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arXiv 1801.02552cond-mat.softphysics.flu-dyn
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约束条件下晶体溶解和生长的薄膜模型

Thin film modeling of crystal dissolution and growth in confinement

Luca Gagliardi, Olivier Pierre-Louis

摘要:

我们提出了一个连续介质模型,描述了对基板限制的晶体接触的溶解和生长。分离晶体和衬底的液膜中的扩散和流体动力学在润滑近似下建模。该模型还考虑了分离压力和表面张力。在此框架内,我们得到的演化方程,该方程控制的非平衡动力学的晶体界面。基于这个模型,我们探讨了在外部负载下的溶解问题,称为压力解决方案。我们发现,在稳定状态下,发散(幂律)晶体表面排斥导致平坦的接触,作为负载的函数的溶解速率的单调增加。在足够大的载荷下,粘性耗散引起的力超过分离压力引起的力。相比之下,有限排斥(指数)导致尖锐的尖接触,溶解速率独立于负载和液体粘度。最后,在稳定状态下,晶体在被压向衬底时从不接触衬底,这与由于粘度和表面张力的组合效应而引起的晶体-表面相互作用的性质无关。

英文摘要:

We present a continuum model describing dissolution and growth of a crystal contact confined against a substrate. Diffusion and hydrodynamics in the liquid film separating the crystal and the substrate are modeled within the lubrication approximation. The model also accounts for the disjoining pressure and surface tension. Within this framework, we obtain evolution equations which govern the non-equilibrium dynamics of the crystal interface. Based on this model, we explore the problem of dissolution under an external load, known as pressure solution. We find that in steady-state, diverging (power-law) crystal-surface repulsions lead to flat contacts with a monotonic increase of the dissolution rate as a function of the load. Forces induced by viscous dissipation then surpass those due to disjoining pressure at large enough loads. In contrast, finite repulsions (exponential) lead to sharp pointy contacts with a dissolution rate independent on the load and on the liquid viscosity. Ultimately, in steady-state the crystal never touches the substrate when pressed against it, independently from the nature of the crystal-surface interaction due to the combined effects of viscosity and surface tension.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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