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Proceeding Paper

Investigation of the Electrical Properties of Graphene-Reinforced Geopolymer Composites †

Department of Mechanical Engineering, Birla Institute of Technology and Science Pilani Hyderabad Campus, Secunderabad 500078, Telangana, India
Department of Mechanical Engineering, Veer Surendra Sai University of Technology, Burla 768018, Odisha, India
Department of Civil Engineering, National Institute of Technology Durgapur, Durgapur 713209, West Bengal, India
Faculty of Materials Engineering and Physics, Cracow University of Technology, Jana Pawła II 37, 31-864 Cracow, Poland
Department of Engineering Design and Mathematics, The University of the West of England, Bristol BS16 1QY, UK
Department of Environment & Sustainability, CSIR—Institute of Minerals and Materials Technology, Bhubaneswar 751013, Odisha, India
Author to whom correspondence should be addressed.
Presented at the 10th MATBUD’2023 Scientific-Technical Conference “Building Materials Engineering and Innovative Sustainable Materials”, Cracow, Poland, 19–21 April 2023.
Mater. Proc. 2023, 13(1), 34;
Published: 15 February 2023
(This article belongs to the Proceedings of 10th MATBUD’2023 Scientific-Technical Conference)


Geopolymer composites provide an environmentally friendly alternative to cement-based composites in the construction industry. Due to their distinctive material composition, geopolymers also exhibit electrically conductive properties, which permit their application as a functional material. The current work aims to study the distinctive electrical properties of fly-ash-based geopolymer composites. Varying dosages of graphene oxide (i.e., 0, 0.1, 0.2, 0.3, 0.4% (by wt. of binder)) were introduced into the geopolymer matrix to enhance electrical conductivity. While GO (graphene oxide) is typically less conductive, the interaction of GO sheets with the alkaline solution during geopolymerisation reduced the functional groups and produced cross-linked rGO (reduced graphene oxide) sheets with increased mechanical and electrical conductivity properties. Solid-state impedance spectroscopy was used to characterize the electrical properties of geopolymer composites in terms of several parameters, such as impedance, electrical conductivity and dielectric properties, within the frequency ranging from 101 to 105 Hz. The relationship between the electrical properties and graphene oxide reinforcement can effectively establish geopolymer composite development as smart materials with desirable functionality. The results suggest an effective enhancement in electrical conductivity of up to 7.72 × 10−13 Ω⋅mm−1 and the dielectric response performance of graphene-reinforced fly-ash-based geopolymer composites.

1. Introduction

Geopolymers—at the micro-level—are primarily composed of amorphous materials of the long matrix, cross-linked polymer chains of tetrahedral AlO4 and SiO4 units [1,2]. Geopolymers are usually dielectric materials due to the silica content and alkali metal ions, which could work as ionic conductors via an applied electric field [3,4]. Although pure geopolymers are electrically conductive due to the availability of water molecules and hydroxide in their composition, the open pore networks in the matrix produce conductivity [5,6]. Therefore, the introduction of filler materials becomes predominately necessary to improve electrical conductivity [7,8]. The most common additives preferred for the fabrication of conductive geopolymer composites include carbon and metallic fillers, such as carbon fibres [5,9], nanotubes [10,11], graphite [8], graphene derivatives [7,8], steel fibres, etc.
Several research projects have been carried out to study and comprehend the influence of conductive fillers in the geopolymer matrix system. In one such examination, Payakaniti et al. optimized the inclusion of carbon fibre and stated that 0.5 wt.% provided superior electrical conductivity as well as mechanical properties [12,13]. Similar examinations were also carried out with carbon nanotubes [11,14]. The incorporation of 1 wt.% carbon nanotube in the geopolymer matrix enhanced the electrical conductivity performance by almost three times. Carbon nanotubes also reduce the electric resistance and impedance of associated composites [11,15]. Thus, it can be argued that the physical characteristics and the synthesis mechanisms of the conductive fillers play a vital role in the enhancement of geopolymer properties.
Research on the electrical properties of geopolymer composites is still a novel, diverse and challenging area, resulting in a lack of a universal approach and indicating the high complexity of the underlying problem [16]. Presently, one of the most promising multifunctional composites seems to be geopolymers incorporating graphene derivatives. The current study is therefore focused on the investigation of different effects of GO dosages (0, 0.1, 0.2, 0.3 and 0.4 wt.%) on the electrical properties and the dielectric response of fly-ash-based GRGC (graphene-reinforced geopolymer composite) specimens.

