标题： 带电聚合物中离子隔离的最陡熵上升量子热力学框架预测 显示英文标题

标题： Predicting Ion Sequestration in Charged Polymers with the Steepest-Entropy-Ascent Quantum Thermodynamic Framework

摘要： 基于最陡熵上升的量子热力学框架被用于研究多链聚乙烯亚胺-亚甲基膦酸在从水溶液中捕获稀土离子（Eu$^{+3}$）的效果。该框架对离散能量本征结构应用热力学运动方程，以模拟铕离子与聚合物链反应位点的结合动力学。能量本征结构是通过非马尔可夫蒙特卡罗模型生成的，该模型估计了能级简并度。运动方程用于确定每个能级的占据概率，描述了聚合物系统从溶液中捕获稀土离子的热力学状态空间中的独特路径。进行第二次蒙特卡罗模拟，以将状态空间中的动力学路径与与聚合物相关的物理描述符联系起来，包括回转半径、曲折度和Eu邻近分布函数。这些描述符用于可视化聚合物在捕获过程中的演变。捕获的Eu$^{+3}$离子的比例取决于系统的总能量，较低的能量导致更高的捕获率。整体捕获的动力学依赖于运动方程所使用的最陡熵上升原理，该原理从初始非平衡状态生成独特的动力学路径。 显示英文摘要

摘要： The steepest-entropy-ascent quantum thermodynamic framework is used to investigate the effectiveness of multi-chain polyethyleneimine-methylenephosphonic acid in sequestering rare-earth ions (Eu$^{+3}$) from aqueous solutions. The framework applies a thermodynamic equation of motion to a discrete energy eigenstructure to model the binding kinetics of europium ions to reactive sites of the polymer chains. The energy eigenstructure is generated using a non-Markovian Monte Carlo model that estimates energy level degeneracies. The equation of motion is used to determine the occupation probability of each energy level, describing the unique path through thermodynamic state space by which the polymer system sequesters rare-earth ions from solution. A second Monte Carlo simulation is conducted to relate the kinetic path in state space to physical descriptors associated with the polymer, including the radius of gyration, tortuosity, and Eu-neighbor distribution functions. These descriptors are used to visualize the evolution of the polymer during the sequestration process. The fraction of sequestered Eu$^{+3}$ ions depends upon the total energy of the system, with lower energy resulting in higher sequestration. The kinetics of the overall sequestration are dependent on the steepest-entropy-ascent principle used by the equation of motion to generate a unique kinetic path from an initial non-equilibrium state.