CO2 capture and conversion by an organosilane-modified cementitious material. (30th August 2020)

• Record Type: Journal Article
• Authors: Qu, Min; Liu, Peng; Zhao, Du; Wang, Fazhou; Hu, Chuanlin; Zhao, Cheng
• Is Part Of: Construction & building materials. Volume 253(2020)
• Publication Date: 2020-08-30
• Subjects: Cementitious material -- CO2 capture -- Fly ash -- Organosiloxane -- Recycle; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2020.119198
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: The fly ash bead was chemically modified by 3-[2-(2-aminoethylamino) ethylamino]propyl-trimethoxysilane. The cement incorporated with TRI-AFA could effectively absorb CO2 from atmosphere. The absorbed CO2 could be converted into CO3 2− via functionalized cement sample. 85% of the sorption capacity was regenerated after 10 cycles. Abstract: Alkali-activated fly ash (AFA) could be modified by 3-[2-(2-aminoethylamino) ethylamino]propyl-trimethoxysilane (TRI). The successful modification of fly ash beads by TRI was confirmed by IR spectra and 29 Si NMR, the TG-DSC results showed that 18.42671 g TRI was loaded on 100 g AFA. The TRI-modified AFA (TRI-AFA) showed strong sorption for CO2, which was confirmed by GC, and it could incorporate into cement to make a new kind of cementitious material. This kind of cementitious material also showed strong sorption for CO2 . Upon immersion of the sample in water, the absorbed CO2 could be converted into CO3 2− due to the alkali environment in the pore solution of the cement, and the sample was then recovered. The recovered sample maintained 85% capacity for CO2 sorption after 10 cycles. Thus, the sample could reversibly absorb and desorb CO2, and could potentially help in reducing greenhouse gases.