论文标题
具有两个构象的吸附分子的反向凝结
Inverse condensation of adsorbed molecules with two conformations
论文作者
论文摘要
常规的气体液相转变具有共存线，其单调和正斜率与我们的直觉一致，即冷却始终会导致凝结。在这里，我们研究了逆现象，加热后，吸附的有机分子将吸附的有机分子凝结成致密的结构域。我们的考虑是由最近的实验激励的[Aeschlimann等人，Angew。化学（2021）]，它证明了有序分子单层的部分溶解以及冷却时分子的动员。我们介绍了一个简单的晶格模型，在该模型中，每个位点可以具有与未占用和两个可分离的分子构象相对应的三个状态。我们通过蒙特卡洛模拟，平均场理论研究了该模型，并基于ISING模型在二维中的分析解决方案进行了精确的结果。我们的结果应广泛地适用于具有不同熵或热容量的不同构象的分子。
Conventional gas-liquid phase transitions feature a coexistence line that has a monotonic and positive slope in line with our intuition that cooling always leads to condensation. Here we study the inverse phenomenon, condensation of adsorbed organic molecules into dense domains upon heating. Our considerations are motivated by recent experiments [Aeschlimann et al., Angew. Chem. (2021)], which demonstrate the partial dissolution of an ordered molecular monolayer and the mobilization of molecules upon cooling. We introduce a simple lattice model in which each site can have three states corresponding to unoccupied and two discernible molecular conformations. We investigate this model through Monte Carlo simulations, mean-field theory, and exact results based on the analytical solution of the Ising model in two dimensions. Our results should be broadly applicable to molecules with distinct conformations that have sufficiently different entropies or heat capacities.
