近日，北京大学张锦团队报道了0.5%石墨烯削减38.8°C的塑料晶体过冷。相关论文于2025年11月5日发表在《美国化学会志》上。

塑料晶体因其可逆的"有序-无序"相变在热管理领域前景广阔，但高能势垒引发的显著过冷现象常制约其应用。

研究组通过向三羟甲基氨基甲烷（Tris）中引入0.5 wt%石墨烯，在提升焓值20.8%的同时实现38.8°C的过冷抑制。关键机制在于石墨烯诱导的"转动熵钉扎"效应，在增加焓值的同时使熵值降低40.3%。该效应源于定向转动约束与协同氢键晶格重构。借助同步辐射X射线衍射、飞秒红外光谱及分子动力学模拟，研究组捕捉到从飞秒级分子振动到宏观晶格重组的结构演化。

这一突破规避了成核效率与储能容量之间的经典矛盾，其普适性更延伸至塑料晶体体系及固液相变架构。相关发现提出的界面约束转动动力学模型，为设计超低滞后、高能量密度材料开辟新径。石墨烯兼具成核促进剂与分子有序模板的双重功能，该机制在其他塑料晶体体系中得到验证，为解决过冷难题与提升储能性能提供了普适性策略，推动塑料晶体向高效固态热管理领域迈进。

附：英文原文

Title: 0.5% Graphene Slashed 38.8 °C Supercooling in Plastic Crystals

Author: Xinyu Zhang, Liang Xu, Yanyan Shao, Xudan Huang, Zhenyun Zhao, Fachen Liu, He Hao, Weiyu Sun, Ning Cao, Junliang Sun, Lin Qiu, Peng Gao, Lei Liu, Hailin Peng, Lifen Wang, Yunliang Li, Tao Cheng, Yuanlong Shao, Jin Zhang

Issue&Volume: November 5, 2025

Abstract: Plastic crystals are promising for thermal management due to their reversible order–disorder phase transitions, but they often face challenges with significant supercooling caused by high energy barriers. We address this challenge by incorporating 0.5 wt % graphene into tris(hydroxymethyl)aminomethane (Tris), resulting in a 38.8 °C supercooling inhibition while boosting enthalpy by 20.8%. The pivotal role of graphene induces “rotational entropy pinning”, achieving a 40.3% reduction in entropy alongside a simultaneous enthalpy increase. This effect is rooted in directional rotation confinement and cooperative hydrogen-bond lattice reconstruction. Employing synchrotron XRD, femtosecond IR spectroscopy, and MD simulations, we capture structural transformations from femtosecond molecular vibrations to macroscopic lattice reorganization. This advancement circumvents the classical trade-off between nucleation efficiency and energy storage capacity, extending its universality to plastic crystalline systems and even solid–liquid phase-change architectures. These insights propose an interface-confined rotational dynamics model, heralding a leap in designing ultralow-hysteresis, high-energy-density materials. This dual role of graphene as both a nucleation promoter and molecular ordering template, validated in other plastic crystal systems, provides a universal strategy to suppress supercooling while enhancing energy storage, which advances plastic crystals toward efficient solid-state thermal regulation.

DOI: 10.1021/jacs.5c06886

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.5c06886