Surfaces Decorated with Enantiomorphically Pure Polymer Nanohelices via Hierarchical Chirality Transfer across Multiple Length Scales
Surfaces Decorated with Enantiomorphically Pure Polymer Nanohelices via Hierarchical Chirality Transfer across Multiple Length Scales
复制标题
通过跨多个长度尺度的分层手性传递用对映纯聚合物纳米螺旋装饰表面
DOI：
10.1002/adma.202108386
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发表时间：
2022
影响因子：
29.4
通讯作者：
Bräse, Stefan
中科院分区：
文献类型：
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作者：
Varadharajan, Divya;Nayani, Karthik;Zippel, Christoph;Spuling, Eduard;Cheng, Kenneth C.;Sarangarajan, Swetha;Roh, Sangchul;Kim, John;Trouillet, Vanessa;Bräse, Stefan
介观尺度的手性材料是通过光刻方法、手性构建块的组装以及在偏振光存在下的合成来制备的。通常，这些过程会产生微米级的结构，需要复杂的自上而下的操作，或者依赖于繁琐的不对称分离。化学气相沉积(CVD)将手性前驱体聚合到支撑的液晶膜(LCS)中，可以得到超层级排列的对映体纯纳米纤维。根据1-羟乙基[2.2]对环番前驱体的分子手性，由非手性向列相模板形成扩展的对映体纳米螺旋阵列。手性纳米螺旋的阵列延伸了数百微米，并一致地显示出对映体微图案。单个纳米螺旋的间距取决于手性前体的对映体过剩和纯度，这与双扭曲LC指向矢构型的理论模型是一致的。在化学气相沉积过程中，分子和介观尺度的不对称性结合在一起，形成规则扭曲的纳米螺旋。对映体表面允许广泛的功能性质的剪裁，例如弱手性体系的不对称诱导。
Mesoscale chiral materials are prepared by lithographic methods, assembly of chiral building blocks, and through syntheses in the presence of polarized light. Typically, these processes result in micrometer‐sized structures, require complex top–down manipulation, or rely on tedious asymmetric separation. Chemical vapor deposition (CVD) polymerization of chiral precursors into supported films of liquid crystals (LCs) are discovered to result in superhierarchical arrangements of enantiomorphically pure nanofibers. Depending on the molecular chirality of the 1‐hydroxyethyl [2.2]paracyclophane precursor, extended arrays of enantiomorphic nanohelices are formed from achiral nematic templates. Arrays of chiral nanohelices extend over hundreds of micrometers and consistently display enantiomorphic micropatterns. The pitch of individual nanohelices depends on the enantiomeric excess and the purity of the chiral precursor, consistent with the theoretical model of a doubly twisted LC director configuration. During CVD of chiral precursors into cholesteric LC films, aspects of molecular and mesoscale asymmetry combine constructively to form regularly twisted nanohelices. Enantiomorphic surfaces permit the tailoring of a wide range of functional properties, such as the asymmetric induction of weak chiral systems.