Structural and dielectric comparative studies of geopolymers prepared with metakaolin and Tunisian natural clay

Abstract Metakaolin and calcined Tunisian natural clay were used as potential aluminosilicate sources to synthesize phosphoric acid - inorganic polymers known as geopolymers. Structural and dielectric properties of these two kinds of clay were studied. X-ray diffraction patterns showed that the main phases presented for both clays were quartz and illite. Besides, these two specimen showed a great similarity in their dielectric properties in a frequency range [10 2 –10 6 ] Hz. Nevertheless, a dissimilarity was observed at low frequencies [1 − 10 2 ] Hz as a result of the difference in their mineral compositions. In a second time, a comparative study between two geopolymers made of metakaolin and the calcined natural clay was realized. New crystalline phases, produced during geopolymerization reaction were detected in both geopolymers X-ray diffraction patterns. Dielectric results revealed a difference in their dielectric parameters in the low frequency range. It resulted from a variation in charge distribution into the two geopolymer structures. However, for high frequencies a great similarity was observed for both geopolymers.

[1]  J. Deventer,et al.  Geopolymer technology: the current state of the art , 2007 .

[2]  Yan He,et al.  Study on the Dielectric Properties of Phosphoric Acid-Based Geopolymers , 2010 .

[3]  B. Samet,et al.  Acid based geopolymerization kinetics: Effect of clay particle size , 2016 .

[4]  Fabrice Gouny,et al.  A geopolymer mortar for wood and earth structures , 2012 .

[5]  W. Hajjaji,et al.  Structure and properties of new eco-material obtained by phosphoric acid attack of natural Tunisian clay , 2014 .

[6]  M. Arous,et al.  Enhanced dielectric performance of metakaolin–H3PO4 geopolymers , 2016 .

[7]  L. Bonneviot,et al.  The dynamics of water in nanoporous silica studied by dielectric spectroscopy , 2005, The European physical journal. E, Soft matter.

[8]  J. Davidovits.  Geopolymers : inorganic polymeric new materials , 1991 .

[9]  B. Samet,et al.  Study on the potential use of Tunisian clays as pozzolanic material , 2006 .

[10]  Ji Zhou,et al.  A study on electrical conductivity of chemosynthetic Al2O3–2SiO2 geoploymer materials , 2008 .

[11]  A. Soni,et al.  Low frequency dielectric dispersion and microwave permittivities of Indian granites , 2005 .

[12]  A. Soni,et al.  Dielectric properties of some minerals of western Rajasthan , 2008 .

[13]  E. Vance,et al.  Relative strengths of phosphoric acid-reacted and alkali-reacted metakaolin materials , 2008 .

[14]  M. Arous,et al.  Structural, thermal and dielectric properties of phosphoric acid-based geopolymers with different amounts of H3PO4 , 2014 .

[15]  Zhang Lin,et al.  Preparation of phosphoric acid-based porous geopolymers , 2010 .

[16]  Delong Xu,et al.  Mechanical performance and hydration mechanism of geopolymer composite reinforced by resin , 2010 .

[17]  S. Rossignol,et al.  Feasibility of producing geopolymers from two different Tunisian clays before and after calcination at various temperatures , 2014 .

[18]  J. Sangleboeuf,et al.  Thermal behaviour of composites aluminosilicate-calcium phosphates , 2004 .

[19]  Ji Zhou,et al.  A novel aluminosilicate geopolymer material with low dielectric loss , 2011 .