Plastic crystals (PCs), formed by certain types of molecules or ions with reorientational freedom, offer both exceptional mechanical plasticity and long range order, hence they are attractive for many mechano-adaptable technologies. While most classic PCs belong to simple globular molecular systems, a vast number of examples in the literature with diverse geometrical (cylindrical, bent, disk, etc.) and chemical (neutral, ionic, etc.) natures have proven their wide scope and opportunities. All the recent reviews on PCs aim to provide insights into a particular application, for instance, organic plastic crystal electrolytes or ferroelectrics. This tutorial review presents a holistic view of PCs by unifying the recent excellent progress in fundamental concepts from diverse areas as well as comparing them with liquid crystals, amphidynamic crystals, ordered crystals, etc. We cover the molecular and structural origins of the unique characteristics of PCs, such as exceptional plasticity, facile reversible switching of order-to-disorder states and associated colossal heat changes, and diffusion of ions/molecules, and their attractive applications in solid electrolytes, opto-electronics, ferroeletrics, piezoelectrics, pyroelectrics, barocalorics, magnetics, nonlinear optics, and so on. The recent progress not only demonstrates the diversity of scientific areas in which PCs are gaining attention but also the opportunities one can exploit using a crystal engineering approach, for example, the design of novel dynamic functional soft materials for future use in flexible devices or soft-robotic machines.

中文翻译：

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利用塑料晶体中的分子旋转：适应性软材料的晶体工程的整体视图

由某些类型的具有独立方向性的分子或离子形成的塑料晶体（PC）具有出色的机械可塑性和远距离有序性，因此它们对许多适用于机械的技术具有吸引力。虽然大多数经典PC属于简单的球状分子系统，但文献中的大量示例具有不同的几何形状（圆柱，弯曲，圆盘等）和化学形状（中性，离子等）。）自然已经证明了它们的广泛范围和机会。最近有关PC的所有评论旨在提供对特定应用的见解，例如，有机塑料晶体电解质或铁电体。本教程综述通过统一来自不同领域的基本概念的最新出色进展，并将它们与液晶，两性晶体，有序晶体等进行比较，从而提供了PC的整体视图。我们涵盖了PC独有特性的分子和结构起源，例如出色的可塑性，易于实现的有序状态和相关的巨大热变化的可逆转换，离子/分子的扩散以及它们在固体电解质中的诱人应用，光电，铁电，压电，热电，压力，磁性，非线性光学等等。最近的进展不仅证明了PC正在引起人们关注的科学领域的多样性，而且还表明了人们可以使用晶体工程方法开发的机会，例如，设计新颖的动态功能性软材料以供将来用于柔性设备或软硬件中。机器人机器。