Physical properties and microstructures of poly(phospho-siloxo) and poly(sialate-siloxo) networks from two metakaolins


The aim of this investigation is to compare the properties of poly(phospho-siloxo) and poly(sialate-siloxo) networks. Commercial sodium waterglass and sodium waterglass from rice husk ash were used as alkaline reagents and phosphoric acid with molarities 8 and 10 M was used as acid reagents. Local metakaolin and commercial ones containing 0.99 and 0.0% of Fe2O3, respectively, were used as aluminosilicate sources. The physical properties of the prepared poly(phospho-siloxo) and poly(sialate-siloxo) networks were monitored by measuring the apparent and absolute density. The microstructures were assessed by scanning electron microscopy and mercury intrusion porosimetry. The engineering property was checked by the determination of their compressive strengths. The results indicated that the apparent densities of poly(phospho-siloxo) and poly(sialate-siloxo) networks are in the ranges 1.918–2.177 and 1.814–1.959 g/cm3, respectively, while their absolute densities are not significantly different. Their compressive strengths are ranging from 14.21 to 30.03 and 50.22 to 75.77 MPa, respectively. The average pore diameters of the specimens from acid reagents are between 30.0 and 83.9 nm whereas those from alkaline reagents are between 8.3 and 14.8 nm. The log differential intrusion versus pore size diameters showed that the obtained products using acid and alkaline solutions are ranging from 6000 to 110,000 nm and 5.59 to 13.84 nm, respectively. This indicates that poly(phospho-siloxo) and poly(sialate-siloxo) networks are macroporous and mesoporous materials, respectively. It was found that the chemical and mineralogical compositions and the degree of the purity of the aluminosilicate source could significantly affect the physical properties and microstructures of poly(phospho-siloxo) network.

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  1. 1.

    J.G.S. van Jaarsveld, J.S.J. van Deventer, G.C. Lukey, The effect of composition and temperature on the properties of fly ash- and kaolinite-based geopolymers. Chem. Eng. J. 89, 63–73 (2002)

    Article  Google Scholar 

  2. 2.

    A. Elimbi, H.K. Tchakouté, D. Njopwouo, Effects of calcination temperature of kaolinite clays on the properties of geopolymers cements. Constr. Build. Mater. 25, 2805–2812 (2011)

    Article  Google Scholar 

  3. 3.

    R. Lloyd, J. Provis, S.J.S. Van Deventer , Pore solution composition and alkali diffusion in inorganic polymer cement. Cement Concr. Res. 40, 1386–1392 (2010)

    CAS  Article  Google Scholar 

  4. 4.

    N. Hamdi, I. Ben Messaoud, E. Srasra, Production of geopolymer binders using clay minerals and industrial wastes. Compt. Rendus Chem. 22, 220–226 (2019)

    CAS  Article  Google Scholar 

  5. 5.

    D. Cao, D. Su, B. Lu, Y. Yang, Synthesis and structure characterization of geopolymeric material based on metakaolinite and phosphoric acid. J. Chinese Ceram. Soc. 33, 1385–1389 (2005)

    CAS  Google Scholar 

  6. 6.

    D.S. Perera, J.V. Hanna, J. Davis, The relative strength of phosphoric acid-reacted and alkali-reacted metakaolin materials. J. Mater. Sci. 43, 6562–6566 (2008)

    CAS  Article  Google Scholar 

  7. 7.

    L. Le-ping, C. Xue-min, Q. Shu-heng, Y. Jun-li, Z. Lin, Preparation of phosphoric acid-based porous geopolymers. Appl. Clay Sci. 50, 600–603 (2010)

    Article  Google Scholar 

  8. 8.

    H. Douiri, S. Louati, S. Baklouti, M. Arous, Z. Fakhfakh, Structural, thermal and dielectric properties of phosphoric acid-based geopolymers with different amounts of H3PO4. Mater. Lett. 116, 9–12 (2014)

    CAS  Article  Google Scholar 

  9. 9.

    S. Louati, W. Hajjaji, S. Baklouti, B. Samet, Structure and properties of new eco-material obtained by a phosphoric acid attack of natural Tunisian clay. Appl. Clay Sci. 101, 60–67 (2014)

    CAS  Article  Google Scholar 

  10. 10.

    S. Louati, W. Hajjaji, S. Baklouti, B. Samet, Acid based geopolymerization kinetics: effect of clay particle size. Appl. Clay Sci. 132–133, 571–578 (2016)

    Article  Google Scholar 

  11. 11.

    S. Louati, W. Hajjaji, S. Baklouti, B. Samet, Geopolymers based on phosphoric acid and illito-kaolinitic clay. Adv. Mater. Sci. Eng. (2016).

    Article  Google Scholar 

  12. 12.

    C. Guo, K. Wang, M. Liu, X. Li, X. Cui, Preparation and characterization of acid-based geopolymer using metakaolin and disused polishing liquid. Ceram. Inter. 42, 9287–9291 (2016)

    CAS  Article  Google Scholar 

  13. 13.

