Electrical conductivity and dielectric property of fly ash geopolymer pastes

Abstract

The electrical conductivity and dielectric property of fly ash geopolymer pastes in a frequency range of 100 Hz-10 MHz were studied. The effects of the liquid alkali solution to ash ratios (L/A) were analyzed. The mineralogical compositions and microstructures of fly ash geopolymer materials were also investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The 10 mol sodium hydroxide solution and sodium silicate solution at a sodium silicate-to-sodium hydroxide ratio of 1.0 were used in making geopolymer pastes. The pastes were cured at 40°C. It is found that the electrical conductivity and dielectric constant are dependent on the frequency range and L/A ratios. The conductivity increases but the dielectric constant decreases with increasing frequency.

Keywords

fly ash / inorganic polymers / dielectric properties / electrical conductivity

References

[1] Jo B.W., Park S.K., Park J.B. Properties of concrete made with alkali-activated fly ash lightweight aggregate (AFLA). Cem. Concr. Compos., 2007, 29(2): 128.

[2] Chindaprasirt P., Jaturapitakkul C., Chalee W., Rattanasak U. Comparative study on the characteristics of fly ash and bottom ash geopolymers. Waste Manage., 2007, 29(2): 539.

[3] Chindaprasirt P., Chareerat T., Sirivivatnanon V. Workability and strength of coarse high calcium fly ash geopolymer. Cem. Concr. Compos., 2007, 29(3): 224.

[4] Rattanasak U., Chindaprasirt P. Influence of NaOH solution on the synthesis of fly ash geopolymer. Miner. Eng., 2009, 22(12): 1073.

[5] De Silva P., Sagoe-Crenstil K., Sirivivatnanon V. Kinetics of geopolymerization: Role of Al₂O₃ and SiO₂. Cem. Concr. Res., 2007, 37(4): 512.

[6] Sathonsaowaphak A., Chindaprasirt P., Pimraksa K. Workability and strength of lignite high bottom ash geopolymer mortar. J. Hazard. Mater., 2009, 168(1): 44.

[7] Detphan S., Chindaprasirt P. Preparation of fly ash and rice husk ash geopolymer. Int. J. Miner. Metall. Mater., 2009, 16(6): 720.

[8] Mackenzie K.J.D., Bolton M.J. Electrical and mechanical properties of aluminosilicate inorganic polymer composites with carbon nanotubes. J. Mater. Sci., 2009, 44(11): 2851.

[9] Cui X.M., Zheng G.J., Han Y.C., Su F., Zhou J. A study on electrical conductivity of chemosynthetic Al₂O₃-2SiO₂ geopolymer materials. J. Power Sources, 2008, 184(2): 652.

[10] Swain D., Guru Row T.N. Structure, ionic conduction and dielectric relaxation in a novel fast ion conductor, Na₂Cd(SO₄)₂. Chem. Mater., 2007, 19(3): 347.

[11] Kasap S.O. Principle of Electronic Materials and Devices, 2002 Boston, McGraw Hill, 507.

[12] Van Beek A., Hilhorst M.A. Dielectric measurements to characterize the microstructural changes of young concrete. Heron, 1999, 44(1): 3.

[13] Li J., Zhang Y., Cui X. The influence of free water content on dielectric properties of alkali active slag cement paste. J. Wuhan Univ. Technol. Mater. Sci. Ed., 2007, 22(4): 774.

[14] Zhang X., Dink X.Z., Ong C.K., Tan B.T.G., Yang J. Dielectric and electrical properties of ordinary Portland cement and slag cement in the early hydration period. J. Mater. Sci., 1996, 31(5): 1345.

[15] Criado M., Fernández-Jiménez A., Torre A.G. d. l., Aranda M.A.G., Palomo A. An XRD study of the effect of the SiO₂/Na₂O ratio on the alkali activation of fly ash. Cem. Concr. Res., 2007, 37(5): 671.

[16] Duxson P., Fernandez-Jimenez A., Provis J.L., Lukey G.C., Palomo A., Van Deventer J.S.J. Geopolymer technology: the current state of art. J. Mater. Sci., 2007, 42(9): 2917.

[17] Alvarex-Ayuso E., Queraol X., Plana F., Alastuey A., Moreno N., Izquierdo M., Font O., Moreno T., Diex S., Vazquez E., Barra M. Environmental, physical and structural characterisation of geopolymer matrixes synthesised from coal (co-) combustion fly ashes. J. Hazard. Mater., 2008, 154(1–3): 175.

[18] Huang S., Ye Z., Hu Y., Chang J., Lu L., Cheng X. Effect of forming pressures on electric properties of piezoelectric ceramic/sulphoaluminate cement composites. Compos. Sci. Technol., 2007, 67(1): 135.

[19] Wang L.L., Sui W.M., Mu K.C., Luan S.J. Effect of silica sintering additive on the sintering behavior and dielectric properties of strontium barium niobate ceramics. J. Eur. Ceram. Soc., 2009, 29(8): 1427.

[20] Damson B., Würschum R. Correlation between the kinetics of the amorphous-to-nanocrystalline transformation and the diffusion in alloys. J. Appl. Phys., 1996, 80(2): 747.

[21] Sun M., Li Z., Mao Q., Shen D. Study on the hole conduction phenomenon in carbon fiber-reinforced concrete. Cem. Concr. Res., 1998, 28(4): 549.

[22] McCarter W.J., Chrisp T.M., Starrs G., Blewett J. Characterization and monitoring of cement-based systems using intrinsic electrical property measurements. Cem. Concr. Res., 2003, 33(2): 197.

[23] Chaipanich A. Dielectric and piezoelectric of PZT-cement composites. Curr. Appl. Phys., 2007, 7(5): 537.

[24] Li Z., Zhang D., Wu K. Cement-based 0–3 piezoelectric composites. J. Am. Ceram. Soc., 2002, 85(2): 305.

[25] Pradhan D.K., Choudhary R.N.P., Samantaray B.K. Studies of dielectric relaxation and AC conductivity behavior of plasticized polymer nanocomposite electrolytes. Int. J. Electrochem. Sci., 2008, 3, 597.