Data for Time−Temperature Superposition of the Dissolution of Wool Keratin in the Ionic Liquid 1 Ethyl-3-methylimidazolium Acetate

The dissolution of wool yarns in the ionic liquid 1-ethyl-3-methyl-imidazolium acetate [C2mim][OAc] has been investigated. Wool yarns were submerged into [C2mim][OAc] and dissolved for various times and temperatures before coagulating with water. Optical microscopy was used to track the yarn’s cross-sectional area. We propose that there are two competing dissolution processes, one rate-limited by disulfide bonds at low temperatures (LTs), and a second by hydrogen bonds at high temperatures (HTs), with a crossover point between the two regimes at 70 ℃. The corresponding activation energies were ELT = 127 ± 9 kJ/mol and EHT = 34 ± 1 kJ/mol. The remaining area of the dissolved wool yarn could be shifted via time–temperature superposition to plot a single master curve of area against time for both regions. Finally, the dissolution could be modelled by a diffusion process, giving self-diffusion coefficients for the [C2mim][OAc] ions (0.64–15.31 × 10−13 m2/s).

本研究系统探究了羊毛纱线在离子液体（ionic liquid）乙酸1-乙基-3-甲基咪唑鎓（[C2mim][OAc]）中的溶解行为。将羊毛纱线浸没于[C2mim][OAc]中，在不同时长与温度条件下完成溶解后，通过水进行凝固再生；借助光学显微镜（optical microscopy）实时追踪纱线的横截面积变化。本研究提出存在两种相互竞争的溶解机制：低温（low temperatures, LTs）条件下，溶解速率由二硫键（disulfide bonds）限速；高温（high temperatures, HTs）条件下则由氢键（hydrogen bonds）限速，两种机制的转变临界点为70℃。对应两种机制的活化能分别为$E_{LT}=127pm9$ kJ/mol与$E_{HT}=34pm1$ kJ/mol。通过时温叠加（time-temperature superposition）原理，可将不同实验条件下溶解羊毛纱线的剩余横截面积数据进行归一化整合，最终得到覆盖两种溶解机制区域的统一横截面积-时间主曲线（master curve）。最后，本研究采用扩散过程对溶解行为进行建模，据此计算得到了[C2mim][OAc]离子的自扩散系数（self-diffusion coefficients），其取值范围为0.64~15.31×10⁻¹³ m²/s。