Polyionic liquid membrane: Recent development and perspective

High-flux ultrasonic processing for lithium separation using ionic liquid impregnated composite membranes

Battery industry, one of the most crucial components of the modern world, relies heavily on lithium production, and brines from the spent battery materials is one of the most important sources to exploit lithium. A new ultrasonic assisted membrane processing is proposed for lithium separation simulated brine. The effects of membrane composition, feed concentration, and ultrasonic conditions on the lithium extraction efficiency have been explored. The composite membrane including polysulfone (PSF) as the support and 1-alkyl-3-methylimidazolium hexafluorophosphate and tributyl phosphate as ionic liquid membrane. A porous PVC membrane has been used for prevention of the ILM loss. The optimal ultrasonic frequency is approximately 250 kHz, which matches the bulk modulus of the membrane and enhances the separation efficiency. Higher frequencies and optimized amplitude and pulse cycle settings further improve the lithium flux and selectivity. Moreover, higher flux and selectivity are achieved when separating lithium from alkali metal chlorides at higher feed concentrations, ranging from 250 ppm to 1000 ppm. The mechanism of enhanced lithium extraction by ultrasonics is attributed to the combination of microbubble formation, cavitation, and heat generation, which disrupt the concentration gradient and facilitate lithium transport across the membrane.

Organic iontronic memristors for artificial synapses and bionic neuromorphic computing

To tackle the current crisis of Moore's law, a sophisticated strategy entails the development of multistable memristors, bionic artificial synapses, logic circuits and brain-inspired neuromorphic computing. In comparison with conventional electronic systems, iontronic memristors offer greater potential for the manifestation of artificial intelligence and brain-machine interaction. Organic iontronic memristive materials (OIMs), which possess an organic backbone and exhibit stoichiometric ionic states, have emerged as pivotal contenders for the realization of high-performance bionic iontronic memristors. In this review, a comprehensive analysis of the progress and prospects of OIMs is presented, encompassing their inherent advantages, diverse types, synthesis methodologies, and wide-ranging applications in memristive devices. Predictably, the field of OIMs, as a rapidly developing research subject, presents an exciting opportunity for the development of highly efficient neuro-iontronic systems in areas such as in-sensor computing devices, artificial synapses, and human perception.

Ionenes as Potential Phase Change Materials with Self-Healing Behavior

Ionenes are poly(ionic liquids) (PILs) comprising a polymer backbone with ionic groups along the structure. Ionenes as solid-solid phase change materials are a recent research field, and some studies have demonstrated their potential in thermal dissipation into electronic devices. Eight ionenes obtained through Menshutkin reactions were synthesized and characterized. The analysis of the thermal tests allowed understanding of how the thermal properties of the polymers depend on the aliphatic nature of the dihalogenated monomer and the carbon chain length. The TGA studies concluded that the ionenes were thermally stable with T10% above 420 °C. The DSC tests showed that the prepared ionenes presented solid-solid transitions, and no melting temperature was appreciated, which rules out the possibility of solid-liquid transitions. All ionenes were soluble in common polar aprotic solvents. The hydrophilicity of the synthesized ionenes was studied by the contact angle method, and their total surface energy was calculated. Self-healing behavior was preliminarily explored using a selected sample. Our studies show that the prepared ionenes exhibit properties that make them potential candidates for applications as solid-solid phase change materials.

The Influence of Polycation and Counter-Anion Nature on the Properties of Poly(ionic liquid)-Based Membranes for CO2 Separation

The current investigation is focused on the development of composite membranes based on polymeric ionic liquids (PILs) containing imidazolium and pyridinium polycations with various counterions, including hexafluorophosphate, tetrafluoroborate, and bis(trifluoromethylsulfonyl)imide. A combination of spectroscopic methods was used to identify the synthesized PILs and characterize their interaction with carbon dioxide. The density and surface free energy of polymers were performed by wettability measurements, and the results are in good agreement with the permeability and selectivity obtained within the gas transport tests. It was shown that the membranes with a selective layer based on PILs exhibit relatively high permeability with CO₂ and high ideal selectivity CO₂/CH₄ and CO₂/N₂. Additionally, it was found that the type of an anion significantly affects the performance of the obtained membranes, with the most pronounced effect from bis-triflimide-based polymers, showing the highest permeability coefficient. These results provide valuable insights into the design and optimization of PIL-based membranes for natural and flue gas treatment.