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arXiv 1807.09293physics.chem-ph
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二元溶液成核热力学和动力学

Thermodynamics and kinetics of nucleation in binary solutions

Nikolay V. Alekseechkin

摘要:

为研究凝聚态二元溶液成核动力学提供了一种经典热力学和宏观动力学相结合的新途径。该理论涵盖了沿着成核机制进行的液体和固体溶液的分离,以及液-固转化,例如,熔融合金的结晶。被认为是一元和二元沉淀的形核的情况下。导出了临界核的平衡方程,并将其应用于核生长的宏观方程中;利用这些方程计算了稳态成核率。本方法可以应用到一般情况下的非理想溶液,计算进行的模型内的经典成核理论(CNT)近似暗示的核和恒定的表面张力的体积特性的正规溶液。在有限厚度层方法的框架中示出了将理论扩展到CNT近似之外的方式。从与共存的体相,吸附和表面张力对温度,半径和组合物的依赖性方程的表面层的平衡方程导出。讨论了表面效应对成核热力学和动力学的影响。

英文摘要:

A new approach that is a combination of classical thermodynamics and macroscopic kinetics is offered for studying the nucleation kinetics in condensed binary solutions. The theory covers the separation of liquid and solid solutions proceeding along the nucleation mechanism, as well as liquid-solid transformations, e.g., the crystallization of molten alloys. The cases of nucleation of both unary and binary precipitates are considered. Equations of equilibrium for a critical nucleus are derived and then employed in the macroscopic equations of nucleus growth; the steady state nucleation rate is calculated with the use of these equations. The present approach can be applied to the general case of non-ideal solution; the calculations are performed on the model of regular solution within the classical nucleation theory (CNT) approximation implying the bulk properties of a nucleus and constant surface tension. The way of extending the theory beyond the CNT approximation is shown in the framework of the finite-thickness layer method. From equations of equilibrium of a surface layer with coexisting bulk phases, equations for adsorption and the dependences of surface tension on temperature, radius, and composition are derived. Surface effects on the thermodynamics and kinetics of nucleation are discussed.

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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