Engineering Colossal Anisotropic Thermal Expansion into Organic Materials through Dimensionality Control
Engineering Colossal Anisotropic Thermal Expansion into Organic Materials through Dimensionality Control
复制标题
DOI：
10.1021/acs.chemmater.3c01677
复制
发表时间：
2023-08-23
影响因子：
8.6
通讯作者：
Hutchins，Kristin M.
中科院分区：
文献类型：
--
作者：
Juneja，Navkiran;Unruh，Daniel K.;Hutchins，Kristin M.
固态材料的热膨胀（TE）行为受分子结构和超分子结构的影响。对于通过共价键组装的固态材料，如碳同素异形体，具有高维数的固体（如金刚石）比具有低维数的固体（如富勒烯、石墨）表现出更少的TE。因此，随着固体尺寸的增加，TE减小。然而，通过非共价键组装的固态材料中与TE相关的尺寸的类似和系统变化尚未被研究。在这里，我们设计了一系列基于尺寸层次的固体，以提供具有零维（0D）， 1D和2D氢键结构的材料。二维材料是石墨和共价有机框架的结构类似物，我们证明了这些二维固体具有独特的双轴零TE，具有各向异性和沿π堆叠方向的巨大TE （α ~ 200 MK-1）。在二维氢键固体中的总体行为与二维共价键固体相似；然而，这些氢键固体沿π堆叠方向的TE系数比二维石墨或磷同素异形体高一个数量级。本文描述的分层材料设计策略和与TE性能的相关性可以广泛应用于设计和合成由共价键或非共价键维持并控制固态行为的新型固态材料。
Thermal expansion (TE) behavior in solid-state materials is influenced by both molecular and supramolecular structure. For solid-state materials assembled through covalent bonds, such as carbon allotropes, solids with higher dimensionality (i.e., diamond) exhibit less TE than solids with lower dimensionality (e.g., fullerene, graphite). Thus, as the dimensionality of the solid increases, the TE decreases. However, an analogous and systematic variation of the dimensionality in solid-state materials assembled through noncovalent bonds with a correlation to TE has not been studied. Here, we designed a series of solids based on dimensional hierarchy to afford materials with zero-dimensional (0D), 1D, and 2D hydrogen-bonded structures. The 2D materials are structural analogues of graphite and covalent-organic frameworks, and we demonstrate that these 2D solids exhibit unique biaxial zero TE with anisotropic and colossal TE along the π-stacked direction (α ∼ 200 MK–1). The overall behavior in the 2D hydrogen-bonded solids is similar to 2D covalent-bonded solids; however, the coefficient of TE along the π-stacked direction for these hydrogen-bonded solids is an order of magnitude higher than in 2D graphite or phosphorus allotropes. The hierarchal materials design strategy and correlation to TE properties described herein can be broadly applied to the design and synthesis of new solid-state materials sustained by covalent or noncovalent bonds with control over solid-state behaviors.