Dissolution and interaction of white hide powder in [Etmim][C₁₂H₂₅SO₄]

Ethyl chloroacetate, 1-methylimidazole and sodium dodecyl sulfate as raw materials, ester-functionalized surface active ionic liquid 3-methyl-(ethoxycarbonylmethyl)-imidazolium dodecylsulfate ([Etmim][C₁₂H₂₅SO₄]) was synthesized for white hide powder dissolution. The structure of [Etmim][C₁₂H₂₅SO₄] was ascertained by ¹H NMR. The solubility of white hide powder in [Etmim][C₁₂H₂₅SO₄] was measured from 60 °C to 140 °C with 20 °C interval. Compared to [Etmim]Cl, [Etmim][C₁₂H₂₅SO₄] was superior to dissolve white hide powder. The physicochemical performances of white hide powder/[Etmim][C₁₂H₂₅SO₄] was measured by tensiometry, electrical conductivity and fluorimetry. The tensiometry results showed that the cmc of [Etmim][C₁₂H₂₅SO₄] was 1.41 mmol/L at 298.15 K, indicating that [Etmim][C₁₂H₂₅SO₄] exhibited higher surface activity than traditional anionic surfactants. The regenerated white hide powder was characterized by FT-IR, TGA, DSC, and XRD. Thermodynamics profiles demonstrated that the secondary structure of white hide powder was slightly destroyed during dissolution. The interaction mechanism between white hide powder and [Etmim][C₁₂H₂₅SO₄] was studied by DFT computation using triple peptide Gly-Pro-Hyp (as GPHyp) as model. Seven hydrogen bonds were found between GPHyp and [Etmim][C₁₂H₂₅SO₄]. The simulation results suggested that the formation of hydrogen bonds accelerated the dissolution of white hide powder in [Etmim][C₁₂H₂₅SO₄].