Division of Molecular and Materials Simulation, State Key Lab of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China.
J Chem Phys. 2012 Mar 28;136(12):124904. doi: 10.1063/1.3697484.
By modeling the ring-like molecule as a pearl necklace of freely jointed hard sphere, we develop a new equation of state (EOS) for the ring-like fluids on the basis of generalized Flory-Huggins (GFH) theory. Before proposing the new EOS of the ring-like fluids, we first modify the generalized Flory-Huggins theory for the chain fluids by incorporating a function related to the packing fraction into the insertion probability. The results indicate that the modified GFH EOS can predict the compressibility factors more accurately than the GFH EOS, especially for the intermediate and high packing fractions (η ≥ 0.157). Subsequently, the modified GFH theory-based EOS for the ring-like fluids is proposed. Compared to the Monte Carlo data of 3-mer, 4-mer, 5-mer, 6-mer, 16-mer, and 32-mer ring-like fluids, our EOS exhibits the best prediction among four EOSs for the compressibility factors at intermediate and high packing fractions (η ≥ 0.157), although our EOS also shows a slight underestimation for the compressibility factors at low packing fractions. In summary, this is the first report on the generalized Flory-Huggins theory-based EOS for the ring-like fluids. It is expected that the same strategy can be applied to these fluids with more complex architectures.
通过将环状分子建模为自由连接的硬球体的珍珠项链，我们在广义 Flory-Huggins（GFH）理论的基础上为环状流体开发了一种新的状态方程（EOS）。在提出环状流体的新 EOS 之前，我们首先通过将与堆积分数相关的函数纳入插入概率来修改用于链状流体的广义 Flory-Huggins 理论。结果表明，与 GFH EOS 相比，经过修正的 GFH EOS 可以更准确地预测压缩因子，尤其是在中间和高堆积分数（η≥0.157）时。随后，提出了基于修正的广义 Flory-Huggins 理论的环状流体 EOS。与 3-mer、4-mer、5-mer、6-mer、16-mer 和 32-mer 环状流体的 Monte Carlo 数据相比，我们的 EOS 在中间和高堆积分数（η≥0.157）下对压缩因子的预测表现最好，尽管我们的 EOS 对低堆积分数下的压缩因子也略有低估。总之，这是首次报道基于广义 Flory-Huggins 理论的环状流体 EOS。预计相同的策略可以应用于具有更复杂结构的这些流体。
