Synthesis and characterization of potentially polymerizable amine-derived ionic liquids bearing 4-vinylbenzyl group

Design and Characterization of Epoxy Resin Systems Based on Mixtures of Imidazolium-Based Ionic Liquids with Docusate and Dicyanamide Anions

This study focuses on the synthesis, characterization, and application of four ionic liquids (ILs), three of which are being reported for the first time, with unique thermal properties and diverse anion-cation combinations, specifically in the context of epoxy resin polymerization. 1-3-Didodecylimidazolium dicyanamide (dDDIM DCA), 1-3-Didodecylimidazolium docusate (dDDIM DOSS), 1-ethyl-3-methylimidazolium dicyanamide (EMIM DCA), and 1-ethyl-3-methylimidazolium docusate (EMIM DOSS) were used to prepare six different mixtures with the same cation and with varying concentrations of DCA components, which is the main factor of an efficient polymerization, while the other component is intended to modify the properties of the cured resin. Mixtures based on EMIM cation demonstrated increased enthalpy and lower onset polymerization temperatures, indicating more efficient curing processes. The hardness of cured epoxy resins can be adjusted by altering the curing temperature and IL composition, with EMIM DCA and EMIM DOSS mixtures displaying high Shore A hardness, suitable for durable surface applications. In contrast, mixtures with higher dDDIM DCA proportions offered a balance between rigidity and flexibility, ideal for applications requiring both mechanical strength and elasticity.

Supported Ionic Liquid-Phase Materials (SILP) as a Multifunctional Group of Highly Stable Modifiers and Hardeners for Carbon and Flax Epoxy Composites

This paper introduces a novel approach to enhance epoxy resin formulations by using SILP materials as multifunctional hardeners and fillers in composite structures reinforced with carbon and flax fibers. This study explores the integration of ionic liquids (ILs) onto a silica support structure, presenting various permutations involving silica selection, ionic liquid choice, and concentration. The focus of this study was to elucidate the influence of SILP on resin curing ability and the mechanical properties of the resulting composites. Detailed research was conducted, including Brunauer-Emmett-Teller analysis (BET) for SILP materials and curing characterization for epoxy resin formulations with different SILP materials. Furthermore, the mechanical properties of the obtained composites were determined by Scanning Electron Microscopy analysis (SEM) (the force at break, the maximum elongation at break, tensile strength, and modulus of elasticity). Through SILP incorporation, the mechanical properties of composites, including the modulus of elasticity and tensile strength, are substantially improved, a phenomenon akin to traditional filler effects. The findings highlight SILP materials as prospective candidates for concurrent hardening and filling roles within composites (through a single-step procedure, with prolonged storage stability and controlled processing conditions), particularly pertinent as the composite industry veers toward epoxy bioresins necessitating liquefaction via temperature application.

Synthesis and Behavior of Hexamethylenetetramine-Based Ionic Liquids as an Active Ingredient in Latent Curing Formulations with Ethylene Glycol for DGEBA

The paper presents the preparation of new ionic liquids based on hexamethylenetetramine with bis(trifluoromethanesulfonyl)imide and dicyanamide anion, which were characterized in detail in terms of their purity (Ion Chromatography) and thermal properties (Differential Scanning Calorimetry), as well as stability. The obtained substances were used to develop curing systems with ethylene glycol, which were successfully tested for their application with bisphenol A diglycidyl ether molecule. In addition, the curing process and its relationship to the structure of the ionic liquid are characterized in detail. The research showed that hexamethylenetetramine-based new ionic liquids can be successfully designed using well-known and simple synthetic methods-the Delepine reaction. Moreover, attention was paid to their stability, related limitations, and the application of hexamethylenetetramine-based ionic liquids in epoxy-curing systems.

Thermal and Electrochemical Properties of Ionic Liquids Bearing Allyl Group with Sulfonate-Based Anions-Application Potential in Epoxy Resin Curing Process

Sulfonate-based ionic liquids (ILs) with allyl-containing cations have been previously obtained by us, however, the present study aims to investigate the thermal, electrochemical and curing properties of these ILs. To determine the temperature range in which ionic liquid maintains a liquid state, thermal properties must be examined using Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). Melting, cold crystallization and glass transition temperatures are discussed, as well as decomposition temperatures for imidazolium- and pyridinium-based ionic liquids. The conductivity and electrochemical stability ranges were studied in order to investigate their potential applicability as electrolytes. Finally, the potential of triflate-based ILs as polymerization initiators for epoxy resins was proven.

