Details
| Original language | English |
|---|---|
| Pages (from-to) | 18499-18508 |
| Number of pages | 10 |
| Journal | Ceramics international |
| Volume | 44 |
| Issue number | 15 |
| Early online date | 9 Jul 2018 |
| Publication status | Published - 15 Oct 2018 |
| Externally published | Yes |
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.
Keywords
- Cameroon clay, Compressive strength, Durability, Geopolymerization, Influence ratio Na/Al, Meta-halloysite
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Materials Science(all)
- Ceramics and Composites
- Chemical Engineering(all)
- Process Chemistry and Technology
- Materials Science(all)
- Surfaces, Coatings and Films
- Materials Science(all)
- Materials Chemistry
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In: Ceramics international, Vol. 44, No. 15, 15.10.2018, p. 18499-18508.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Synthesis and properties of inorganic polymers (geopolymers) derived from Cameroon-meta-halloysite
AU - Kaze, Cyriaque Rodrigue
AU - Tchakoute, Herve Kouamo
AU - Mbakop, Theophile Tchakouteu
AU - Mache, Jacques Richard
AU - Kamseu, Elie
AU - Melo, Uphie Chinje
AU - Leonelli, Cristina
AU - Rahier, Hubert
N1 - Funding Information: Rodrigue Cyriaque Kaze gratefully acknowledges Ingessil Srl, Verona, Italy, for providing sodium silicate used for these investigations. This project received the contribution of the World Academy of Sciences for the Third World, TWAS, through the funding 15-079 RG/CHE/AF/AC_I to Dr. Elie Kamseu.
PY - 2018/10/15
Y1 - 2018/10/15
N2 - 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.
AB - 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.
KW - Cameroon clay
KW - Compressive strength
KW - Durability
KW - Geopolymerization
KW - Influence ratio Na/Al
KW - Meta-halloysite
UR - http://www.scopus.com/inward/record.url?scp=85049739826&partnerID=8YFLogxK
U2 - 10.1016/j.ceramint.2018.07.070
DO - 10.1016/j.ceramint.2018.07.070
M3 - Article
AN - SCOPUS:85049739826
VL - 44
SP - 18499
EP - 18508
JO - Ceramics international
JF - Ceramics international
SN - 0272-8842
IS - 15
ER -