Ohadi Donya, Corti David S, Uline Mark J
Department of Chemical Engineering, University of South Carolina, Columbia, SC 29208, USA.
Janssen Research and Development, Welsh and McKean Roads, Spring House, PA 19477, USA.
Entropy (Basel). 2021 Jun 30;23(7):846. doi: 10.3390/e23070846.
Modifications to the traditional Onsager theory for modeling isotropic-nematic phase transitions in hard prolate spheroidal systems are presented. Pure component systems are used to identify the need to update the Lee-Parsons resummation term. The Lee-Parsons resummation term uses the Carnahan-Starling equation of state to approximate higher-order virial coefficients beyond the second virial coefficient employed in Onsager's original theoretical approach. As more exact ways of calculating the excluded volume of two hard prolate spheroids of a given orientation are used, the division of the excluded volume by eight, which is an empirical correction used in the original Lee-Parsons resummation term, must be replaced by six to yield a better match between the theoretical and simulation results. These modifications are also extended to binary mixtures of hard prolate spheroids using the Boublík-Mansoori-Carnahan-Starling-Leland (BMCSL) equation of state.
本文提出了对传统昂萨格理论的修正,用于对硬长椭球体系中的各向同性 - 向列相转变进行建模。使用纯组分体系来确定更新李 - 帕森斯重求和项的必要性。李 - 帕森斯重求和项使用卡纳汉 - 斯塔林状态方程来近似昂萨格原始理论方法中所采用的第二维里系数之外的高阶维里系数。随着采用更精确的方法来计算给定取向的两个硬长椭球的排斥体积,原始李 - 帕森斯重求和项中使用的将排斥体积除以八的经验修正必须替换为除以六,以便在理论结果和模拟结果之间获得更好的匹配。这些修正也通过使用布布利克 - 曼苏里 - 卡纳汉 - 斯塔林 - 利兰(BMCSL)状态方程扩展到硬长椭球的二元混合物。