固-液-液润湿及用表面自由能模型预测其行为。
Solid-liquid-liquid wettability and its prediction with surface free energy models.
机构信息
Dept. Chemical Engineering and Applied Chemistry, University of Toronto, Canada.
Dept. Chemical Engineering and Applied Chemistry, University of Toronto, Canada.
出版信息
Adv Colloid Interface Sci. 2019 Feb;264:28-46. doi: 10.1016/j.cis.2018.10.003. Epub 2018 Oct 25.
Understanding wettability in solid-liquid-liquid (SLL or immersed) systems is important for numerous applications. However, predicting SLL wetting behavior on smooth surfaces has received little attention. The objective of this work was to explore alternatives to predict SLL wettability. To this end, we first present a review of solid surface free energy (σ) data obtained from solid-liquid-air (SLA) contact angle (θ) data and a summary of available SLL contact angle data for selected materials. Next, the existing surface free energy models for SLA systems are discussed in terms of their applicability to predict wettability of SLL systems. Finally, the SLL wettability of toluene drops on glass, mica, stainless steel and PTFE immersed in equilibrated Toluene-water-isopropyl alcohol (IPA) solutions was determined via contact angle (θ) measurements through the oil phase using the inverted sessile drop method over a wide range of interfacial tensions (γ). The results were plotted as γ·cosθ vs. γ, showing a smooth wetting transition from water-wetting to oil-wetting with decreasing γ for glass and stainless steel. Mica remained water-wetting, while PTFE oil-wetting. The Geometric (GM) and Harmonic (HM) mean approaches, and the Equation-of-State (EQS), originally developed for SLA systems, were extended to SLL systems. The extended GM and HM approaches could fit the SLL behavior after fitting the dispersive and polar contributions of the solid surface free energy (σ, σ), which required additional SLA θ measurements using PTFE as the reference surface. However, attempts at predicting θ for systems with high γ resulted in significant deviations, a problem linked to the high σ values required to fit the wettability of low γ systems (toluene-water-IPA). The extended EQS (e-EQS) method produced reasonable predictions of γ·cosθ for all the available experimental and literature data. The e-EQS method required fitting one of the interfacial energy terms (γ). For low surface energy materials, such as PTFE, the γ value should be fitted. For high surface energy materials, the γ should be fitted instead. The fitted values of γ for PTFE and γ for glass were consistent with the values obtained from Young's equation applied to SLA data.
理解固-液-液（SLL 或浸没）系统的润湿性对于许多应用都很重要。然而，对于光滑表面上 SLL 润湿性的预测却很少受到关注。本工作旨在探索替代方法来预测 SLL 的润湿性。为此，我们首先回顾了从固-液-气（SLA）接触角（θ）数据获得的固体表面自由能（σ）数据，并总结了选定材料的 SLL 接触角数据。接下来，根据其对 SLA 系统的适用性，讨论了现有的表面自由能模型，以预测 SLL 系统的润湿性。最后，通过反相悬滴法通过油相测量玻璃、云母、不锈钢和 PTFE 在平衡的甲苯-水-异丙醇（IPA）溶液中的甲苯液滴的接触角（θ），在很宽的界面张力（γ）范围内确定 SLL 的润湿性。结果表示为γ·cosθ与γ的关系图，对于玻璃和不锈钢，随着γ的降低，从亲水到亲油的润湿性转变很平滑。云母仍然是亲水的，而 PTFE 是亲油的。最初为 SLA 系统开发的几何（GM）和调和（HM）平均方法以及状态方程（EQS）被扩展到 SLL 系统。通过使用 PTFE 作为参考表面，对 GM 和 HM 扩展方法进行了拟合，可以拟合 SLL 行为，该拟合需要对固体表面自由能（σ，σ）的色散和极性贡献进行额外的 SLA θ 测量。然而，尝试预测具有高γ的系统的θ会导致显著的偏差，该问题与拟合低γ系统（甲苯-水-IPA）的润湿性所需的高σ值有关。扩展的 EQS（e-EQS）方法可以对所有可用的实验和文献数据进行合理的γ·cosθ预测。e-EQS 方法需要拟合界面能的一个项（γ）。对于低表面能材料，如 PTFE，应拟合γ值。对于高表面能材料，应拟合γ值。对于 PTFE 的拟合γ值和玻璃的拟合γ值与从 Young 方程应用于 SLA 数据中获得的值一致。
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