2. Experimental Procedure

2.1. Materials

Fly ash was procured from NTPC, Kaniha, in Odisha. The chemical composition of the FA (fly ash) mostly contained SiO2 and Al2O3 with 60.34 and 30.83 wt.%, respectively. The particle size of FA was 19.18804 μm (median) and 36.73520 μm (mean). Low-cost GO synthesized via mechanical exfoliation with a layer thickness (>10 stacking layers) was given by CSIR-IMMT, Odisha. The particle size of the GO varied from 3 to 200 nm. NaOH flakes were of 99.6% purity, and the Na2SiO3 solution consisted of Na2O (15.85 wt.%), SiO2 (32.15 wt.%), and H2O (52 wt.%).

2.2. GRGC Fabrication

A NaOH solution of 12M was prepared by mixing 480 g of NaOH flakes and 1000 mL of tap water, resulting in an exothermic reaction. GRGC specimens were prepared in 5 different batches with varying GO additions (0, 0.1, 0.2, 0.3 and 0.4) wt.% of FA, as shown in Table 1. The alkali activator solution was mixed via a magnetic stirrer at low rpm. GO was consequently introduced to the solution carefully to achieve maximum dispersion and to avoid the agglomeration phenomenon. Later, the solution was ultrasonicated for 30 min and mixed with FA for 10-15 min. The geopolymer slurry was poured into custom molds (10 × 3) mm3 and cured at 25 °C (±3 °C) for 24 hr. The GRGC specimens were demolded and cured in ambient conditions for 28 days. Figure 1a illustrates the cured GRGC specimens prior to SSIS (solid state impedance spectroscopy) characterization studies. The specimens were polished with emery paper at different grift sizes to obtain the necessary dimensions for the experimental setup, as shown in Figure 1a,b, for precise results.

2.3. Testing Methods

Solid State Impedance Spectroscopy

The SSIS results were obtained from HIOKI IMPEDANCE ANALYZER IM3570 (AC) using LCR sample application software. The GRGC specimens were investigated using the two-probe method with electrodes, as depicted in Figure 1b, in a dry state under ambient laboratory conditions. The values for different parameters, such as impedance, capacitance and tan delta over a frequency range of 101 to 105 Hz, were obtained from the instrument. The values of the dielectric constant, dielectric loss and conductivity were calculated from Equations (1) to (4) [17,18,19]:
ε r = C P t ε 0 A
D = ε r ε r
ω = 2 π f
σ = ε 0 ε r ω
  • Cp = capacitance of the specimen;
  • t = thickness of the specimen;
  • ε0 = permittivity of free space constant (8.854 × 10−12 F/m);
  • εr = dielectric constant
  • εr″ = dielectric loss
  • A = area of the electrode (113.09 mm2);
  • f = frequency;
  • ω = angular frequency;
  • σ = conductivity.

3. Results and Discussion

3.1. Solid-State Impedance Spectroscopy

3.1.1. Capacitance and Impedance/Resistance

The degree of (Cp) and (Z) of the GRGC specimens can be perceived in Figure 2a,b. At a lower frequency (101 Hz), higher capacitance values ranging from 9.26 × 10−10 to 4.5 × 10−9 were obtained, but the (Cp) values tend to drop and become constant (almost zero) at higher frequencies (i.e., specifically after 103 Hz). The incorporation of GO in the geopolymer composites results in higher (Cp) values, whereas in an opposite trend, lower (Z) was observed with a higher dosage of GO (4.36 × 105 Ω). The impedance of all geopolymer composites became almost constant at higher frequencies, but higher impedance values were observed at lower frequencies for GRGC0 specimens with no addition of GO (5.32 × 106 Ω). This could suggest that GRGC4 specimens offer minimal resistance and accelerate the movement of ions in the GRGC matrix in contrast with the GRGC0 specimen. This could also be signified by the acceleration effect of GO on the polycondensation reaction of the geopolymer composites [7]. The reduction in functional groups from GO may have enhanced the electrical conductivity properties of reduced GO (i.e., rGO), as similarly noted in the study by Saffi et al. [20].

