This study investigated the dissolution of silk multifilament fibers in the ionic liquid 1-ethyl-3-methylimidazolium acetate. The dissolution process was found to create a silk composite fiber, comprising undissolved silk multifilaments surrounded by a coagulated silk matrix. The dissolution procedure was carried out for a range of temperatures and times. The resulting composite fibers were studied using a combination of optical microscopy, wide-angle X-ray diffraction (XRD), and tensile testing. An azimuthal (α) XRD scan enabled the orientation of the composite silk filaments to be quantified through a second Legendre polynomial function (P₂). The P₂ results could be shifted to construct a single master curve using time–temperature superposition (TTS). The shifting factors were found to have an Arrhenius behavior with an activation energy of 138 ± 13 kJ/mol. Using a simple rule of mixtures, the P₂ measurements were used to calculate the dissolved silk matrix volume fraction (V_m), which also displayed TTS forming a single master curve with an activation energy of 139 ± 15 kJ/mol. The tensile Young’s modulus of each silk composite filament was measured, and these results similarly formed a master curve with an activation energy of 116 ± 12 kJ/mol.

中文翻译：

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蚕丝纤维在离子液体1-乙基-3-甲基咪唑鎓乙酸盐中的溶解时间-温度叠加

这项研究研究了丝状复丝纤维在离子液体乙酸1-乙基-3-甲基咪唑鎓中的溶解情况。发现溶解过程产生了丝复合纤维，其包含被凝固的丝基质包围的未溶解的丝复丝。溶解程序在一定温度和时间范围内进行。结合光学显微镜，广角X射线衍射（XRD）和拉伸测试对所得复合纤维进行了研究。方位角（α）XRD扫描可通过第二勒让德多项式函数（P ₂）来量化复合丝的方向。在P ₂可以使用时间-温度叠加（TTS）将结果偏移以构建一条主曲线。发现位移因子具有阿累尼乌斯行为，其活化能为138±13 kJ / mol。使用简单的混合规则，使用P ₂测量来计算溶解的丝绸基质体积分数（V _m），这也显示出TTS形成了一条主曲线，活化能为139±15 kJ / mol。测量了每根丝复合纤维的拉伸杨氏模量，这些结果类似地形成了具有116±12 kJ / mol活化能的主曲线。