Phase-field modeling of the dynamics of multicomponent vesicles: Spinodal decomposition, coarsening, budding, and fission.
Phase-field modeling of the dynamics of multicomponent vesicles: Spinodal decomposition, coarsening, budding, and fission.
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DOI：
10.1103/physreve.79.031926
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发表时间：
2009-03
期刊：
影响因子：
--
通讯作者：
Voigt A
中科院分区：
文献类型：
--
作者：
Lowengrub JS;Rätz A;Voigt A
我们发展了一个热力学上一致的相场模型来模拟多组分囊泡的动力学。该模型考虑了弯曲刚度、自发曲率、过剩(表面)能量和共存表面相之间的线张力。我们的方法类似于王和杜最近使用的方法。比奥尔。56,347(2008)]有一个关键的区别。在这里，我们集中于动力学演化，并显式求解表面质量守恒方程；王和杜没有考虑这个方程。利用自适应有限元数值方法对所得到的四阶强耦合非局部非线性方程组进行了数值求解。虽然该系统适用于三维空间，但我们在这里的研究仅限于囊泡为曲线的二维空间。数值计算发现，表面相的自发曲率和弯曲刚度之间的差异甚至在二维内也会导致芽的形成、不对称的囊泡形状和囊泡的分裂。此外，远离平衡构型的模拟表明，通过调幅节点分解和粗化进行的相分离不仅影响囊泡的形状，而且影响相分离动力学，特别是粗化，并可能导致较低的能态，而不是演化初始相分离的构型。
We develop a thermodynamically consistent phase-field model to simulate the dynamics of multicomponent vesicles. The model accounts for bending stiffness, spontaneous curvature, excess (surface) energy, and a line tension between the coexisting surface phases. Our approach is similar to that recently used by Wang and Du [J. Math. Biol. 56, 347 (2008)] with a key difference. Here, we concentrate on the dynamic evolution and solve the surface mass conservation equation explicitly; this equation was not considered by Wang and Du. The resulting fourth-order strongly coupled system of nonlinear nonlocal equations are solved numerically using an adaptive finite element numerical method. Although the system is valid for three dimensions, we limit our studies here to two dimensions where the vesicle is a curve. Differences between the spontaneous curvatures and the bending rigidities of the surface phases are found numerically to lead to the formation of buds, asymmetric vesicle shapes and vesicle fission even in two dimensions. In addition, simulations of configurations far from equilibrium indicate that phase separation via spinodal decomposition and coarsening not only affect the vesicle shape but also that the vesicle shape affects the phase separation dynamics, especially the coarsening and may lead to lower energy states than might be achieved by evolving initially phase-separated configurations.