Geopolymers for Structural Ceramic Applications

"Ceramic polymers or "geopolymers" are amorphous to semi-crystalline three dimensional alumino-silicate materials resulting from geochemistry. "Geopolymerisation" is the chemical reaction between various aluminosilicate oxides (Al+3 in Iv, V, or Vi foldcoordination) with silicates under highly alkaline conditions, yielding polymeric Si-O-Al-O bonds (HUA & VanDeventer 1999). Geopolymers form co-polymerisation of individual alumino and silicate species, which originate from materials containing hostsources of either silicon, aluminum or combinations of the foregoing. In order to form geopolymer chains, rings or complete tetrahedral, positive ions such as K, Na, Ca, Ba, Nhy, H30 (etc) must be present in the framework in order to balance the negativecharge of Al.Differing chain and ring structures form at different Si: Al ratios. Polymeric structures are generally formed when the Si:Al ratio is greater than 3. From this polysilicate chains can form 3-dimensional cross-linked structures. It is this cross-linkingphenomenon which facilitates the ability to enhance the standard characteristics of traditional ceramics yielding ceramic polymers (geopolymers)which are characterized by: high compressive strengths, higher tensile strengths, flexibility, ductility andwear harden ability, high surface hardness and the ability to adhere to metals. Programs such as STTR will aid the company in maintaining a technologic lead in a world wide emerging technology-ceramic polymers. Through it's association withTundra-Geo-Technologies Ltd.; Catawba has the ability to attract capital for further future development. In this Phase I program, Catawba is contributing all chemicals necessary in this program at no cost to the program."