Geopolymer: A Review on Physical Properties of Inorganic Aluminosilicate Coating Materials

Geopolymer is a potential material that can be used in many forms of applications such as for building, automotive, aerospace, and many more. It exhibits many excellent physical, thermal and chemical properties. Geopolymer material provides a cost effective and sustainable solution by recycle the hazardous residue material and it undergone green chemistry technique treatment. Geopolymerization process involves combination mixture of aluminosilicate from natural mineral or industrial waste such as fly ash or slag or rice husk ash with activated alkaline solution. This review paper exclusively explore more on the interfacial adhesion of geopolymer coating on substrate surface, effect of coating thickness and filler inclusion in geopolymer matrix system. Literature demonstrates that type of substrate and substrate surface plays a crucial role for good interfacial adhesion with geopolymer materials. In addition, coating thickness will affect the insulating capacity performance, while inclusion of filler can reduce the coating shrinkage problem.

Characterization of Aluminosilicate Formation on the Surface of a Crystalline Silicotitanate Ion Exchanger

Millions of gallons of high-level radioactive waste are contained in underground tanks at U. S. Department of Energy sites such as Hanford and Savannah River. Most of the radioactivity is due to 137Cs and 90Sr, which must be extracted in order to concentrate the waste. An ion exchanger, crystalline silicotitanate IONSIV® IE911, is being considered for separation of Cs at the Savannah River Site (SRS). While the performance of this ion exchanger has been well characterized under normal operating conditions, Cs removal at slightly elevated temperatures, such as those that may occur in a process upset, is not clear. Our recent study indicates that during exposure to SRS simulant at 55°C and 80°C, an aluminosilicate coating formed on the exchanger surface. There was concern that the coating would affect its ion exchange properties. A LEO 982 field emission scanning electron microscope (FESEM) and an Oxford ISIS energy dispersive x-ray spectrometer (EDS) were used to characterize the coating.