3.1.2. Dielectric Constant, Dielectric Loss and Tangent Loss/Tan Delta

Figure 2c,d show the resulting values of dielectric constant (εr) and dielectric loss (εr″) for different GRGC specimens when measured at different frequencies. The incorporation of GO in the geopolymer mix leads to higher (εr) and (εr″) values of (10−5–10−4) and (10−4–10−3) at low frequencies, respectively. Both (εr) and (εr″) show a significant decrease with the increase in frequency initially. However, the decrease rate of (εr) and (εr″) was reduced at a higher frequency range and reached an approximately constant value. This phenomenon of the dielectric properties of GRGC specimens can be attributed to the polarization relaxation of molecules in the GRGC matrix. Initially, at lower frequencies, the molecules in the matrix have sufficient time and start orienting in the direction of the applied current. Consequently, at higher frequencies, the re-orientation is limited due to which the values of both (εr) and (εr″) are reduced drastically [21]. The polarization of the molecules can be firmly influenced by different aspects of the geopolymer mix, i.e., alumino-silicate gel, unreacted particles, impurities available in the composite mix, etc. A study by Hanjitsuwan et al. observed a similar phenomenon and described the rationale as electrode/specimen interfacial polarization and double-layer polarization [17,18]. Alternative polarization mechanisms include ionic, dipolar or molecular, electronic and atomic mechanisms [22].
The (D) curves for the GRGC specimens are exhibited in Figure 2e. The (D) curve peaks ranged between 3.06 and 12.7 and ought to be related to the trend of the dielectric properties. However, GRGC3 obtained the highest (D) value: 101 Hz. The (D) values decreased with an increase in frequency, and the curves became almost constant at higher frequencies for all GRGC specimens. This exception can be closely related to the compactness of the specimens and the function of GO in enhancing the strength of the composites primarily via their pore-filling characteristics. Earlier investigations also indicated the limit of GO (0.1–0.3 wt.%) in improving the strength of geopolymer composites, as higher dosages tend to decrease the compactness due to the consequence of agglomeration [16,23,24,25,26].

3.1.3. Conductivity

Figure 2f illustrates the conductivity (σ) results of the GRGC specimens. The conductivity values increase with the increase in GO dosage and range between 6.05 × 10−14 and 7.72 × 10−13 Ω⋅mm−1 for GRGC0 and GRGC4 at low frequencies of (101) Hz, respectively. The in situ reduction of GO improved electrical conductivity properties and contributed to enhancing GRGC conductive properties. At higher frequencies (i.e., 105 Hz), (σ) increased for all GRGC specimens, and the corresponding values include 1.18 × 10−12–2.27 × 10−12 Ω⋅mm−1. At lower frequencies, the (σ) of the GRGC specimens remained approximately constant. However, the increment in conductivity is significantly higher when the frequency is more than 104 Hz. This occurrence could be associated with the geopolymerisation reaction. The study by Hanjitsuwan et al. detected the same trend of increased conductivity for the geopolymer pastes with increased frequencies [17,18]. The molecular structure of geopolymeric gel is attributed to the increment of electrical conductivity at higher frequencies, mostly via the Na+ ion hopping mechanism between the cation sites. A higher dosage of graphene in geopolymer composites leads to higher conductivity. Still, a significant increase in conductivity was observed at higher frequencies, which could be explained via the combination of Na+ ion hopping and the electronic conductivity of in situ reduced GO, leading to the shortening of conduction distance. Thus, GO could be considered an effective agent for improving the (σ) of geopolymer composites for different applications [12]. The relationship between the (Z) and (σ) curves demonstrates the homogenous dispersion of GO in the geopolymer matrix since the agglomeration of GO could lead to improper conductivity in the GRGC specimens. The results also suggest that there might be a percolation threshold between 0.1 and 0.2 wt.% GO addition in the GRGC matrix. The manifestation is evident via the slight difference in the behaviour of curves in Figure 2b,f. Therefore, it can be considered that conductive fillers such as GO largely facilitate conductivity in geopolymer composites and can be tailored for appropriate piezoresistive responses according to the required applications.
Figure 2. Influence of GO on different electrical parameters of geopolymer composites: (a) capacitance, (b) impedance, (c) dielectric constant, (d) dielectric loss, (e) tan delta and (f) conductivity.
Figure 2. Influence of GO on different electrical parameters of geopolymer composites: (a) capacitance, (b) impedance, (c) dielectric constant, (d) dielectric loss, (e) tan delta and (f) conductivity.
Materproc 13 00034 g002

