Inorganic polysialates or 'geopolymers'

Polysialates or geopolymers are a relatively new ceramic-like material that is starting to draw attention outside a community of specialized researchers for its unusual properties, strength and environmental impact. Besides being greener, geopolymers are strong, lightweight and quick setting. Geopolymers are a type of inorganic polymeric ceramic formed from aluminum and silicon sources that contain AlO₄ and SiO₄ tetrahedral units, under highly alkaline conditions at ambient temperatures. Geopolymer is usually formed by mixing a liquid (waterglass) with an aluminosilicate powder to form a paste. Because of the low-temperature synthesis route at ambient temperatures, a variety of reinforcements can be added to make geopolymer composites. Geopolymers could be employed as refractory adhesives for glass, some ceramics and some metals, including stainless steel. The porous properties could be targeted for insulators and refractories, porous chemical and water filters, and filter supports for CO2 sequestration.