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arXiv 1908.08890cond-mat.softcond-mat.mtrl-sci
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混合物在第二次淬灭后的相分离:组成不均匀性

Phase separation of mixtures after a second quench: composition heterogeneities

Pablo de Castro, Peter Sollich

摘要:

我们调查二元混合物进行相分离后,第二次(更深)的温度淬火成两相和三相共存区域。分析是基于以前开发的气液分离在通用混合物的晶格理论。我们以前的结果,考虑了任意数量的物种和一个单一的淬火,表明,由于缓慢的变化组成,致密的胶体混合物可以分两个阶段相分离。此外,较致密的相包含长寿命的组成不均匀性,起源于收缩域的界面。在这里,我们预测几个新的影响,出现后的第二次淬火,主要与拥挤的程度可以减缓“分馏”,即平衡的组合物。它们包括长寿的定期安排的二级域;润湿的分级界面相反的分级层;“表面”定向的spinodal“波”传播的初级界面;一个“死区”,没有相分离发生;和,在三相共存的情况下,丝状形态所产生的二级域。

英文摘要:

We investigate binary mixtures undergoing phase separation after a second (deeper) temperature quench into two- and three-phase coexistence regions. The analysis is based on a lattice theory previously developed for gas-liquid separation in generic mixtures. Our previous results, which considered an arbitrary number of species and a single quench, showed that, due to slow changes in composition, dense colloidal mixtures can phase-separate in two stages. Moreover, the denser phase contains long-lived composition heterogeneities that originate as the interfaces of shrunk domains. Here we predict several new effects that arise after a second quench, mostly associated with the extent to which crowding can slow down 'fractionation', i.e. equilibration of compositions. They include long-lived regular arrangements of secondary domains; wetting of fractionated interfaces by oppositely fractionated layers; 'surface'-directed spinodal 'waves' propagating from primary interfaces; a 'dead zone' where no phase separation occurs; and, in the case of three-phase coexistence, filamentous morphologies arising out of secondary domains.

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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