Two families of a new generation of ionic liquids, in which the chiral cations are directly derived from naturally occurring α-amino acids and α-amino acid ester salts, have been obtained via very simple preparations.

A family of novel ionic liquids with amino acids and their derivatives as cations and environmentally benign materials as anions have been synthesized using easy preparation techniques. The ionic liquids obtained have the same characteristics as conventional imidazolium ionic liquids and the same chiralities as natural amino acids. Thermal stabilities, phase behaviour, viscosities and miscibilities of the representative family members have been investigated, generally showing no difference from conventional ionic liquids. These amino acid ionic liquids may be used as catalysts and “fully green” solvents in the cycloaddition of cyclopentadiene to methyl acrylate, which is a typical Diels–Alder reaction. This approach to treating amino acids and their derivatives can serve as an alternative to traditional ionic liquids having synthetic chemical components.

Particulate matter (PM) pollutants, including nanoscale particles (NPs), have been considered serious threats to public health. In this work, a self-powered air filter that can be used in high-efficiency removal of PM, including NPs, is presented. An ionic liquid–polymer (ILP) composite is irregularly distributed onto a sponge network to form an ILP@MF filter. Enabled by its unique electrochemical properties, the ILP@MF filter can remove PM_2.5 and PM₁₀ with high efficiencies of 99.59% and 99.75%, respectively, after applying a low voltage. More importantly, the charged ILP@MF filter realizes a superior removal for NPs with an efficiency of 93.77%. A micro-button lithium cell or silicon-based solar panel is employed as a power supply platform to fabricate a portable and self-powered face mask, which exhibits excellent efficacy in particulate removal compared to commercial masks. This work shows a great promise for high-performance purification devices and facile mask production to remove particulate pollutants.

The instructive structure-property relationships of ionic liquids (ILs) can be put to task-specific design of new functionalized ILs. The dicyanamide (DCA) ILs are typical CHN type ILs which are halogen free, chemical stable, low-viscous, and fuel-rich. The transport properties of DCA ionic liquids are significant for their applications as solvents, electrolytes, and hypergolic propellants. This work systematically investigates several important transport properties of four DCA ILs ([C₄mim][N(CN)₂], [C₄m₂im][N(CN)₂], N₄₄₄₂[N(CN)₂], and N₈₄₄₄[N(CN)₂]) including viscosity, conductivity, and electrochemical property at different temperatures. The melting points, temperature-dependent viscosities and conductivities reveal the structure-activity relationship of four DCA ILs. From the Walden plots, the imidazolium cations exhibit stronger cation–anion attraction than the ammonium cations. DCA ILs have relatively high values of electrochemical windows (EWs), which indicates that the DCA ILs are potential candidates for electrolytes in electrochemical applications. The cyclic voltammograms of Eu(III) in these DCA ILs at GC working electrode at various temperatures 303–333 K consists of quasi-reversible waves. The electrochemical properties of the DCA ILs are also dominated by the cationic structures. The current intensity (i_p), the diffusion coefficients (D_o), the charge transfer rate constants (k_s) of Eu(III) in DCA ILs all increased with the molar conductivities increased. The cationic structure-transport property relationships of DCA ILs were constructed for designing novel functionalized ILs to fulfill specific demands.