Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia.
Wigner Research Centre for Physics, H-1121 Budapest, Konkoly Thege út 29-33., Hungary.
J Colloid Interface Sci. 2020 Feb 15;560:730-742. doi: 10.1016/j.jcis.2019.10.094. Epub 2019 Oct 25.
The structural details, viscosity trends and dynamic phenomena in t-butanol/water solutions are closely related on the molecular scales across the entire composition range. Utilizing the experimental small- and wide-angle x-ray scattering (SWAXS) method, molecular dynamics (MD) simulations and the 'complemented-system approach' method developed in our group it is possible to comprehensively describe the structure-viscosity-dynamics relationship in such structurally versatile hydrogen-bonded molecular liquids, as well as in similar, self-assembling systems with pronounced molecular and supramolecular structures at the intra-, inter-, and supra-molecular scales.
The SWAXS and x-ray diffraction experiments and MD simulations were performed for aqueous t-butanol solutions at 25 °C. Literature viscosity and self-diffusion data were also used.
The interpretive power of the proposed scheme was demonstrated by the extensive and diverse results obtained for aqueous t-butanol solutions across the whole concentration range. Four composition ranges with qualitatively different structures and viscosity trends were revealed. The experimental and calculated zero-shear viscosities and molecular self-diffusion coefficients were successfully related to the corresponding structural details. The hydrogen bonds that were, along with hydrophobic effects, recognized as the most important driving force for the formation of t-butanol aggregates, show intriguing lifetime trends and thermodynamic properties of their formation.
在整个组成范围内，叔丁醇/水溶液的结构细节、粘度趋势和动力学现象在分子尺度上密切相关。利用我们小组开发的实验小角和广角 X 射线散射 (SWAXS) 方法、分子动力学 (MD) 模拟和“互补体系方法”，可以全面描述这种结构多样的氢键分子液体以及类似的自组装系统中的结构-粘度-动力学关系，这些系统在分子和超分子尺度上具有明显的分子和超分子结构。
在 25°C 下对水合叔丁醇溶液进行了 SWAXS 和 X 射线衍射实验以及 MD 模拟。还使用了文献中的粘度和自扩散数据。
通过在整个浓度范围内获得的广泛而多样的水合叔丁醇溶液结果，证明了所提出方案的解释能力。揭示了四个具有定性不同结构和粘度趋势的组成范围。实验和计算的零剪切粘度和分子自扩散系数成功地与相应的结构细节相关联。氢键被认为是形成叔丁醇聚集体的最重要驱动力之一，与疏水效应一起，氢键表现出有趣的寿命趋势和形成的热力学性质。
