Recent Advances in Ionic Liquid-Mediated SO₂ Capture

Abstract

The capture of SO 2 from flue gases is a worldwide concern, which is closely related to environmental, economical, and technological issues. Ionic liquids (ILs), as a kind of promising acidic gas absorbent, have been attracting increasing attention for innovative SO 2 capture approaches recently, burgeoning in the literature. In this paper, we give an overview of the relevant current progress on IL-mediated SO 2 capture, focusing on promising strategies of improving SO 2 absorption capacity, reducing desorption enthalpy, the design of green IL absorbents, and technologies of SO 2 / CO 2 selective capture, eutectic ILs, supported ILs, and IL membranes, based on depiction of the corresponding SO 2 absorption mechanism.

Ionic Liquid‐Based Stimuli‐Responsive Functional Materials

“…Additionally, ILs have been attracting increasing attention for innovative SO 2 detection and capture approaches. [ 62 ] A novel anion‐functionalized fluorescent ionic liquid ([P 66614 ][HBO]) was synthesized by the acid–base neutralization between 2‐(2′‐hydroxyphenyl)benzoxazole and a solution of phosphonium hydroxide in ethanol, which was capable of capturing sulfur dioxide with high capacity and could also be used as a good colorimetric SO 2 sensor. [ 63 ] Compared to conventional fluorescent sensors, this fluorescent ionic liquid did not undergo aggregation caused quenching or aggregation‐induced emission, but the fluorescence was quenched when exposed to SO 2 .…”

“…Thus, the fluorescence of the [HBO‐SO 2 ] − ‐SO 2 anion was quenched due to the strong ICT interaction, while the fluorescence of the [HBO‐SO 2 ] − anion remained because no obvious charge transfer occurred. [ 62 ]…”

“…Thus, the fluorescence of the [HBO-SO 2 ] − -SO 2 anion was quenched due to the strong ICT interaction, while the fluorescence of the [HBO-SO 2 ] − anion remained because no obvious charge transfer occurred. [62] Recently, a class of highly cross-linked nonporous poly(ionic liquid)s xerogels is prepared with high ionic density by photopolymerization of Gemini IL monomers. (1, 6- 4 ), but exhibit very high SO 2 adsorption capacity (498 mg g −1 ) via selective swelling mechanism.…”

The crystal structure of 3,3′-((carbonylbis(azanediyl))bis(ethane-2,1-diyl)) bis(1-methyl-1H-benzo[d]imidazol-3-ium) tetrafluoroborate monohydrate, C21H28N6O3B2F8

“…Ionic liquids are salts that can melt at temperatures below 100°C and are typically composed of large and unsymmetrical organic cations and organic or inorganic anions [7]. ILs have been recognized as new green solvents for chemical reactions [8], extractions [9], catalysis [10], gas absorption [11], and promising candidate materials for electrolytes in electrochemical devices [12]. The asymmetric unit of the title compound contains one half of a bisbenzimidazolium diaction, one tetrafluoroborate anion and water molecules near to a two-fold axis with an occupancy of 0.5 (see the Figure), and lattice water was omitted for clarity.…”

Room temperature ionic liquid promoted improved and rapid synthesis of highly functionalized imidazole and evaluation of their inhibitory activity against human cancer cells

“…Moreover, room‐temperature ionic liquids (RTILs) 29,30 are liquids consisting entirely of ions, and their important properties. e.g., high thermal stability, excellent chemical stability, negligible vapor pressure, extensive liquid temperature assortment, easy recyclability, and reliable solvent supremacy for a wide variety of inorganic and organic compounds by remodeling of anions and cations, the characteristics of ionic liquids can be derived in several ways up to the present time, 31–34 and several functional ionic liquids have been prepared for various purposes 35,36 . Particularly, they have been extensively useful in organic/inorganic transformations as catalysts or solvents, mostly including michael's reaction, 37 aldol reaction, 38 Knoevenagel condensation, 39 coupling reaction, 40 Diels−Alder reaction, 41 oxidation, 42 and reduction 43 …”