2018-01-012024-05-18https://scholars.lib.ntu.edu.tw/handle/123456789/700862摘要：含氫鍵的締合性物質，例如水、醇類等，是工業中常使用的溶劑。透過氫鍵的作用，這類物質所構成的混合物往往具有非常特別的熱力學性質與相行為，例如同時具有高臨界溫度(UCST，低於此溫度發生液液相分離)與低臨界溫度(LCST，高於此溫度時發生液液相分離)，也因此締合性流體不論在基礎研究或是工業應用都具有重要且特別的意義。一般熱力學模型在描述締合性物質時，通常需要對其作用力進行有別於一般凡德瓦作用力的處理，方能夠準確地描述其相行為。然而，既使如此，我們發現，大部分模型對於締合性流體系值的預測，其準確度仍不及非締合性流體。同時，我們注意到，目前對於氫鍵作用力的處理方式，多是調整其作用力強度以勉強再現實驗數據，卻忽略氫鍵與凡德瓦作用力的重要本質性差異，即是氫鍵形成時施體與受體在空間上的方位限制。因此，在本計畫中，我們將把形成氫鍵的方向限制加入我們過去所開發的熱力學模型COSMO-SAC中，從我們初步成果推測，此方法將可大幅提升預測模型的準確度與可靠度。在三年的計劃中，我們將驗證此法對於各種不同的氫鍵系統(O…H, N…H, F…H)的表現，特別是在液液相平衡中的高低臨界溫度。此外，我們也將比較模型中使用的氫鍵作用強度，與第一性原理計算的結果，確認模型參數的可靠度。最後我們將嘗試推廣此方法至電解質溶液與離子溶液。我們預期這項工作將可大幅增加我們在預測締合性流體相行為的能力，能夠在分子與材料設計上，提供更可靠的物性資料。<br> Abstract: Chemicals capable of forming hydrogen bonds, such as water and alcohols, are common solvents used in the chemical industry. Mixtures containing such species often exhibit special properties and phase behaviors, such as having both upper and lower critical solution temperatures (UCST and LCST). Therefore, such associating fluids are of great importance in industrial application and in fundamental study for understanding hydrogen bonding. Conventional thermodynamic models adopt different interaction parameters for hydrogen bonds. However, it is often found that using a different interaction parameter (often temperature dependent) may not provide satisfactory predictions to the phase behavior of these systems. One possible reason for the limited success of conventional approach is its ignorance of the orientation constraints between the donor and acceptor of the hydrogen bond formers. In this project, we will introduce such constraints to the predictive COSMO-SAC activity coefficient model previously developed by us. Our preliminary results show that the additional orientation constraint indeed improves the prediction accuracy and reliability of associating fluids. In this 3 year project, we plan to systematically examine the performance of this approach to different types of hydrogen bonding systems, including O…H, N…H, F…H. We will focus on the quality in reproducing various phase behaviors, in particular the liquid-liquid equilibrium and the UCST and LCST. We will compare the strength of hydrogen bonds in the COSMO-SAC model to that from first principle calculations. This ensures the reliability of the interaction parameters. We will also generalize this approach for electrolyte solutions and ionic liquids. We expect this work to greatly enhance our capability in predicting the properties of associating fluids, which is important for molecular design of new materials.氫鍵強度氫鍵方向性締合性流體液液相平衡臨界溫度Strength of hydrogen bondorientation of hydrogen bondassociating fluidliquid-liquid equilibriumupper/lower critical solution temperature