access article under the CC-BY 4.0 license. (https://creativecommons.org/licenses/by/4.0/)

References

[1] Sekertekin, Y., Bozyel, I. and Gokcen, D., 2020. A flexible and low-cost tactile sensor produced by screen printing of carbon black/PVA composite on cellulose paper. Sensors, 20(10), pp.2908.
[2] Cao, Y., Figueroa, J., Li, W., Chen, Z., Wang, Z.L. and Sepulveda, N., 2019. Understanding the dynamic response in ferroelectret nanogenerators to enable self-powered tactile systems and human-controlled micro-robots. Nano Energy, 63, pp.103852.
[3] Ahmad, J., Andersson, H. and Siden, J., 2019. Screen-Printed Piezoresistive Sensors for Monitoring Pressure Distribution in Wheelchair. IEEE Sensors Journal, 19, pp.2055-2063.
[4] Chi, C., Sun, X., Xue, N., Li, T. and Liu, C., 2018. Recent Progress in Technologies for Tactile Sensors. Sensors, 18, pp.948.
[5] Wan, Y., Wang, Y. and Guo, C.F., 2017. Recent progress on flexible tactile sensors. Materials Today Physics, 1, pp.61-73.
[6] Ajeev, A., Warfle, T., Maslaczynska-Salome, S., Alipoori, S., Duprey, C. and Wujcik, E.K., 2025. From the synthesis of wearable polymer sensors to their potential for reuse and ultimate fate. Chemical Science, 16(21), pp.9056-9075.
[7] Xu, Y., Fei, Q., Page, M., Zhao, G., Ling, Y., Stoll, S.B. and Yan, Z., 2021. Paper-based wearable electronics. iScience, 24, pp.102736.
[8] Su, Z., Yang, Y., Huang, Q., Chen, R., Ge, W., Fang, Z., Huang, F. and Wang, X., 2022. Designed biomass materials for “green” electronics: A review of materials, fabrications, devices, and perspectives. Progress in Materials Science, 125, pp.100917.
[9] Xu, Y., Zhao, G., Zhu, L., Fei, Q., Zhang, Z., Chen, Z., An, F., Chen, Y., Ling, Y., Guo, P., Ding, S., Huang, G., Chen, P., Cao, Q. and Yan, Z., 2022. Pencil-paper on-skin electronics. Proceedings of the National Academy of Sciences U. S. A., 117, pp.18292-18301.
[10] Sun, Q., Wang, L., Yue, X., Zhang, L., Ren, G., Li, D., Wang, H., Han, Y., Lulu, X., Lu, G., Yu, H.D. and Huang, W., 2021. Fully sustainable and high-performance fish gelatin-based triboelectric nanogenerator for wearable movement sensing and human-machine interaction. Nano Energy, 89, pp.106329.
[11] Li, S., Liu, G., Wen, H., Liu, G., Wang, H., Ye, M., Yang, Y., Guo, W. and Liu, Y., 2022. A skin‐like pressure‐and vibration‐sensitive tactile sensor based on polyacrylamide/silk fibroin elastomer. Advanced Functional Materials, 32(19), pp.2111747.
[12] Kadem, B.Y., 2025. AP0950 Structural, Morphological and Electrical Properties of SiC: PVA: PEDOT: PSS Paper-Based Materials for Flexible Strain Sensors. Iraqi Journal of Applied Physics, 21(4), pp.520-527.
[13] Hussain, F., M. Hojjati, M. Okamoto and Gorga, R.E., 2006. Review article: Polymer-matrix nanocomposites, processing, manufacturing, and application: An overview. Journal of Composite Materials, 40(17), pp.1511–1575.
[14] Dong, C., Campell, A.S., Eldawud, R., Perhinschi, G., Rojanasakul, Y. and Dinu, C.Z., 2013. Effects of acid treatment on structure, properties and biocompatibility of carbon nanotubes. Applied Surface Science, 264, pp.261-268.
[15] Goh, P.S., Wong, K.C., Yogarathinam, L.T., Ismail, A.F., Abdullah, M.S. and Ng, B.C., 2020. Surface modifications of nanofillers for carbon dioxide separation nanocomposite membrane. Symmetry, 12(7), pp.1102.
