DEFECTS IN FLEXIBLE MEMBRANES WITH CRYSTALLINE ORDER
DEFECTS IN FLEXIBLE MEMBRANES WITH CRYSTALLINE ORDER
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DOI：
10.1103/physreva.38.1005
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发表时间：
1988-07-15
影响因子：
2.9
通讯作者：
NELSON, DR
中科院分区：
文献类型：
--
作者：
SEUNG, HS;NELSON, DR
利用连续介质弹性理论和零温数值模拟方法研究了具有内晶序的柔性薄膜中的孤立位错和向错。这些缺陷与囊泡中的脂质双层或溶致近晶型液晶的L β相中的脂质双层有关。我们首先模拟平板膜中的缺陷，得到的数值结果与平面弹性理论吻合得很好。随着膜半径的增加，向错和位错最终表现出屈曲转变。我们推广了连续介质理论，使之包括了这种屈曲缺陷，并在非外延极限下求解了向错方程。临界半径时，屈曲开始筛选出内部弹性应力的数值确定。屈曲缺陷的计算机模拟证实了预测的向错能，并给出了一个有限的位错能量的证据。
We study isolated dislocations and disclinations in flexible membranes with internal crystalline order, using continuum elasticity theory and zero-temperature numerical simulation. These defects are relevant, for instance, to lipid bilayers in vesicles or in the L β phase of lyotropic smectic liquid crystals. We first simulate defects in flat membranes, obtaining numerical results in good agreement with plane elasticity theory. Disclinations and dislocations eventually exhibit a buckling transition with increasing membrane radius. We generalize the continuum theory to include such buckled defects, and solve the disclination equations in the inextensional limit. The critical radius at which buckling starts to screen out internal elastic stresses is determined numerically. Computer simulation of buckled defects confirms predictions of the disclination energies and gives evidence for a finite dislocation energy.