Recent Advances in Poly(Ionic Liquid)-Based Membranes for CO2 Separation

Abstract

Poly(ionic liquid)-based membranes have been the subject of intensive research in the last 15 years due to their potential for the separation of CO2 from other gases. In this short review, different types of PIL-based membranes for CO2 separation are described (neat PIL membranes; PIL-IL composite membranes; PIL-polymer blend membranes; PIL-based block copolymer membranes, and PIL-based mixed matrix membranes), and their state-of-the-art separation results for different gas pairs (CO2/N2, CO2/H2, and CO2/CH4) are presented and discussed. This review article is focused on the most relevant research works performed over the last 5 years, that is, since the year 2017 onwards, in the field of poly(ionic liquid)-based membranes for CO2 separation. The micro- and nano-morphological characterization of the membranes is highlighted as a research topic that requires deeper study and understanding. Nowadays there is an array of advanced structural characterization techniques, such as neutron scattering techniques with contrast variation (using selective deuteration), that can be used to probe the micro- and nanostructure of membranes, in length scales ranging from ~ 1 nm to ~ 15 mm. Although some of these techniques have been used to study the morphology of PIL-based membranes for electrochemical applications, their use in the study of PIL-based membranes for CO2 separation is still unknown.

Anionic Glycidyl Triazolyl Polymers: Oppositely Charged Analogs of Imidazolium-Based Cationic Glycidyl Triazolyl Polymers

“…Poly­(ionic liquid)­s are soft, lightweight, and safe (no risk of leakage and fire) electrolytes; − hence, they are promising functional materials in many fields, including energy-storage materials, electrochromic devices, actuators, CO 2 separation, adaptive materials, and stimuli-responsive materials . Owing to their diverse application fields, many research groups continue the quest for new molecular design for modulating the physical properties. − ,− In order to elucidate the structure–property relationship of poly­(ionic liquid)­s, high-molecular-weight poly­(ionic liquid)­s must be prepared because their physical properties are strongly dependent on the molecular weight when it is below 10 5 g mol –1 .…”

“…Poly(ionic liquid)s are soft, lightweight, and safe (no risk of leakage and fire) electrolytes; 1−4 hence, they are promising functional materials in many fields, including energy-storage materials, 5 electrochromic devices, 6 actuators, 7 CO 2 separation, 8 adaptive materials, 9 and stimuli-responsive materials. 10 Owing to their diverse application fields, many research groups continue the quest for new molecular design for modulating the physical properties.…”