Chiral Polymeric Nanocapsules and Their Use for Conformational Deracemization of Liquid Crystals
Chiral Polymeric Nanocapsules and Their Use for Conformational Deracemization of Liquid Crystals
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DOI：
10.1021/acs.jpcc.8b06005
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发表时间：
2018-08-09
影响因子：
3.7
通讯作者：
Abu-Reziq, Raed
中科院分区：
文献类型：
--
作者：
Zoabi, Amani;Santiago, Melvin G.;Abu-Reziq, Raed
本文首次报道了手性纳米胶囊的制备及其性质。将l -赖氨酸与聚亚甲基聚苯基异氰酸酯进行界面乳液聚合，得到聚脲衍生物手性壳。这些纳米胶囊的手性表现在其诱导液晶构象离消旋的能力上。这种诱导手性是通过“Raynes实验”来测量的，在该实验中，细胞的边界条件使液晶定向器从一个表面到另一个表面进行+/- 90度旋转。从各向同性到向列相的冷却过程中出现了左旋和右旋定向扭畴。由于液晶的弱诱导手性，一个方向的旋转在能量上更有利，其畴尺寸扩大，导致畴壁弯曲。曲率作为胶囊浓度的函数来测量，并作为周围液晶中手性诱导的度量。
We present the first preparation and properties of chiral nanocapsules. The chiral shell, a polyurea derivative, was obtained by interfacial emulsion polymerization of L-lysine with polymethylene polyphenyl isocyanate. The chirality of these nanocapsules was manifested by its ability to induce conformational deracemization of a liquid crystal. This induced chirality was measured using the "Raynes' experiment", in which the boundary conditions of cells impose a +/- 90 degrees rotation of the liquid crystal director from one surface to the other. Both left- and right-handed director twist domains appear on cooling from the isotropic to the nematic phase. Owing to the weak induced chirality of the liquid crystal, one sense of director rotation is energetically more favorable and its domain size expands, resulting in curvature of the domain walls. The curvature was measured as a function of capsule concentration and serves as a metric of the induction of chirality in the surrounding liquid crystal.