Joanna Feder-Kubis

Recently developed ionic liquids (ILs) are gaining attention for their antibacterial properties in the face of increasing resistance to conventional antibiotics. Their structural tunability enables the design of compounds that balance antimicrobial potency and acceptable toxicity. We investigated two monoterpene-based functionalized ionic liquids (FILs)─[(1R,2S,5R)-(−)-mentoxymethyl]dimethyltetradecylammonium chloride and [(1R,2S,5R)-(−)-mentoxymethyl]tetradecylimidazolium chloride─which differ in cationic core (ammonium vs imidazolium) but share an identical hydrophobic alkyl chain. Using a multiscale approach combining Langmuir monolayers, Brewster angle microscopy, atomic force microscopy, and molecular dynamics (MD) simulations, we examined their interactions with model bacterial membrane interfaces. Both FILs integrated readily into lipid monolayers, disrupted lipid packing, and altered interfacial organization, with pronounced effects in systems enriched in anionic lipids such as cardiolipin and POPG. Despite structural differences, the two FILs showed comparable antibacterial activity, notable given the typically higher toxicity of ammonium-based FILs. MD simulations revealed that electrostatic interactions dominate FIL–lipid association, with cationic headgroups binding preferentially to phosphate oxygens, while hydrogen bonding contributes minimally. The cations preferentially bind to phosphate oxygens of anionic lipids, explaining the enhanced activity against both Gram-positive and Gram-negative membrane models. The combined experimental–computational approach highlights key design principles for developing next-generation ILs with targeted activity at biological surfaces.

The environmental behavior and phytotoxicity of functionalized ionic liquids (FILs) featuring imidazolium cations bearing a cyclic (-)-menthol or a linear 1-decanol-derived substituent and fluorinated anions were evaluated in a soil bioassay (Raphanus sativus). Structure-activity relationships were determined by integrating measurements (water solubility, surface tension, molecular volume) with in-silico descriptors (n-octanol-water partition coefficient, log K_OW; bioconcentration factor, log BCF; asymmetry). Lipophilicity and bioaccumulation correlated with fresh-mass inhibition (EC₅₀). More-fluorinated, larger, and charge-delocalized anions were more hydrophobic, elevating bioaccumulation and toxicity. Within menthol-based series, sulfonylimide-based FILs were more phytotoxic (EC₅₀ 74.7, 107.3 mg·kg^-1 soil dry weight) than sulfonate analogues (e.g., 299.1 mg·kg^-1). FILs with linear cations were more phytotoxic and showed higher log K_OW/BCF than cyclic analogues, consistent with greater molecular volume, higher asymmetry, and reduced hydration. Antioxidant responses paralleled EC₅₀, implicating oxidative stress. This workflow improves risk assessment and provides green-by-design criteria to prioritise safer ILs.

The growing demand for advanced nanomaterials (NMs) has led to the development of safer, cost-effective, and bio-compliant synthesis methods for the nanoparticles (NPs) in compliance with stringent quality and environmental standards, particularly in the field of healthcare section. Conventional NPs preparation methods often fall short in terms of safety and environmental concerns, hindering their compatibility with modern biomedicine and biotechnology. In this context, ionic liquids (ILs) can play a pivotal role in the fabrication of NPs with precise morphologies and bioapplicability. The incorporation of ILs offers more efficient and environmentally friendly routes for the synthesis of NPs with deliberate control over their fundamental properties (e.g., in terms of surface morphology, functionalities, dispersibility, and size distribution). The use of ILs in bioactive NPs is often in line with the principles of green chemistry to help establish a fundamental strategy for biological applications. Here, a comprehensive review is offered to describe the perspectives of ILs-NPs (bio)systems with special emphasis on biotechnology and biomedicine. The design of useful and applicable ILs-NPs (bio)systems is proposed under the umbrella concept of green principles. Furthermore, the six principles of green ILs-NPs biosystems are outlined to meet the requirements of green chemistry. Finally, our discussions are extended to cover research gaps and future directions of ILs-NPs within the framework of sustainable development. This review highlights the promising role of ILs in advancing green chemistry practices with regard to the synthesis and application of NPs for the betterment of biotechnology and biomedicine.