Optical Fiber Grating-Prism Fabrication by Imprint Patterning of Ionic-Liquid-Based Resist

We present a method of microstructure fabrication on the tip of the optical fiber using a UV soft-imprint process of polymerizable ionic liquid-based optical resist. Ionic liquid with two UV-sensitive vinylbenzyl groups in the structure was diluted in non-hazardous propylene glycol (PG) to obtain liquid material for imprinting. No additional organic solvent was required. The impact of propylene glycol amount and exposure dose on optical and mechanical properties was investigated. The final procedure of the UV imprint on the optical fiber tip was developed, including the mold preparation, setup building, UV exposure and post-laser cure. As the IL-containing vinylbenzyl groups can also be polymerized by the radical rearrangement of double bonds through thermal heating, the influence of the addition of 1-2% BHT polymerization inhibitor was verified. As a result, we present the fabricated diffraction gratings and the optical fiber spectrometer component-grism (grating-prism), which allows obtaining a dispersion spectrum at the output of an optical in line with the optical fiber long axis, as the main component in an optical fiber spectrometer. The process is very simple due to the fact that its optimization already starts in the process of molecule design, which is part of the trend of sustainable technologies. The final material can be designed by the tailoring of the anion and/or cation molecule, which in turn can lead to a more efficient fabrication procedure and additional functionalities of the final structure.

Synthesis, characterization and biological activity of bifunctional ionic liquids based on dodine ion

BACKGROUND

Development of new plant protection strategies has become an urgent matter in modern agriculture, in view of the evidently proved negative effect of currently used active ingredients of pesticides. In recent years, much effort has been made to eliminate the use of pesticides established to be toxic to pollinators.

RESULTS

In this study, we present a group of new bifunctional ionic liquids based on dodine (N-dodecylguanidine) cation whose physical and biological properties have been modified relative to those of the commercially available N-dodecylguanidine acetate. The decreased level of residue of active substances in plant tissues reduces their availability to pollinators, which increases the safety of their use. Moreover, lower environmental impact in combination with high antifungal activity and an additional biological function, that is the systemic acquired resistance induction, are in line with the goals of sustainable agriculture.

CONCLUSION

The presented approach shows the possibility of derivatization of commonly used fungicide into the form of bifunctional salts whose physical and biological properties can be easily modified. The paper reports successful design and synthesis of new sustainable and green chemicals for the modern agriculture, being less toxic to the environment and human health but still effective against pathogens. © 2021 Society of Chemical Industry.

The AEROPILs Generation: Novel Poly(Ionic Liquid)-Based Aerogels for CO2 Capture

CO₂ levels in the atmosphere are increasing exponentially. The current climate change effects motivate an urgent need for new and sustainable materials to capture CO₂. Porous materials are particularly interesting for processes that take place near atmospheric pressure. However, materials design should not only consider the morphology, but also the chemical identity of the CO₂ sorbent to enhance the affinity towards CO₂. Poly(ionic liquid)s (PILs) can enhance CO₂ sorption capacity, but tailoring the porosity is still a challenge. Aerogel’s properties grant production strategies that ensure a porosity control. In this work, we joined both worlds, PILs and aerogels, to produce a sustainable CO₂ sorbent. PIL-chitosan aerogels (AEROPILs) in the form of beads were successfully obtained with high porosity (94.6–97.0%) and surface areas (270–744 m²/g). AEROPILs were applied for the first time as CO₂ sorbents. The combination of PILs with chitosan aerogels generally increased the CO₂ sorption capability of these materials, being the maximum CO₂ capture capacity obtained (0.70 mmol g⁻¹, at 25 °C and 1 bar) for the CHT:P[DADMA]Cl_30%AEROPIL.

Molecularly imprinted films and quaternary ammonium-functionalized microparticles working in tandem against pathogenic bacteria in wastewaters

Despite major efforts to combat pollution, the presence of pathogenic bacteria is still detected in surface water, soil and even crops due to poor purification of domestic and industrial wastewaters. Therefore, we have designed molecularly imprinted polymer films and quaternary ammonium-functionalized- kaolin microparticles to target specifically Gram-negative bacteria (GNB) and Gram-positive bacteria (GPB) in wastewaters and ensure a higher purification rate by working in tandem. According to the bacteriological indicators, a reduction by 90 % was registered for GNB (total coliforms and Escherichia coli O157) and by 77 % for GPB (Clostridium perfringens) in wastewaters. The reduction rates were confirmed when using pathogen genetic markers to quantify particular types of GNB and GPB, like Salmonella typhimurium (reduction up to 100 %),Campylobacter jejuni (reduction up to 70 %), Enterococcus faecalis (reduction up to 81 %), Clostridium perfringens (reduction up to 97 %) and Shiga toxin-producing Escherichia coli (reduction up to 64 %). In order to understand the bactericidal activity of prepared films and microparticles, we have performed several key analyses such as Cryo-TEM, to highlight the auto-assembly mechanism of components during the films formation, and ²⁹ Si/¹³ C CP/MAS NMR, to reveal the way quaternary ammonium groups are grafted on the surface of kaolin microparticles.

Synthesis and characterization of nitrogen-based ionic liquids bearing allyl groups and examples of their application

The synthesis and characterization of a series of allyl-functionalized ionic liquids and examples of their application in catalysts and surface-functionalizing compound formation.