Symmetry and Topology of Twin Boundaries and Five-Fold Twin Boundaries in Soft Crystals.
Symmetry and Topology of Twin Boundaries and Five-Fold Twin Boundaries in Soft Crystals.
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DOI：
10.1021/acs.langmuir.1c01262
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发表时间：
2021-08
期刊：
影响因子：
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通讯作者：
Hong-Kai Liu;Yong-Li Ma;Li-jun Ren;C. Kübel;Wen Wang
中科院分区：
文献类型：
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作者：
Hong-Kai Liu;Yong-Li Ma;Li-jun Ren;C. Kübel;Wen Wang
利用有机连接剂将不同的纳米团簇系在一起构建的异质团簇类似于脂质，并自组装成立方体，即由具有明确对称性和拓扑结构的独特纳米通道晶格组成的软晶体微粒。利用透射电子显微镜可以准确表征其内部多孔晶体结构。本文描述了具有双金刚石pn3_m结构的长方体中的双边界和五重双边界。我们的分析表明，骨骼单元的构象有明显的区别：正常骨骼单元为中心对称的交错构象，点群D3d；孪生边界上骨骼单元为镜像对称的重叠构象，点群D3h。这种对称的区别使通道在通过孪晶边界时改变方向并略微拉长，但拓扑结构保持不变。对于包含五倍双边界的长方体，其中一个通道位于粒子中心，无缝连接五个块。我们的结论是，两个不同的渠道系统仍然是连续的。这种基本的理解将有助于开发具有明确形状和特殊内部纳米结构的软晶体，用于高级应用。
Heteroclusters constructed by tethering dissimilar nanoclusters using organic linkers resemble lipids and self-assemble into cubosomes, namely, microparticles of soft crystals composed of unique nanochannel lattices with a defined symmetry and topology. The internal porous crystal structures can be accurately characterized using transmission electron microscopy. We herein describe twin boundaries and five-fold twin boundaries in cubosomes with a double-diamond Pn3̅m structure. Our analysis indicates a clear distinction in the conformation of the skeletal unit: a centrosymmetric staggered conformation with point group D3d for the normal skeletal unit and a mirror-symmetric eclipsed one with point group D3h for the skeletal unit on the twin boundary. This symmetry distinction causes the channels to change direction and elongate slightly as they pass through the twin boundary, but the topology is maintained. For cubosomes containing five-fold twin boundaries, one of the channels is in the center of the particles seamlessly connecting the five blocks. Our conclusion is that the two distinct channel systems are still continuous. This fundamental understanding will contribute to the development of soft crystals with defined shapes and special inner nanostructures for advanced applications.