    H.K. Tchakouté, C.H. Rüscher, E. Kamseu, J.N.Y. Djobo, C. Leonelli, The influence of gibbsite in kaolin and the formation of berlinite on the properties of metakaolin-phosphate-based geopolymer cements. Mater. Chem. Phys. 199, 280–288 (2017)

    Article  Google Scholar 

  14. 14.

    M. Khabbouchi, K. Hosni, M. Mezni, C. Zanelli, M. Doggy, M. Dondi, E. Srasra, Interaction of metakaolin-phosphoric acid and their structural evolution at high temperature. Appl. Clay Sci. 146, 510–516 (2017)

    CAS  Article  Google Scholar 

  15. 15.

    M. Khabbouchi, K. Hosni, M. Mezni, E. Srasra, Simplified synthesis of silicophosphate materials using an activated metakaolin as a natural source of active silica. Appl. Clay Sci. 158, 169–176 (2018)

    CAS  Article  Google Scholar 

  16. 16.

    V. Mathivet, J. Jouin, A. Gharzouni, I. Sobrados, H. Celerier, S. Rossignol, M. Parlier, Acid-based geopolymers: understanding of the structural evolutions during consolidation and after thermal treatments. J. Non-Cryst. Solids 512, 90–97 (2019)

    CAS  Article  Google Scholar 

  17. 17.

    C.N. Bewa, H.K. Tchakouté, C.H. Rüscher, E. Kamseu, C. Leonelli, Influence of the curing temperature on the properties of poly(phospho-ferro-siloxo) networks from laterite. SN Appl. Sci. 1, 1–12 (2019)

    Article  Google Scholar 

  18. 18.

    H. Celerier, J. Jouin, V. Mathivet, N. Tessier-Doyen, S. Rossignol, Composition and properties of phosphoric acid-based geopolymers. J. Non-Cryst. Solids 493, 94–98 (2018)

    CAS  Article  Google Scholar 

  19. 19.

    A. Katsiki, T. Hertel, T. Tysmans, Y. Pontikes, H. Rahier, Metakaolinite phosphate cementitious matrix: inorganic polymer obtained by acidic activation. Mater. 12, 442 (2019)

    CAS  Article  Google Scholar 

  20. 20.

    J. Davidovits, Geopolymer Chemistry and Applications, 3rd edn. (Institute Geopolymer, Saint-Quentin, 2011), p. 612

    Google Scholar 

  21. 21.

    L.P. Liu, X.M. Cui, Y. He, S.D. Liu, S.Y. Gong, The phase evolution of phosphoric acid-based geopolymers at elevated temperatures. Mater. Lett. 66, 10–12 (2012)

    CAS  Article  Google Scholar 

  22. 22.

    M.S. Morsy, A.M. Rashad, H. Shoukry, M.M. Mokhtar, Potential use of limestone in metakaolin-based geopolymer activated with H3PO4 for thermal insulation. Construct. Build. Mater. 22, 117088 (2019)

    Article  Google Scholar 

  23. 23.

    Z. Zuhua, Y. Xiao, Z. Huajun, C. Yue, Role of water in the synthesis of calcined kaolin-based geopolymer. Appl. Clay Sci. 43, 218–223 (2009)

    CAS  Article  Google Scholar 

  24. 24.

    J. Temuujin, A. Minjigmaa, W. Rickard, A. van Riessen, Thermal properties of spray-coated geopolymer-type compositions. J. Therm. Anal. Calorim. 107, 287–292 (2012)

    CAS  Article  Google Scholar 

  25. 25.

    Y. Fang, O. Kayali, The fate of water in fly ash-based geopolymers. Constr. Build. Mater. 39, 89–94 (2013)

    Article  Google Scholar 

  26. 26.

    S.J.K. Melele, H.K. Tchakouté, C. Banenzoué, E. Kamseu, C.H. Rüscher, F. Andreola, C. Leonelli, Investigation of the relationship between the condensed structure and the chemically bonded water content in the poly(sialate-siloxo) network. Appl. Clay Sci. 156, 77–86 (2018)

    CAS  Article  Google Scholar 

  27. 27.

    H.K. Tchakouté, C.H. Rüscher, E. Kamseu, F. Andreola, C. Leonelli, Influence of the molar concentration of phosphoric acid solution on the properties of metakaolin-phosphate-based geopolymer cements. Appl. Clay Sci. 147, 184–194 (2017)

    Article  Google Scholar 

  28. 28.

    H.K. Tchakouté, C.H. Rüscher, Mechanical and microstructural properties of metakaolin-based geopolymer cements from sodium waterglass and phosphoric acid solution as hardeners: a comparative study. Appl. Clay Sci. 140, 81–87 (2017)

    Article  Google Scholar 

  29. 29.

    E. Kamseu, B. Nait-Ali, M.C. Bignozzi, C. Leonelli, S. Rossignol, D.S. Smith, Bulk composition and microstructure dependence of effective thermal conductivity of porous inorganic polymer cements. J. Eur. Ceram. Soc. 32, 1593–1603 (2012)

    CAS  Article  Google Scholar 

  30. 30.

