Chitin-acetate/DMSO as a supramolecular green CO₂-phile

Abstract

The supramolecular chemisorption of CO2 by the oligosaccharide chitin-acetate (CA) in DMSO as a green, binary sorbent-based system offers a potential, novel and eco-friendly approach for post combustion capture applications.

An investigation of carbon dioxide capture by chitin acetate/DMSO binary system

“…However, DMSO (Figure 4C), which acts as a hydrogen bond acceptor, activated the hydroxyl group to become more susceptible towards nucleophilic attack, which is a prerequisite to CO2 capturing. This was previously indicated by our group using 13 C NMR of CA in deuterated dimethyl sulfoxide (DMSO-d6) (Eftaiha et al, 2016). Upon bubbling CO2, two peaks emerged at 124.7 and 157.4 ppm, which were ascribed to physically dissolved CO2 in DMSO, and the newly formed alkylcarbonate peak, respectively.…”

“…Moreover, the observed red shift in the (C=O) peak of acetate anion centered at 1715 cm -1 supports the metathesis of ammonium-acetate into ammonium-carbonate upon chemisorption of CO2. This was supported by conductivity measurements as reported by our previous work (Eftaiha et al, 2016).…”

“…In order to gather more insights to ultimately understand the mechanism involved, further elaborated studies were required. To our knowledge, our finding was a first report with solid evidence on the chemisorption of CO2 by oligomeric chitin rather than presumed physical interactions with the polymeric material dissolved in ionic liquids (ILs) (Xie et al, 2006;Eftaiha et al, 2016).…”

“…Their sorbents proved to be active towards CO2 capturing with a highly reversible character which is considered as a pre-requisite for postcombustion capturing. Very recently, we explored the interaction between an oligomeric form of chitin, viz., chitin-acetate (CA) using dimethyl sulfoxide (DMSO) as a solvent with CO2 at ambient temperature and pressure (Eftaiha et al, 2016). Our results indicated that the hydroxyl based oligosaccharide captures CO2 through the formation of an organic carbonate species.…”

“…The formation of alkylcarbonate upon bubbling CO2 into CA dissolved in DMSO was further verified using in situ ATR-FTIR spectroscopy (Eftaiha et al, 2016). Upon bubbling, a new peak appeared at 1555 cm -1 that can be ascribed to the stretching mode of carbonate (Song & Baek, 2009).…”