Cameroonian Balengou clay has been characterized as precursor for inorganic polymer (geopolymer) binder. The lowest possible calcination temperature for this halloysite type clay was found to be 600 °C to convert it into meta-halloysite (MH), which is reactive enough for geopolymerization. This implies an energy saving compared to the 800 °C, previously reported in literature. The inorganic polymer has been produced using sodium hydroxide or sodium silicate solutions. A maximum dry compressive strength of 27.5 MPa after 28 days was obtained with a sodium silicate solution [Na2O·1.25SiO2·9.76H2O] resulting in a material with composition: Na2O·3.78SiO2·7.22Al2O3·9.76H2O. This inorganic polymer was amorphous according to XRD, showed a compact microstructure (scanning electron microscopy), with lower values of water absorption, porosity, and higher density. In addition the same composition showed better resistance to 5% sulfuric/hydrochloric solution than the ones made with higher and lower ratio of Na/Al. Meta-halloysite based geopolymers had a 20–30% reduction in strength after immersion in 5% sulfuric/hydrochloric acids for 7 days and even up to 62.5% after 28 days, due to the depolymerisation process of the geopolymer network. The results obtained demonstrated the suitability of Cameroonian meta-halloysite for geopolymer synthesis at room temperature.

Synthesis and properties of inorganic polymers (geopolymers) derived from Cameroon-meta-halloysite / Kaze, C. R.; Tchakoute, H. K.; Mbakop, T. T.; Mache, J. R.; Kamseu, E.; Melo, U. C.; Leonelli, C.; Rahier, H.. - In: CERAMICS INTERNATIONAL. - ISSN 0272-8842. - 44:15(2018), pp. 18499-18508. [10.1016/j.ceramint.2018.07.070]

Synthesis and properties of inorganic polymers (geopolymers) derived from Cameroon-meta-halloysite

Kamseu E.
Conceptualization
;
Leonelli C.
Resources
;
2018

Abstract

Cameroonian Balengou clay has been characterized as precursor for inorganic polymer (geopolymer) binder. The lowest possible calcination temperature for this halloysite type clay was found to be 600 °C to convert it into meta-halloysite (MH), which is reactive enough for geopolymerization. This implies an energy saving compared to the 800 °C, previously reported in literature. The inorganic polymer has been produced using sodium hydroxide or sodium silicate solutions. A maximum dry compressive strength of 27.5 MPa after 28 days was obtained with a sodium silicate solution [Na2O·1.25SiO2·9.76H2O] resulting in a material with composition: Na2O·3.78SiO2·7.22Al2O3·9.76H2O. This inorganic polymer was amorphous according to XRD, showed a compact microstructure (scanning electron microscopy), with lower values of water absorption, porosity, and higher density. In addition the same composition showed better resistance to 5% sulfuric/hydrochloric solution than the ones made with higher and lower ratio of Na/Al. Meta-halloysite based geopolymers had a 20–30% reduction in strength after immersion in 5% sulfuric/hydrochloric acids for 7 days and even up to 62.5% after 28 days, due to the depolymerisation process of the geopolymer network. The results obtained demonstrated the suitability of Cameroonian meta-halloysite for geopolymer synthesis at room temperature.
2018
44
15
18499
18508
Synthesis and properties of inorganic polymers (geopolymers) derived from Cameroon-meta-halloysite / Kaze, C. R.; Tchakoute, H. K.; Mbakop, T. T.; Mache, J. R.; Kamseu, E.; Melo, U. C.; Leonelli, C.; Rahier, H.. - In: CERAMICS INTERNATIONAL. - ISSN 0272-8842. - 44:15(2018), pp. 18499-18508. [10.1016/j.ceramint.2018.07.070]
Kaze, C. R.; Tchakoute, H. K.; Mbakop, T. T.; Mache, J. R.; Kamseu, E.; Melo, U. C.; Leonelli, C.; Rahier, H.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11380/1200528
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