4. Conclusions

In this study, different dosages of low-cost GO were incorporated in geopolymer composites to fabricate sustainable GRGC specimens for various smart applications. SSIS investigations were conducted at room temperature to characterize and assess the significant dielectric properties of GRGC specimens, which are concluded as follows.
The interaction of the GO sheets with the alkaline activator in geopolymeric reactions produced highly reduced and cross-linked GO sheets, enhancing the electrical conductivity properties of the composites.
At 101 Hz, GRGC specimens with 0.4 wt.% GO obtained a maximum ionic/electrical conductivity of 7.72 × 10−13 Ω⋅mm−1 and a minimum impedance of 4.36 × 105 Ω, suggesting desirable low-frequency-based applications.
A percolation threshold was observed between 0.1 and 0.2 wt.% of GO introduction in the geopolymer matrix.
Increasing the GO dosage up to 0.4 wt.% aided in reducing the electrical impedance of GRGC specimens up to 91.81%.

Author Contributions

Conceptualization: R.S.K.; methodology: R.S.K.; formal analysis: R.S.K.; investigation: R.S.K.; resources: S.M.M.; writing—original draft preparation: R.S.K., S.S. and K.K.; writing—review and editing: T.S.Q. All authors have read and agreed to the published version of the manuscript.


The first author would like to acknowledge the funding of 500$ received through the ASTM International Student Project Grant Award 2021, USA.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Not applicable.


The authors would like to thank Ashok Kumar Sahu and Muhammad Shahid Anwar of CSIR—Institute of Minerals and Materials Technology (CSIR-IMMT)—India, for the materials, facility and support necessary for the experimental work, along with the proofreading of the article. The authors are also grateful for Tanvir Qureshi’s IFA New Starters Award at UWE Bristol, UK. The publication cost of this paper was covered with funds from the Polish National Agency for Academic Exchange (NAWA): “MATBUD’2023—Developing international scientific cooperation in the field of building materials engineering” BPI/WTP/2021/1/00002, MATBUD’2023.

Conflicts of Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.