[16] Temuujin, J. and Van Riessen, A., 2009. Effect of fly ash preliminary calcination on the properties of geopolymer. Journal of Hazardous Materials, 164, pp.634–639.
[17] Liu, E., Cai, Z., Ye, Y., Zhou, M., Liao, H. and Yi, Y., 2023. An overview of flexible sensors: Development, application, and challenges. Sensors, 23(2), pp.817.
[18] Wei, Y., Shi, X., Yao, Z., Zhi, J., Hu, L., Yan, R. and Shi, C., 2023. Fully paper-integrated hydrophobic and air permeable piezoresistive sensors. npj Flexible Electronics, 7, pp.244.
[19] Han, J., Pan, J. and Cai, J., 2022. Self-sensing properties and piezoresistive effect of high ductility cementitious composite. Construction and Building Materials, 319, pp.126055.
[20] Bao, Y., Huang, X., Xu, J. and Cui, S., 2021. Effect of intramolecular hydrogen bonds on the single-chain elasticity of poly (vinyl alcohol): Evidencing the synergistic enhancement effect at the single-molecule level. Macromolecules, 54(15), pp.7314-7320.
[21] Sadiq, M., Khan, M.A., Hasan Raza, M.M., Aalam, S.M., Zulfequar, M. and Ali, J., 2022. Enhancement of electrochemical stability window and electrical properties of CNT-Based PVA–PEG polymer blend composites. ACS Omega, 7(44), pp.40116-40131.
[22] Pranav, C.M., Madhu, G.M., Koteswararao, J. and Kottam, N., 2020. Mechanical and electrical properties evaluation of PVA-carbon dot polymer nanocomposites. Indian Journal of Chemical Technology, 27(6), pp.492-498.
[23] Allayarov, S.R., Confer, M.P., Dixon, D.A., Rudneva, T.N., Kalinin, L.A., Tolstopyatov, E.M., Frolov, I.A., Ivanov, L.F., Grakovich, P.N. and Golodkov, O.N., 2020. Effect of initial γ-irradiation on infrared laser ablation of poly (vinyl alcohol) studied by infrared spectroscopy. Polymer Degradation and Stability, 181, pp.109331.
[24] Hakuto, N., Saito, K., Kirihara, M. and Kotsuchibashi, Y., 2020. Preparation of cross-linked poly(vinyl alcohol) films from copolymers with benzoxaborole and carboxylic acid groups, and their degradability in an oxidizing environment. Polymer Chemistry, 11 (14), pp.2469–2474.
[25] Azhagapillai, P., Al Shoaibi, A. and Chandrasekar, S., 2021. Surface functionalization methodologies on activated carbons and their benzene adsorption. Carbon Letters, 31(3), pp.419-426.
[26] Putro, P.A., Yudasari, N., Isnaeni, I. and Maddu, A., 2021. Spectroscopy study of polyvinyl alcohol/carbon dots composite films. Walailak Journal of Science and Technology, 18(7), pp.9184.
[27] Kadem, B., Cranton, W. and Hassan, A., 2015. Metal salt modified PEDOT: PSS as anode buffer layer and its effect on power conversion efficiency of organic solar cells. Organic Electronics, 24, pp.73–79.
[28] Al-Khafaji, R.S.A., 2021. Synthesis of blend polymer (PVA/PANI)/Copper (1) oxide nanocomposite: thermal analysis and UV-Vis spectra specifications. Iraqi Journal of Science, 62(11), pp.3888-3900.
[29] Alghunaim, N.S., 2016. Optimization and spectroscopic studies on carbon nanotubes/PVA nanocomposites. Results in Physics, 6, pp.456-460.
[30] Ahmad, J., Deshmukh, K. and Hägg, M.B., 2013. Influence of TiO2 on the chemical, mechanical, and gas separation properties of polyvinyl alcohol-titanium dioxide (PVA-TiO2) nanocomposite membranes. International Journal of Polymer Analysis and Characterization, 18(4), pp.287-296.
