Entropic pressure on fluctuating solid membranes
Entropic pressure on fluctuating solid membranes
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DOI：
10.1016/j.jmps.2023.105523
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发表时间：
2023-12
影响因子：
5.3
通讯作者：
Rubayet Hassan;Maria Alejandra Garzon;Wei Gao;Fatemeh Ahmadpoor
中科院分区：
文献类型：
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作者：
Rubayet Hassan;Maria Alejandra Garzon;Wei Gao;Fatemeh Ahmadpoor
生物和结晶膜由于其低弯曲刚度而在室温下表现出明显的波动。这些波动对它们的整体机械行为和与外部物体的相互作用有重大影响。当两个膜接近时，它们相互抑制彼此的波动，导致排斥力在这些膜的机械行为中起着关键作用。从力学的角度来看，结晶膜被建模为具有固有剪切阻力的固体膜，而生物膜通常被描述为没有剪切阻力的流体实体。在此前提下，提出了两个波动的生物膜之间的熵力的标度为p ≠ 1/d3，其中d为膜间距离。然而，有许多情况下，这些膜显示剪切阻力和行为类似于固体膜。在本文中，我们建立了一个非线性弹性统计力学模型来研究作用在受限的、波动的固体膜上的熵力。我们证明，由于固体膜的非线性弹性，熵力的尺度不同相比，流体膜。我们的预测与分子动力学模拟得到的结果吻合得很好，涉及石墨烯，一种固体膜的代表，被限制在两个刚性壁之间。
Biological and crystalline membranes exhibit noticeable fluctuations at room temperature due to their low bending stiffness. These fluctuations have a significant impact on their overall mechanical behavior and interactions with external objects. When two membranes come into proximity, they mutually suppress each other’s fluctuations, leading to a repulsive force that plays a pivotal role in the mechanical behavior of these membranes. From the mechanics point of view, crystalline membranes are modeled as solid membranes with inherent shear resistance, whereas biological membranes are commonly described as fluidic entities without shear resistance. Under this premise, the entropic force between two fluctuating biological membranes is proposed to scale as p∝ 1/d 3, where d is the intermembrane distance. Yet, there are numerous instances where these membranes display shear resistance and behave akin to solid membranes. In this paper, we develop a statistical mechanics model within nonlinear elasticity to study the entropic force acting on a confined, fluctuating solid membrane. We demonstrate that, due to the nonlinear elasticity of solid membranes, the entropic force scales differently compared to that of fluid membranes. Our predictions align well with the results obtained from molecular dynamics simulations involving graphene, a representative of a solid membrane, confined between two rigid walls.