  1. Krishna, R.S.; Mishra, J.; Meher, S.; Das, S.K.; Mustakim, S.M.; Singh, S.K. Industrial Solid Waste Management through Sustainable Green Technology: Case Study Insights from Steel and Mining Industry in Keonjhar, India. In Proceedings of the 2nd International Conference on Processing and Characterization of Materials, Rourkela, India, 12–14 December 2019; Volume 33, pp. 5243–5249. [Google Scholar]
  2. Mishra, J.; Kumar Das, S.; Krishna, R.S.; Nanda, B.; Kumar Patro, S.; Mohammed Mustakim, S. Synthesis and Characterization of a New Class of Geopolymer Binder Utilizing Ferrochrome Ash (FCA) for Sustainable Industrial Waste Management. Mater Today Proc. 2020, 33, 5001–5006. [Google Scholar] [CrossRef]
  3. Cai, J.; Pan, J.; Li, X.; Tan, J.; Li, J. Electrical Resistivity of Fly Ash and Metakaolin Based Geopolymers. Constr. Build. Mater. 2020, 234, 117868. [Google Scholar] [CrossRef]
  4. Essaidi, N.; Nadir, H.; Martinod, E.; Feix, N.; Bertrand, V.; Tantot, O.; Lalande, M.; Rossignol, S. Comparative Study of Dielectric Properties of Geopolymer Matrices Using Different Dielectric Powders. J. Eur. Ceram Soc. 2017, 37, 3551–3557. [Google Scholar] [CrossRef]
  5. Wanasinghe, D.; Aslani, F.; Ma, G. Effect of Carbon Fibres on Electromagnetic-Interference-Shielding Properties of Geopolymer Composites. Polymers 2022, 14, 3750. [Google Scholar] [CrossRef] [PubMed]
  6. Nguyen, V.V.; Le, V.S.; Louda, P.; Szczypiński, M.M.; Ercoli, R.; Růžek, V.; Łoś, P.; Prałat, K.; Plaskota, P.; Pacyniak, T.; et al. Low-Density Geopolymer Composites for the Construction Industry. Polymers 2022, 14, 304. [Google Scholar] [CrossRef]
  7. Long, W.-J.; Zhang, X.-H.; Dong, B.-Q.; Fang, Y.; Ye, T.-H.; Xie, J. Investigation of Graphene Derivatives on Electrical Properties of Alkali Activated Slag Composites. Materials 2021, 14, 4374. [Google Scholar] [CrossRef] [PubMed]
  8. Mizerová, C.; Kusák, I.; Rovnaník, P. Electrical properties of fly ash geopolymer composites with graphite conductive admixtures. Acta Polytech CTU Proc. 2019, 22, 72–76. [Google Scholar] [CrossRef]
  9. Farhan, K.Z.; Johari, M.A.M.; Demirboğa, R. Impact of Fiber Reinforcements on Properties of Geopolymer Composites: A Review. J. Build. Eng. 2021, 44, 102628. [Google Scholar] [CrossRef]
  10. Ranjbar, N.; Zhang, M. Fiber-Reinforced Geopolymer Composites: A Review. Cem. Concr. Compos. 2020, 107, 103498. [Google Scholar] [CrossRef]
  11. Su, Z.; Hou, W.; Sun, Z. Recent Advances in Carbon Nanotube-Geopolymer Composite. Constr. Build. Mater. 2020, 252, 118940. [Google Scholar] [CrossRef]
  12. Payakaniti, P.; Pinitsoontorn, S.; Thongbai, P.; Amornkitbamrung, V.; Chindaprasirt, P. Electrical Conductivity and Compressive Strength of Carbon Fiber Reinforced Fly Ash Geopolymeric Composites. Constr. Build. Mater. 2017, 135, 164–176. [Google Scholar] [CrossRef]
  13. Payakaniti, P.; Pinitsoonthorn, S.; Thongbai, P.; Amornkitbamrung, V.; Chindaprasirt, P. Effects of Carbon Fiber on Mechanical and Electrical Properties of Fly Ash Geopolymer Composite. Mater. Today Proc. 2018, 5, 14017–14025. [Google Scholar] [CrossRef]
  14. Górski, M.; Czulkin, P.; Wielgus, N.; Boncel, S.; Kuziel, A.W.; Kolanowska, A.; Jędrysiak, R.G. Electrical Properties of the Carbon Nanotube-Reinforced Geopolymer Studied by Impedance Spectroscopy. Materials 2022, 15, 3543. [Google Scholar] [CrossRef]
  15. Kusak, I.; Lunak, M.; Rovnanik, P. Electric Conductivity Changes in Geopolymer Samples with Added Carbon Nanotubes. Procedia Eng. 2016, 151, 157–161. [Google Scholar] [CrossRef][Green Version]
  16. Krishna, R.S.; Mishra, J.; Nanda, B.; Patro, S.K.; Adetayo, A.; Qureshi, T.S. The Role of Graphene and Its Derivatives in Modifying Different Phases of Geopolymer Composites: A Review. Constr. Build. Mater. 2021, 306, 124774. [Google Scholar] [CrossRef]
