Giant vesicles at the prolate-oblate transition: A macroscopic bistable system
Giant vesicles at the prolate-oblate transition: A macroscopic bistable system
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DOI：
10.1209/epl/i1996-00230-6
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发表时间：
1996-11-10
期刊：
影响因子：
--
通讯作者：
Seifert, U
中科院分区：
文献类型：
--
作者：
Dobereiner, HG;Seifert, U
研究表明，巨大的磷脂囊泡在几秒的时间尺度内表现出长长形和扁圆形之间的热激活转变。从这种囊泡的波动轮廓中，我们提取椭圆度作为有效反应坐标，其时间概率分布是双峰的。然后，我们重建有效势，从中得出 k(B)T 量级的活化能，与理论计算一致。这种转变的动力学在双稳态电位的过阻尼扩散的克莱默模型中得到了很好的描述。因此，该系统可以作为宏观双稳态的模型。
Giant phospholipid vesicles are shown to exhibit thermally activated transitions between a prolate and an oblate shape on a time scale of several seconds. From the fluctuating contour of such a vesicle we extract ellipticity as an effective reaction coordinate whose temporal probability distribution is bimodal. We then reconstruct the effective potential from which we derive an activation energy of the order of k(B)T in agreement with theoretical calculations. The dynamics of this transition is well described within a Kramers model of overdamped diffusion in a bistable potential. Thus, this system can serve as a model for macroscopic bistability.