A multifunctional and sustainable poly(ionic liquid)-quaternized chitosan hydrogel with thermal-triggered reversible adhesion.

A quaternized chitosan (QCS)@poly(ionic liquid) (PIL) hydrogel adhesive was prepared by in-situ ultraviolet (UV)-induced copolymerization of 1-vinyl-3-butyl imidazolium bromide ([BVIm][Br]) and methacryloyloxyethyl trimethylammonium chloride (DMC) in QCS aqueous solution without using any crosslinkers, which was stably crosslinked by reversible hydrogen bonding together with ion association and exhibited excellent adhesion, plasticity, conductivity and recyclability properties. Moreover, its thermal/pH-responsive behaviors and intermolecular interaction mechanism of thermal-triggered reversible adhesion were discovered, meanwhile good biocompatibility, antibacterial properties, repeated stickiness and degradability were also proved. The results showed that the newly developed hydrogel could make various tissues, organic, inorganic or metal materials adhered tightly within 1 min; after 10 binding-peeling cycles, the adhesive strength to glass, plastic, aluminum and porcine skin still remained beyond 96 %, 98 %, 92 % and 71 % of the original, respectively. The adhesion mechanism involves ion dipole interaction, electrostatic interaction, hydrophobic interaction, coordination, cation-π interaction, H-bonding and van der Waals force. For above merits, the new tricomponent hydrogel is expected to be applied in biomedical field to achieve adjustable adhesion and on-demand peeling.

How to apply terpenoid-based deep eutectic solvents for removal of antibiotics and dyes from water: Theoretical prediction, experimental validation and quantum chemical evaluation.

This study proposed a theoretical prediction method and mechanism investigation for the extraction of antibiotics and dyes from aqueous media using terpenoid-based deep eutectic solvents (DESs). Firstly, Conductor-like Screening Model for Real Solvents (COSMO-RS) approach was applied to predict selectivity, capacity and performance index in the extraction of 15 target compounds including antibiotics (tetracyclines, sulfonamides, quinolones, ß-lactams) and dyes by 26 terpenoid-based DESs, and thymol-benzyl alcohol shows promising theoretical selectivity and extraction efficiency for the target compounds. Moreover, the structures of both hydrogen bond acceptors (HBA) and hydrogen bond donors (HBD) have an impact on the predicted extraction performance, which can be improved by tailoring those candidates with higher polarity, smaller molecular volume, shorter alkyl chain length and the presence of aromatic ring structures, etc. According to the predicted molecular interactions revealed by σ-profile and σ-potential, the DESs with HBD ability can promote the separation process. Furthermore, reliability of proposed prediction method was confirmed by experimental verification, indicating that the trends of theoretical extraction performance index were similar with the experimental results by using actual samples. At last, the extraction mechanism was evaluated by quantum chemical calculations based on visual presentations, thermodynamic calculations and topological properties; and the target compounds showed favorable energies of solvation to transfer from aqueous phase to DESs phase. The proposed method has been proved with potential to provide the efficient strategies and guidance for more applications (e.g., microextraction, solid phase extraction, adsorption) with similar molecular interactions of green solvents in environmental research.

Triphase dynamic extraction system involved with ionic liquid and deep eutectic solvent for various bioactive constituents from Tartary buckwheat simultaneously.

Friendly and highly efficient acquisition of multiple active components from foods is always of great interest. For synchronous extraction and separation flavonoids together with oil from Tartary buckwheat, a new triphase dynamic system was developed with magnetic nanofluid based on deep eutectic solvent (N888-Cl/lauric acid, 1:2) (liquid phase 1), ionic liquid ([C4mim]Br) aqueous solution (liquid phase 2) and raw material powders (solid phase). It was the first time that two types of green solvents were simultaneously applied and assisted by magnetic separation. Through the investigation on key properties and operational conditions of this system, the extraction efficiency of oil and flavonoids in liquid phase 1 and 2 was achieved as 35.29 and 41.17 mg/g respectively, which were higher than that of conventional ways. Then kinetic and thermodynamics mechanisms were discovered comprehensively. After targeted recovery, the spectral characterization and antioxidant activity of two products proved the effectiveness of the developed method.

Chiral ionic liquid-multi walled carbon nanotubes composite membrane applied to the separation of amino acid enantiomers.

Various membranes are playing more and more important roles in the field of analytical and preparative applications of general interest, and some of them have been used in enantioresolution for amino acids (AAs) or similar bioactive molecules. In this study, a new composite membrane was prepared with chiral ionic liquid (CIL) of [BuPyro] [L-Pro] as chiral selector together with multi walled carbon nanotubes (MWCNTs) and additives through a simple way for the first time. Based on such a separation medium, the enantioresolution of amino acid enantiomers were achieved by forming ternary ligand complexes with Cu(II). It was comprehensively characterized by various ways, and key preparation conditions were discovered. After comparing the performance of three operation modes on the resolution of racemic phenylalanine, the effects of main influential factors were investigated and enantiomeric excess value (e.e.%) was 90.2% for the (D,L)-Phe aqueous solution (membrane thickness: 0.15±0.02 mm, total weight: 80 mg, CIL: 41.7%). Through effective desorption, up to 98.1% of the target was recovered. Finally, the mechanism of resolution was revealed by molecular simulation, kinetics and isotherm models, and the difference of interactive energy between ternary complexes of L-Phe-Cu(II)-CIL and D-Phe-Cu(II)-CIL was calculated as 1.56 kcal/mol. The membrane also remained stable after the post-treatment and showed good potential in chiral separation.

A new deep eutectic solvent-agarose gel with hydroxylated fullerene as electrical "switch" system for drug release.

A novel portable conductive system of hydroxylated fullerene (TEGs-C60) embedded on the deep eutectic solvent (DES, choline chloride/malic acid)-agarose gel was developed for on-demand curation with skin contact. It has been found with better elasticity, conductivity and thermal stability than agarose hydrogel. Especially, the electro-responsive drug releasing amount on the skin of mice and live rabbits through small batteries was proved to be 4-5 times of those without electrical stimulation, which reached the level of clinic daily dosage. Meanwhile, it also showed good biocompatibility and much higher antibacterial rate against S. aureus (78.67 ± 0.80 %) together with E. coli (92.08 ± 1.50 %) than those of commercial chitosan gel. The new electrical "switch" gel system provided an effective and useful development strategy for advanced drug delivery.

Rethinking the Applications of Ionic Liquids and Deep Eutectic Solvents in Innovative Nano-Sorbents.

With the development of green chemistry and nano materials, new alternatives to traditional volatile solvents are one of many important hotspots in the field of nano materials. Ionic liquids (ILs) and deep eutectic solvents (DESs) as excellent alternative solvents are being applied in the innovation of nano-sorbents, including nanoparticles, nanogels, and nanofluid. ILs and DESs are often used as carriers/modifiers/dispersers of nano-sorbents to enhance the adsorption capacity and selectivity in the extraction procedure. Various extraction technologies, such as solid-phase extraction, solid-phase microextraction, micro-solid phase extraction, hollow fiber liquid phase microextraction, and magnetic solid-phase extraction, have also been promoted by them to achieve rapid development. This paper focused on the latest development of nano-sorbents based on ILs and DESs. The problems and bottlenecks encountered were analyzed in order to provide meaningful and valuable references for the related research and thus promote further development and application of alternative solvents-assisted nano-sorbents.