1. Center of Excellence Geopolymer and Green Technology (CEGeoGTech)School of Materials Engineering, Universiti Malaysia Perlis 02600 Arau Perlis Malaysia
2. School of Fundamental ScienceUniversiti Malaysia Terengganu 21030 Kuala Terengganu Terengganu Malaysia
3. Department of Chemistry, Environmental Materials & Analytical Chemistry LaboratoryIndian Institute of Technology Kharagpur 721302 West Bengal India