National Science Center, Kharkov Institute of Physics and Technology, Kharkov, Ukraine.
J Chem Phys. 2013 Apr 28;138(16):164504. doi: 10.1063/1.4802201.
Heterogeneous nucleation (condensation and boiling) on planar solid surfaces is described taking into account changes of the state parameters of the critical clusters in dependence on supersaturation. The account of the variation of the state parameters of the cluster phase on nucleation is performed in the framework of the generalized Gibbs' approach. One-component van der Waals fluids are chosen as a model for the analysis of the basic qualitative characteristics of the process. The analysis is performed for both hydrophobic and hydrophilic surfaces and similarities and differences between condensation and boiling processes are discussed for the two different cases. It is shown that, in the generalized Gibbs' approach, contact angle and catalytic factor for heterogeneous nucleation become dependent on the degree of metastability (undercooling or superheating) of the fluid. For the case of formation of a droplet in supersaturated vapor on a hydrophobic surface and bubble formation in a liquid on a hydrophilic surface the solid surface has only a minor influence on nucleation. In the alternative cases of condensation of a droplet on a hydrophilic surface and of bubble formation in a liquid on a hydrophobic surface, nucleation is significantly enhanced by the solid. Effectively, the existence of the solid surface results in a significant shift of the spinodal to lower supersaturations as compared with homogeneous nucleation. Qualitatively the same behavior is observed now near the new (solid surface induced) limits of instability of the fluid as compared with the behavior near to the spinodal curve in the case of homogeneous nucleation.
考虑到过饱和度对临界团簇状态参数的影响，描述了平面固体表面上的异质成核（凝结和沸腾）。在广义 Gibbs 方法的框架内，考虑了团簇相状态参数随成核的变化。选择单组分范德华流体作为分析过程基本定性特征的模型。对疏水性和亲水性表面进行了分析，并讨论了两种不同情况下的凝结和沸腾过程之间的相似性和差异。结果表明，在广义 Gibbs 方法中，异质成核的接触角和催化因子取决于流体的亚稳度（过冷或过热）程度。对于在疏水性表面上过饱和蒸汽中形成液滴和在亲水性表面上液体中形成气泡的情况，固体表面对成核的影响很小。在替代情况下，即亲水性表面上液滴的凝结和疏水性表面上液体中气泡的形成，固体显著增强了成核。实际上，与均匀成核相比，固体的存在导致旋节线向更低的过饱和度显著移动。与均匀成核情况下旋节线附近的行为相比，现在在接近流体的新（由固体表面引起的）不稳定性极限时，观察到了相同的定性行为。