[31] Ahmad, J., Deshmukh, K., Habib, M. and Hägg, M.B., 2014. Influence of TiO2 nanoparticles on the morphological, thermal and solution properties of PVA/TiO2 nanocomposite membranes. Arabian Journal for Science and Engineering, 39(10), pp.6805-6814.
[32] Mohanapriya, M.K., Deshmukh, K., Chidambaram, K., Ahamed, M.B., Sadasivuni, K.K., Ponnamma, D., AlMaadeed, M.A.A., Deshmukh, R.R. and Pasha, S.K., 2017. Polyvinyl alcohol (PVA)/polystyrene sulfonic acid (PSSA)/carbon black nanocomposite for flexible energy storage device applications. Journal of Materials Science: Materials in Electronics, 28(8), pp.6099-6111.
[33] Pawde, S.M., Deshmukh, K. and Parab, S., 2008. Preparation and characterization of poly (vinyl alcohol) and gelatin blend films. Journal of Applied Polymer Science, 109(2), pp.1328-1337.
[34] Cheong, J.Y., Koay, J.S.C., Gopal, S.R., Velayutham, T.S. and Gan, W.C., 2025. Enhancing the tribopositive characteristics of polyvinyl alcohol (PVA)-carbon composites by optimizing the PVA-carbon interaction with various carbon fillers. Nanoscale Advances, 7(3), pp.819-829.
[35] Hu, M., Gu, X., Hu, Y., Deng, Y. and Wang, C., 2016. PVA/carbon dot nanocomposite hydrogels for simple introduction of Ag nanoparticles with enhanced antibacterial activity. Macromolecular Materials and Engineering, 301(11), pp.1352-1362.
[36] Lee, M. and Park, J.S., 2024. Enhanced performance and durability of pore-filling membranes for anion exchange membrane water electrolysis. Membranes, 14(12), pp.269.
[37] Bantu, T.R., Tom, R.T., Sebasian, D.P. and Kumar, A.C., 2025. Mechanical and Morphological Enhancement of PVA Composites using Crotalaria pallida Fibers. Malaysian Journal of Chemistry, 27(4), pp.207-217.
[38] Suganthi, S., Vignesh, S., Kalyana Sundar, J. and Raj, V., 2020. Fabrication of PVA polymer films with improved antibacterial activity by fine-tuning via organic acids for food packaging applications. Applied Water Science, 10 (4), pp.1-11.
[39] Rahman, M.M., Khan, K.H., Parvez, M.M.H., Irizarry, N. and Uddin, M.N., 2025. Polymer nanocomposites with optimized nanoparticle dispersion and enhanced functionalities for industrial applications. Processes, 13(4), pp.994.
[40] Hadhy, R.A. and Kadem, B.Y., 2019. Gel Polymer Electrolyte Based on SiC: PVA Composites for Body motion Sensor and Paper Based Application. In 2019 12th International Conference on Developments in eSystems Engineering (DeSE), pp.730-735.
[41] Al-Bermany, E., Qais, D. and Al-Rubaye, S., 2019. Graphene effect on the mechanical properties of poly (ethylene oxide)/graphene oxide nanocomposites using ultrasound technique. Journal of Physics: Conference Series, 1234(1), pp.012011.
[42] Abed, T.H., Abed, M.M., Kadem, B.Y. and Jaiad, A.T., 2021. Rechargeable flexible paper battery using PAV, PSSPEDOT polymer. IOP Conference Series: Earth and Environmental Science, 877(1), pp.012037.
[43] Katagiri, T., Kodama, S., Kawahara, K., Umemoto, K., Miyoshi, T. and Nakayama, T., 2024. Response Characteristics of Pressure-Sensitive Conductive Elastomer Sensors Using OFC Electrode with Triangular Wave Concavo-Convex Surfaces. Sensors, 24(7), pp.2349.
Progress in Physics of Applied Materials
Volume 6, Issue 4 - Serial Number 13
In Progress
December 2026
Pages 331-341

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History

  • Receive Date: 20 February 2026
  • Revise Date: 08 May 2026
  • Accept Date: 11 May 2026

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