AICAR Inorganic polymers otherwise known as geopolymers are

Inorganic polymers, otherwise known as geopolymers, are becoming increasingly interesting as a feasible means of reducing world pollution by the possibility of their replacing conventional cements, plastics and many mineral based products, since their production reduces CO2 emissions and can also be based upon recycled materials [1], [2], [3] and [4]. Natural aluminosilicate AICAR such as kaolinites can typically be used as raw materials to synthesize geopolymers [5] and [6]. Geopolymers are X-ray amorphous materials consisting of a network of SiO4 and AlO4 tetrahedra linked randomly by sharing their oxygen atoms. In this configuration, each AlO4 tetrahedron introduces a negative charge which is balanced by an alkali metal cation [7]. Geopolymer synthesis involves reactions between a reactive solid aluminosilicate powder and a concentrated caustic alkali metal silicate solution, yielding a tri-dimensional poly(sialate) at ambient temperatures. The molecular structure and hence the properties of the geopolymer depends on parameters such as the chemical and mineralogical compositions of the solid aluminosilicate source, its dissolution properties, the composition and amount of alkali activator, and the curing conditions. Of sapwood parameters, the chemical composition of both the solid raw material and the activating solution is very important in determining the molecular structure of the final product. The chemical composition of such cementitious systems can be defined by the molar ratios of SiO2/Al2O3, SiO2/Na2O, Na2O/Al2O3, and H2O/Al2O3[6], [8], [9] and [10].