Piperidinium functionalized poly(2,6 dimethyl 1,4 phenylene oxide) based polyionic liquid/ionic liquid (PIL/IL) composites for CO2 separation

Robust anion exchange membranes based on ionic liquid grafted chitosan/polyvinyl alcohol/quaternary ammonium functionalized silica for polymer electrolyte membrane fuel cells

In this study, 1-bromohexyl-1methylpiperidinium bromide (Br-6-MPRD) ionic liquid grafted quaternized chitosan (QCS) and polyvinyl alcohol (PVA) blends were composited with glycidyl trimethyl ammonium chloride (GTMAC) quaternized silica (QSiO2) at different dosages. Glutaraldehyde (GA) crosslinked the membranes and then processed into hydroxide form with an aqueous potassium hydroxide solution. The resultant IL-QCS/PVA/QSiO2 membranes exhibit significantly improved ionic conductivity, moderate water absorption and swelling ratio compared with the pristine IL-QCS/PVA anion exchange membrane (AEM). Among them, the hydroxide ion conductivity and power density of IL-QCS/PVA/QSiO2-7 membrane can reach up to 78 mS cm-1 at 80 °C and 115 mW cm-2 at 60 °C respectively. In addition, IL-QCS/PVA/QSiO2 membranes have excellent thermal, mechanical, and chemical stabilities, which can meet the application requirements of AEM for fuel cells.

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

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 μm. 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.

Ionic Liquid-Acrylic Acid Copolymer Derived Nitrogen-Boron Codoped Carbon-Covered Na3V2(PO4)2F3 as Cathode Material of High-Performance Sodium-Ion Batteries

In this study, a nitrogen-boron codoped carbon layer, Na₃V₂(PO₄)₂F₃ sample, obtained by using an ionic liquid-acrylic acid copolymer as the nitrogen-boron source was used as the cathode material for sodium-ion batteries. The optimized and modified nitrogen and boron codoped carbon layer, Na₃V₂(PO₄)₂F₃ (denoted as NVPF-PCNB-20), illustrated better rate capability and cycling performance. The discharge capacities of NVPF-PCNB-20 at 0.5C and 10C were 109 and 90 mAh g^-1, respectively, and the capacity retention rate was 93.2% after 100 cycles at 0.5C and 92.8% after 750 cycles at 10C. Through in situ X-ray diffraction analysis of NVPF-PCNB-20, the results show that the modified Na₃V₂(PO₄)₂F₃ has excellent cycle reversibility. The scanning electron microscopy and transmission electron microscopy images reveal that NVPF-PCNB-20 particles were finer and covered by a uniform coating. The results show that the ionic liquid-acrylic acid copolymer not only make the material dispersion more uniform but also enhance the electronic conductivity and sodium storage performance of Na₃V₂(PO₄)₃F₃ effectively. This study may provide an effective way to synthesize nitrogen and boron codoped carbon-coated Na₃V₂(PO₄)₂F₃ with excellent electrochemical performance.

Recent Advances of Polymeric Membranes in Tackling Plasticization and Aging for Practical Industrial CO2/CH4 Applications—A Review

Membranes are a promising technology for bulk CO₂ separation from natural gas mixtures due to their numerous advantages. Despite the numerous fundamental studies on creating better quality membrane efficiency, scaling up the research work for field testing requires huge efforts. The challenge is to ensure the stability of the membrane throughout the operation while maintaining its high performance. This review addresses the key challenges in the application of polymeric technology for CO₂ separation, focusing on plasticization and aging. A brief introduction to the properties and limitations of the current commercial polymeric membrane is first deliberated. The effect of each plasticizer component in natural gas towards membrane performance and the relationship between operating conditions and the membrane efficiency are discussed in this review. The recent technological advancements and techniques to overcome the plasticization and aging issues covering polymer modification, high free-volume polymers, polymer blending and facilitated transport membranes (FTMs) have been highlighted. We also give our perspectives on a few main features of research related to polymeric membranes and the way forwards. Upcoming research must emphasize mixed gas with CO₂ including minor condensable contaminants as per real natural gas, to determine the competitive sorption effect on CO₂ permeability and membrane selectivity. The effects of pore blocking, plasticization and aging should be given particular attention to cater for large-scale applications.