Bartke Jörg, Hentschke Reinhard
Fachbereich Mathematik und Naturwissenschaften, Bergische Universität, D-42097 Wuppertal, Germany.
Phys Rev E Stat Nonlin Soft Matter Phys. 2007 Jun;75(6 Pt 1):061503. doi: 10.1103/PhysRevE.75.061503. Epub 2007 Jun 21.
The gas-isotropic liquid-nematic liquid phase behavior of the Stockmayer fluid is studied using molecular dynamics simulation together with a mean field lattice model. We obtain coexistence curves of the Stockmayer fluid over a wide range of dipole strengths, temperatures, and densities, including the transition from the isotropic liquid to the ferroelectric liquid. In our simulations we do not observe the disappearance of the isotropic gas-isotropic liquid coexistence at high dipole strength contrary to earlier findings based on Monte Carlo techniques. Even though the formation of reversible dipole chains strongly affects the location of the critical point, it does not lead to its disappearance. These results are supported by a mean field lattice model which yields good qualitative, and in parts quantitative, agreement with our simulations. In addition, we also investigate the gas-isotropic liquid phase behavior for different polarizabilities.
采用分子动力学模拟和平均场晶格模型研究了斯托克迈耶流体的气体-各向同性液体-向列相液晶相行为。我们得到了斯托克迈耶流体在很宽的偶极强度、温度和密度范围内的共存曲线，包括从各向同性液体到铁电液体的转变。在我们的模拟中，与早期基于蒙特卡罗技术的研究结果相反，我们没有观察到在高偶极强度下各向同性气体-各向同性液体共存的消失。尽管可逆偶极链的形成强烈影响临界点的位置，但它不会导致临界点消失。平均场晶格模型支持了这些结果，该模型在定性和部分定量方面与我们的模拟结果吻合良好。此外，我们还研究了不同极化率下的气体-各向同性液体相行为。
