A novel TiO2/Epoxy resin composited geopolymer with great durability in wetting-drying and phosphoric acid solution. (1st August 2019)

• Record Type: Journal Article
• Authors: Ren, Jie; Guo, Si-Yao; Su, Jie; Zhao, Tie-Jun; Chen, Ji-Zhou; Zhang, Su-Lei
• Is Part Of: Journal of cleaner production. Volume 227(2019)
• Page Start: 849
• Page End: 860
• Publication Date: 2019-08-01
• Subjects: TiO2/Epoxy resin composite -- Wetting-drying cycles -- Alkali-activated slag/fly ash (AASF) geopolymer -- Phosphoric acid -- Durability; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2019.04.203
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: A novel hybrid structured TiO2 /Epoxy resin has been prepared by a simple in-situ synthetic method, which was used to enhance alkali-activated slag/fly ash (AASF) geopolymer paste for the first time. The study examined the durability performance of the paste by exposing specimens to two aggressive conditions, including wetting-drying cycles and continuous immersions in phosphoric acid solutions for 90 days. Visual appearances, physical, mechanical properties and microstructures of samples were analysed. Besides, degradation kinetics were monitored by measuring degradation depths. The results indicate that TiO2 /Epoxy resin composite is able to improve the microstructures and limit the propagation of cracks. It is assumed that the hydroxyl groups of the epoxy resin and the bonded water in the aluminosilicate gel may form hydrogen bonds which make the binder matrix dense and homogeneous. The matrix thus intrinsically has a better fracture behavior with the existence of organic-based TiO2 /Epoxy resin compared to the inorganic-based aluminosilicate crosslinked networks. The study also revealed that compared to the AASF without the composite addition, TiO2 /Epoxy resin composited AASF exhibited a lower degradation kinetic regardless of exposure conditions. Therefore, a new direction is developed and recommended to use TiO2 /Epoxy resin to improve the durability of AASF geopolymer regarding aggressive exposure environments. In addition, the manufacturing of TiO2 /Epoxy resin composited AASF binder is relatively simple, cost-effective and eco-friendly with low carbon footprint. Graphical abstract: Image 102280341 Highlights: A novel nano-TiO2 /Epoxy resin composite was prepared and added into a geopolymer paste to enhance its durability. The TiO2 /Epoxy resin enhanced geopolymer paste obtained a higher durability than the control paste. The TiO2 /Epoxy resin composited geopolymer paste is compact and able to limit the propagations of cracks. The wetting-drying condition is more aggressive than the continuous exposure condition.