A model liquid crystalline system based on rodlike viruses with variable chirality and persistence length
A model liquid crystalline system based on rodlike viruses with variable chirality and persistence length
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DOI：
10.1039/b822478a
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发表时间：
2009-01-01
期刊：
影响因子：
3.4
通讯作者：
Dogic, Zvonimir
中科院分区：
文献类型：
--
作者：
Barry, Edward;Beller, Daniel;Dogic, Zvonimir
我们将突变丝状病毒 fd Y21M 的相行为与传统 fd 野生型 (wt) 的相行为进行了比较。尽管两种病毒之间唯一的微观差异在于主要外壳蛋白 pVIII 的单个氨基酸，但我们发现了显着不同的宏观相行为。与 fd wt 相比，fd Y21M 的各向同性-胆甾相转变位置移至较低密度。这是由于两种病毒的灵活性存在显着差异。 fd wt的持续长度为2.8+/-0.7μm，而fdY21M的持续长度为9.9+/-1.6μm。 fd Y21M 的大余辉长度使其成为基本上刚性的棒，从而首次能够对各向同性向列相变的 Onsager 理论进行定量测试。更引人注目的是两种病毒手性相行为的差异。两种病毒均形成胆甾相，其中fd wt形成左手胆甾相螺旋，而fd Y21M形成右手胆甾相螺旋。在给定密度下，两个系统之间的胆甾醇间距大小相差五倍。使用两种病毒的混合物，我们创建了一个对其宏观手性进行可调控制的液晶系统。
We compare the phase behavior of a mutant filamentous virus, fd Y21M, to that of a conventional fd wild-type (wt). We find significantly different macroscopic phase behavior despite the only microscopic difference between the two viruses being in a single amino acid of the major coat protein pVIII. Compared to fd wt, the location of the isotropic-cholesteric phase transition for fd Y21M shifts to lower densities. This is attributable to a significant difference in the flexibility of the two viruses. The persistence length of fd wt is 2.8 +/- 0.7 mu m, whereas the persistence length of fd Y21M is 9.9 +/- 1.6 mu m. The large persistence length of fd Y21M makes it an essentially rigid rod, thus allowing for the first time a quantitative test of the Onsager theory for the isotropic-nematic phase transition. Even more striking, is the difference in the chiral phase behavior of the two viruses. Both viruses form cholesteric phases, with the fd wt forming a left-handed cholesteric helix, and the fd Y21M forming a right-handed one. At a given density, the magnitude of the cholesteric pitch between the two systems is different by fivefold. Using mixtures of the two viruses, we create a liquid crystalline system with a tunable control over its macroscopic chirality.