SHAPES OF FLEXIBLE VESICLES AT CONSTANT VOLUME
SHAPES OF FLEXIBLE VESICLES AT CONSTANT VOLUME
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DOI：
10.1063/1.464689
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发表时间：
1993-05-01
影响因子：
4.4
通讯作者：
BAUMGARTNER, A
中科院分区：
文献类型：
--
作者：
BAUMGARTNER, A
本文用Monte Carlo方法和有限尺度法分析了具有固定表面积N和恒定体积V的立方晶格上的三维囊泡模型。在囊泡可接近的体积的整个范围内，均方回转半径服从约N（nu）f（VN-3 nu/2）的标度律[R2]，其中nu几乎等于4/5。标度函数f（x）在起皱点x（c）处具有几乎等于0.177的最小值，将分支构象V的区域分离为大约N（x < x（c））和扩展构象V的区域分离为大约N3/2（x > x（c））。在皱曲点V（c）几乎等于0.177N3nu/2处，构象发生皱曲，[R2]c几乎等于0.146N（nu）。囊泡的形状在膨胀状态下是球对称的，而在分支状态下是扁球形的。交叉的特征在于不对称参数A，其表现出几乎等于（15 x）-3.0的有效幂律[A]。引入了一个皱曲参数，表征在体积减小时囊泡的粗糙度增加。同时还讨论了平均局部曲率的标度。
A three-dimensional vesicle model on the cubic lattice with fixed surface area N and at constant volume V is analyzed using a Monte Carlo method and finite size scaling. On the entire range of volumes accessible to the vesicles, the mean square radius of gyration obeys a scaling law [R2] approximately N(nu)f(VN-3nu/2), where nu almost-equal-to 4/5. The scaling function f (x) has a minmum at the crumpling point x(c) almost-equal-to 0.177, separating the regimes of branched conformations V approximately N (x < x(c)) and expanded conformations V approximately N3/2 (x > x(c)). At the crumpling point V(c) almost-equal-to 0.177N3nu/2, the conformations are crumpled with [R2]c almost-equal-to 0.146N(nu). The shapes of vesicles are spherically symmetric in the inflated regime, whereas oblate in the branched regime. The crossover is characterized by the asymmetry parameter A, which exhibits an effective power law [A] almost-equal-to (15x)-3.0. A crumpling parameter is introduced characterizing the increasing roughness of the vesicles at decreasing volume. The scaling of the mean local curvature is discussed as well.