This study explores task-specific ionic liquids (TSILs) in smart floor systems, highlighting their strong electrical rectification abilities and previously established wood preservative properties. Two types of TSILs, featuring a “sweet” anion and a terpene-based cation, were used to treat selected wood samples, allowing for a comparison of their physical and electrical performance with untreated and commercially treated counterparts. Drop shape analysis and scanning electron microscopy were employed to evaluate the surface treatment before and after coating. Near-IR was used to confirm the presence of a surface modifier, and thermogravimetric analysis (TGA) was utilized to assess the thermal features of the treated samples. The different surface treatments resulted in varied triboelectric nanogenerator (TENG) parameters, with the molecular structure and size of the side chains being the key determining factors. The best results were achieved with TSILs, with the instantaneous voltage increasing by approximately five times and the highest voltage reaching 300 V under enhanced loading. This work provides fresh insights into the potential application spectrum of TSILs and opens up new avenues for directly utilizing tested ionic compounds in construction systems.

Mixtures of nematic liquid crystals (LCs) with chiral ionic liquids (CILs) may find application as active materials for electrically driven broadband mirrors. Five nematic liquid crystal hosts were mixed with twenty three ionic liquids, including chiral ones, and studied in terms of their miscibility within the nematic phase. Phase diagrams of the mixtures with CILs which exhibited twisted nematic phase were determined. Miscibility, at levels between 2 and 5 wt%, was found in six mixtures with cyanobiphenyl-based liquid crystal host—E7. On the other hand, the highest changes in the isotropization temperature was found in the mixtures with isothiocyanate-based liquid crystal host—1825. Occurrence of chemical reactions was found. A novel chiral binaphtyl-based organic salt [N₁₁₁₁₆][BNDP] was synthesized and, in reaction to the 1825 host, resulted in high helical twisting power product(s). Selectivity of the reaction with the isothiocyanate-based liquid crystal was found.

This study explores the transport properties of bis(trifluoromethylsulfonyl)imide-based ionic liquids with a naturally derived (1R,2S,5R)-(−)-menthol moiety in the cationic part. In particular, we investigated the dependence of the dynamic viscosity and electrical conductivity as functions of the alkyl chain length. An important finding of this study is that both properties show nonmonotonic behavior with respect to the alkyl chain length. The nonmonotonic dependency is an obstacle for establishing the relationships between the structure and transport properties of homologues. To overcome this difficulty, we recommend fast property screening using a theoretical model that we developed, which allows for efficient viscosity prediction by means of the group contribution method. As demonstrated in this study, the model allows for reliable predictions of viscosity in the studied series with an overall relative deviation of less than 8%.

Infections with Candida spp. are commonly found in long-time denture wearers, and when under immunosuppression can lead to stomatitis. Imidazolium ionic liquids with an alkyl or alkyloxymethyl chain and a natural (1R,2S,5R)-(−)-menthol substituent possess high antifungal and antiadhesive properties towards C. albicans, C. parapsilosis, C. glabrata and C. krusei. We tested three compounds and found they disturbed fungal plasma membranes, with no significant hemolytic properties. In the smallest hemolytic concentrations, all compounds inhibited C. albicans biofilm formation on acrylic, and partially on porcelain and alloy dentures. Biofilm eradication may result from hyphae inhibition (for alkyl derivatives) or cell wall lysis and reduction of adhesins level (for alkyloxymethyl derivative). Thus, we propose the compounds presented herein as potential anti-fungal denture cleaners or denture fixatives, especially due to their low toxicity towards mammalian erythrocytes after short-term exposure.