1 hexyl 3 methylimidazolium chloride

Poly (acrylonitrile-co-methyl acrylate) (PANMA) (acrylonitrile weight percentage: ~94%) and polyvinylpyrrolidone (PVP) (360,000 g/mol) were purchased from Sigma–Aldrich (St. Louis, MO, USA). PANMA acted as C- and N- source precursor, and PVP acted as a sacrificial material. Standard Reference Material^® 2682c subbituminous coal (referred as 2682 coal) from Wyodak–Anderson coal seam (powder river basin, PRB Coal), and Standard Reference Materials^® 2684c bituminous coal (referred as 2684 coal) from Pittsburgh coal seam were purchased from National Institution of Standards and Technology (NIST) (Gaithersburg, MD, USA). Figure 1 lists four ILs (>98.0% HPLC and <1.0% H₂O impurity) used in coal extraction: 1-butyl-2,3-dimethylimidazolium chloride (C₄m₂imCl), 1-ethyl-3-methylimidazolium chloride (C₂mimCl), 1-Hexyl-3-methylimidazolium chloride (C₆mimCl) and 1-Butyl-3-methylimidazolium chloride (C₄mimCl), which were purchased from Sigma–Aldrich (St. Louis, MO, USA) and used as extraction solvents without further purification. 1-Methyl-2-pyrrolidinone (NMP) (99.5%) (Sigma–Aldrich) was used as a solvent to obtain coal char from coal/ILs solution through a centrifuge. N,N-Dimethylformamide (DMF, 99.8%) (Sigma–Aldrich) was used as an organic solvent to dissolve PANMA, PVP and coal precursors for electrospinning process.

Ethanol, mEthanol, and calcium chloride (CaCl₂) were purchased from Kanto Chemical (Tokyo, Japan). Sodium carbonate (Na₂CO₃) and lithium chloride were purchased from FUJIFILM Wako Pure Chemical (Osaka, Japan). 1-Hexyl-3-methyl-imidazolium chloride ([HMIM][Cl], ≥95% purity) was purchased from Sigma-Aldrich (St. Louis, MO, USA) as the ionic liquid. 1,1,1,3,3,3-Hexafluoro-2-propanol (HFIP) was purchased from Fluorochem (Derbyshire, UK). All chemical reagents were used without further purification.
Silkworm silk cocoons were kindly donated by Tsuruoka Silk (Yamagata, Japan). Marseilles soap (additive free) was purchased from Miyoshi Soap (Tokyo, Japan). A cellulose dialysis tubing (diameter, 21.4 mm; molecular weight cutoff (MWCO), 12,000–14,000 Da) was purchased from SERVA Electrophoresis (Heidelberg, Germany). Nitrogen (N₂) gas was purchased from Taiyo Nippon Sanso (Tokyo, Japan). Water purification systems (PURELAB flex 3, ELGA LabWater, High Wycombe, UK) were used to obtain ultrapure water.

1-ethyl-3-methylimidazolium chloride (EMIM) (purity > 98%, dry) and 1-hexyl-3-methylimidazolium chloride (HMIM) (purity > 98.5%, dry) were purchased from Sigma-Aldrich (Darmstadt, Germany). They are water-soluble ILs, and were dissolved in ultrapure water at different molar concentrations for the swelling experiments.

The following standards were used: rutin hydrate, formononetin, daidzein, and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) from Sigma-Aldrich (Darmstadt, Germany). The reagents 1-methylimidazolium, 1-chlorobutane, and potassium hexafluorophosphate; IL 1-n-butyl-3-methylimidazolium tetrafluoroborate ([C₄mim][BF₄]) and 1-hexyl-3-methylimidazolium chloride ([C₆mim]Cl); choline chloride, glycerol, 1,4-butanediol, and levulinic acid from Sigma-Aldrich (Darmstadt, Germany). Reagents sodium nitrite (Vetec®) and aluminum chloride (Proquímicos®); Fluorescein sodium salt and α, α′-Azodiisobutyramidine dihydrochloride (AAPH) from Sigma-Aldrich (Darmstadt, Germany). Culture mediums: Mueller Hinton Agar (Himedia®) and Nutrient broth (Himedia®). Salmonella enteritidis ATCC 13076 and Staphylococcus aureus ATCC 19095 were supplied by the Bacterial Culture Collection of the Oswaldo Cruz Institute – FIOCRUZ (Manguinhos, Rio de Janeiro, Brazil). Vancomycin (30 μg/disc) and Meropenem (10 μg/disc; DME®) antibiotic filter paper discs and inert filter paper discs (DME®).