School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester, M13 9PL, UK.
Phys Chem Chem Phys. 2018 Jun 6;20(22):15118-15127. doi: 10.1039/c8cp02415d.
Colloids have a striking relevance in a wide spectrum of industrial formulations, spanning from personal care products to protective paints. Their behaviour can be easily influenced by extremely weak forces, which disturb their thermodynamic equilibrium and dramatically determine their performance. Motivated by the impact of colloidal dispersions in fundamental science and formulation engineering, we have designed an efficient Dynamic Monte Carlo (DMC) approach to mimic their out-of-equilibrium dynamics. Our recent theory, which provided a rigorous method to reproduce the Brownian motion of colloids by MC simulations, is here generalised to reproduce the Brownian motion of colloidal particles during transitory unsteady states, when their thermodynamic equilibrium is significantly modified. To this end, we investigate monodisperse and bidisperse rod-like particles in the isotropic phase and apply an external field that forces their reorientation along a common direction and induces an isotropic-to-nematic phase transition. We also study the behaviour of the system once the external field is removed. Our simulations are in excellent quantitative agreement with Brownian Dynamics simulations when the DMC results are rescaled with a time-dependent acceptance ratio, which depends on the strength of the applied field.
胶体在广泛的工业配方中具有显著的相关性，涵盖了从个人护理产品到防护涂料。它们的行为很容易受到极弱的力的影响，这些力会扰乱它们的热力学平衡，并极大地决定它们的性能。受胶体分散体在基础科学和配方工程中影响的启发，我们设计了一种有效的动态蒙特卡罗（DMC）方法来模拟它们的非平衡动力学。我们最近的理论提供了一种通过 MC 模拟再现胶体布朗运动的严格方法，在此基础上，我们将其推广到模拟胶体颗粒在过渡不稳定状态下的布朗运动，此时它们的热力学平衡会发生显著变化。为此，我们在各向同性相中研究了单分散和双分散棒状粒子，并施加一个外部场，迫使它们沿着一个共同的方向重新取向，并诱导各向同性到向列相的相变。我们还研究了一旦移除外部场后系统的行为。当 DMC 结果通过与施加场强度相关的时变接受率进行缩放时，我们的模拟与布朗动力学模拟在定量上非常吻合。
