eprintid: 6012 rev_number: 2 eprint_status: archive userid: 1 dir: disk0/00/00/60/12 datestamp: 2023-11-09 16:17:45 lastmod: 2023-11-09 16:17:45 status_changed: 2023-11-09 16:04:33 type: article metadata_visibility: show creators_name: Irfan Khan, M. creators_name: Azizli, K. creators_name: Sufian, S. creators_name: Man, Z. title: Sodium silicate-free geopolymers as coating materials: Effects of Na/Al and water/solid ratios on adhesion strength ispublished: pub keywords: Adhesion; Bond strength (materials); Chemical stability; Coal ash; Coatings; Corrosion resistant coatings; Fire resistance; Fly ash; Fourier transform infrared spectroscopy; Geopolymers; Inorganic polymers; Microstructure; Plating; Silicates; Thermodynamic properties; Zeolites, Anti-corrosion property; Chemical compositions; Coating formulations; Fibrous morphology; Geopolymer; Microstructural investigation; Polymeric structures; Temper resistance, Sodium compounds note: cited By 77 abstract: Geopolymer-based coatings exhibit good fire inhibition, temper resistance, and anticorrosion properties. In this study, coal fly ash-based geopolymers were investigated as coating materials. Two variables, namely, Na/Al and water/solid ratios, were used to study the effect of the chemical composition of geopolymer on adhesion strength, setting time, microstructure, and thermal stability (up to 800 °C). Maximum adhesion strength (3.8 MPa) was achieved using Na/Al and water/solid ratios of 1.0 and 0.33, respectively. The coatings attained their maximum strength in 3 days at 60 °C, and additional curing time up to 6 months did not affect adhesion strength. No direct or indirect relationship was found between setting time and adhesion strength. The amount of water notably altered adhesion strength, setting time, and microstructure of the polymers. Microstructural investigations revealed formation of mesoporous polymeric structure, unreacted fly ash, and zeolite-like fibrous morphologies. A new and simple method for the quantitative analysis of geopolymer was developed using Fourier transform infrared spectroscopy (FTIR). FTIR peak-fitting method showed that geopolymer yield was between 50 and 70, which was comparable to the result of acid-leaching method. The coating formulations were thermally inactive up to 800 °C with a mass loss of 11-12 mostly because of dehydroxylation. Na/Al and water/solid ratios had no effect on the thermal properties of the geopolymer. © 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved. date: 2015 publisher: Elsevier Ltd official_url: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84919462253&doi=10.1016%2fj.ceramint.2014.10.099&partnerID=40&md5=29e3707fc8520fd78b811679d6b028e6 id_number: 10.1016/j.ceramint.2014.10.099 full_text_status: none publication: Ceramics International volume: 41 number: 2 pagerange: 2794-2805 refereed: TRUE issn: 02728842 citation: Irfan Khan, M. and Azizli, K. and Sufian, S. and Man, Z. (2015) Sodium silicate-free geopolymers as coating materials: Effects of Na/Al and water/solid ratios on adhesion strength. Ceramics International, 41 (2). pp. 2794-2805. ISSN 02728842