    M.L. Gualtieri, M. Romagnoli, S. Pollastri, A.F. Gualtieri, Inorganic polymers from laterite using activation with phosphoric acid and alkaline sodium silicate solution: Mechanical and microstructural properties. Cem. Concr. Res. 67, 259–270 (2015)

    Article  Google Scholar 

  31. 31.

    H.K. Tchakouté, C.H. Rüscher, J.N.Y. Djobo, B.B.D. Kenne, D. Njopwouo, Influence of gibbsite and quartz in kaolin on the properties of metakaolin-based geopolymer cements. Appl. Clay Sci. 107, 188–194 (2015)

    Article  Google Scholar 

  32. 32.

    H.K. Tchakouté, C.H. Rüscher, S. Kong, E. Kamseu, C. Leonelli, Comparison of metakaolin-based geopolymer cements from commercial sodium waterglass and sodium waterglass from rice husk ash. J. Sol Gel Sci. Techn. 78, 492–506 (2016)

    Article  Google Scholar 

  33. 33.

    D.E.T. Mabah, H.K. Tchakouté, C.H. Rüscher, E. Kamseu, A. Elimbi, C. Leonelli, Design of low-cost semi-crystalline calcium silicate from biomass for the improvement of the mechanical and microstructural properties of metakaolin-based geopolymer cements. Mater. Chem. Phys. 223, 98–108 (2019)

    Article  Google Scholar 

  34. 34.

    D.E.T. Mabah, H.K. Tchakouté, D. Fotio, C.H. Rüscher, E. Kamseu, M.C. Bignozzi, C. Leonelli, Influence of the molar ratios CaO/SiO2 contained in the sustainable microcomposites on the mechanical and microstructural properties of (Ca, Na)-poly(sialate-siloxo) networks. Mater. Chem. Phys. 238, 121928 (2019)

    CAS  Article  Google Scholar 

  35. 35.

    H.K. Tchakouté, C.H. Rüscher, S. Kong, E. Kamseu, C. Leonelli, Geopolymer binders from metakaolin using sodium waterglass from waste glass and rice husk ash as alternative activators: a comparative study. Constr. Build. Mater. 114, 276–289 (2016)

    Article  Google Scholar 

  36. 36.

    H.K. Tchakouté, C.H. Rüscher, S. Kong, N. Ranjbar, Synthesis of sodium waterglass from white rice husk ash as an activator to produce metakaolin-based geopolymer cements. J. Build. Eng. 6, 252–261 (2016)

    Article  Google Scholar 

  37. 37.

    M. Zribi, B. Samet, S. Baklouti, Effect of curing temperature on the synthesis, structure and mechanical properties of phosphate-based geopolymers. J. Non-Cryst. Solids 511, 62–67 (2019)

    CAS  Article  Google Scholar 

  38. 38.

    L. Gao, Y. Zheng, Y. Tang, J. Yu, X. Yu, B. Liu, Effect of phosphoric acid content on the microstructure and compressive strength of phosphoric acid-based metakaolin geopolymers. Heliyon 6, e03853 (2020)

    Article  Google Scholar 

  39. 39.

    C.N. Bewa, H.K. Tchakouté, D. Fotio, C.H. Rüscher, E. Kamseu, C. Leonelli, Water resistance and thermal behavior of metakaolin-phosphate-based geopolymer cements. J. Asian Ceram. Soc. 6, 271–283 (2018)

    Article  Google Scholar 

  40. 40.

    C.A. Rees, J.L. Provis, G.C. Lukey, J.S.J. van Deventer, In situ ATR-FTIR study of the early stages of fly ash geopolymer gel formation. Langmuir 23, 9076–9082 (2007)

    CAS  Article  Google Scholar 

  41. 41.

    J. He, J.H. Zhang, Y.Z. Yu, G.P. Zhang, The strength and microstructure of two geopolymers derived from metakaolin and red mud-fly ash admixture: a comparative study. Constr. Build. Mater. 30, 80–91 (2012)

    Article  Google Scholar 

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Dr. Tchakouté Kouamo Hervé gratefully acknowledges the Alexander von Humboldt Foundation for its financial support to this work under grant N° KAM/1155741 GFHERMES-P. The authors would like to thank Mr Valerie Petrov for SEM observations.

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CB: Participle to the conception of the project, methodology, resources, writing the first draft of the manuscript, data curation and answer to the reviewers comments. CNB: Methodology, formal analysis and data curation. DF: Formal analysis, investigation, data curation. HKT: Conceptualization, formal analysis, funding acquisition, investigation, methodology, resources, writing-original draft, writing-review and editing. BTT: Methodology, formal analysis, data curation. CHR: Project administration, formal analysis, resources, supervision, validation, visualization, data curation.

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Banenzoué, C., Bewa, C.N., Fotio, D. et al. Physical properties and microstructures of poly(phospho-siloxo) and poly(sialate-siloxo) networks from two metakaolins. J. Korean Ceram. Soc. 58, 452–470 (2021).

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  • Metakaolins
  • Sodium waterglass
  • Phosphoric acid
  • Poly(sialate-siloxo)
  • Poly(phospho-siloxo)
  • Microstructures