  17. Hanjitsuwan, S.; Chindaprasirt, P.; Pimraksa, K. Electrical Conductivity and Dielectric Property of Fly Ash Geopolymer Pastes. Int. J. Miner. Metall. Mater. 2011, 18, 94–99. [Google Scholar] [CrossRef]
  18. Hanjitsuwan, S.; Hunpratub, S.; Thongbai, P.; Maensiri, S.; Sata, V.; Chindaprasirt, P. Effects of NaOH Concentrations on Physical and Electrical Properties of High Calcium Fly Ash Geopolymer Paste. Cem. Concr. Compos. 2014, 45, 9–14. [Google Scholar] [CrossRef]
  19. Sellami, M.; Barre, M.; Toumi, M. Synthesis, Thermal Properties and Electrical Conductivity of Phosphoric Acid-Based Geopolymer with Metakaolin. Appl. Clay Sci. 2019, 180, 105192. [Google Scholar] [CrossRef]
  20. Saafi, M.; Tang, L.; Fung, J.; Rahman, M.; Liggat, J. Enhanced Properties of Graphene/Fly Ash Geopolymeric Composite Cement. Cem. Concr. Res. 2015, 67, 292–299. [Google Scholar] [CrossRef][Green Version]
  21. Chuewangkam, N.; Nachaithong, T.; Chanlek, N.; Thongbai, P.; Pinitsoontorn, S. Mechanical and Dielectric Properties of Fly Ash Geopolymer/Sugarcane Bagasse Ash Composites. Polymers 2022, 14, 1140. [Google Scholar] [CrossRef]
  22. Malkawi, A.B.; Al-Mattarneh, H.; Achara, B.E.; Mohammed, B.S.; Nuruddin, M.F. Dielectric Properties for Characterization of Fly Ash-Based Geopolymer Binders. Constr. Build. Mater 2018, 189, 19–32. [Google Scholar] [CrossRef]
  23. Krishna, R.S.; Mishra, J.; Das, S.K.; Mustakim, S.M. An Overview of Current Research Trends on Graphene and It’s Applications. Worls Sci. News 2019, 132, 206–219. [Google Scholar]
  24. Krishna, R.S.; Mishra, J.; Adetayo, A.; Das, S.K.; Mustakim, S.M. Green Synthesis of High-Performance Graphene Reinforced Geopolymer Composites: A Review on Environment-Friendly Extraction of Nanomaterials. Iranian J. Mater. Sci. Eng. 2020, 17, 10–24. [Google Scholar]
  25. Krishna, R.S.; Mishra, J.; Das, S.K.; Nanda, B.; Patro, S.K.; Mustakim, S.M. A Review on Potential of Graphene Reinforced Geopolymer Composites. In Tailored Functional Materials; Mukherjee, K., Layek, R.K., De, D., Eds.; Springer: Singapore, 2022; Volume 15, pp. 43–60. [Google Scholar]
  26. Das, S.K.; Krishna, R.S.; Mishra, S.; Mustakim, S.M.; Jena, M.K.; Tripathy, A.K.; Sahu, T. Future Trends Nanomaterials in Alkali-Activated Composites. In Handbook of Sustainable Concrete and Industrial Waste Management; Colangelo, F., Cioffi, R., Farina, I., Eds.; Woodhead Publishing: Cambridge, UK, 2021. [Google Scholar]
Figure 1. GRGC characterization process: (a) specimen specifications and (b) SSIS measurement methodology.
Figure 1. GRGC characterization process: (a) specimen specifications and (b) SSIS measurement methodology.
Materproc 13 00034 g001
Table 1. GRGC mixture composition.
Table 1. GRGC mixture composition.
MixtureFA (g)NaOH Soln. (g)Na2SiO3 Soln. (g)NaOH/Na2SiO3Liquid/BinderGO (wt.%)
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Krishna, R.S.; Saha, S.; Korniejenko, K.; Qureshi, T.S.; Mustakim, S.M. Investigation of the Electrical Properties of Graphene-Reinforced Geopolymer Composites. Mater. Proc. 2023, 13, 34.

AMA Style

Krishna RS, Saha S, Korniejenko K, Qureshi TS, Mustakim SM. Investigation of the Electrical Properties of Graphene-Reinforced Geopolymer Composites. Materials Proceedings. 2023; 13(1):34.

Chicago/Turabian Style

Krishna, R. S., Suman Saha, Kinga Korniejenko, Tanvir S. Qureshi, and Syed Mohammed Mustakim. 2023. "Investigation of the Electrical Properties of Graphene-Reinforced Geopolymer Composites" Materials Proceedings 13, no. 1: 34.

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