Progress in fabrication and manufacturing of sodium aluminosilicate materials (geopolymers) as protective coating materials: A review

Concerns about waste valorization, reduction in greenhouse gases, low energy consumption and zero waste production are arising at faster rate and world now a day’s regularly looking for such material options which not only provide promising properties but also could perform meaningful role in green and sustainable development to unburden environment. Sodium aluminosilicate based geopolymers present class of such materials which encompass green production process and possess massive capacity to enrich building and construction sector by limiting utilization of Portland cement and by providing comparable or even higher properties. Considering versatility of geopolymers in various application sector, in this review we present evocative potential of sodium aluminosilicate based geopolymer as protective coating material for different substrates. In this work we review the long term performance, durability, adhesion and compatibility of geopolymer or geopolymer type cementitious coatings with different type of substrates. History and recent advancement in geopolymer as coating material is also discussed in detail. Different coating techniques like spray coating, brush coating, dipping coating and plasma spray coating are assessed with respect to suitable thickness of the coating. It is shown that the ratios of raw material used, additives and alkalinity are topmost factors in providing corrosion and fire protective properties to the material. This paper briefly reviews recent works on geopolymer coatings and their techno economical and applied feasibility.