Key Lab of Organic Optoelectronics & Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing100084, China.
Institute of Smart City and Intelligent Transportation, Southwest Jiaotong University, Chengdu610032, China.
J Am Chem Soc. 2023 Feb 15;145(6):3526-3534. doi: 10.1021/jacs.2c12133. Epub 2023 Jan 31.
Dynamic supramolecular networks are constantly accompanied by thermal instability. The fundamental reason is most reversible noncovalent bonds quickly decay at elevated temperatures and dissociate below 100 °C. Here, in this paper, we realize a reversible ion-dipole interaction with high-temperature stability exceeding 150 °C. The resultant supramolecular network can simultaneously possess mechanical strength of 1.32 MPa (14.8 times that of pristine material), dynamic self-healing capability, and a stable working temperature of up to 200 °C. From the prolonged characteristic relaxation time of 600 s even at 100 °C, our material represents one of the most thermally stable dynamic supramolecular polymers. These remarkable performances are achieved by using a new multivalent yet low-entropy-penalty molecular design. In this way, the noncovalent bond can reach a high enthalpy while minimizing the entropy-dominated thermal dissociations.
动态超分子网络总是伴随着热不稳定性。其根本原因是大多数可逆非共价键在高温下迅速衰减，并在 100°C 以下解离。在本文中，我们实现了一种具有超过 150°C 的高温稳定性的可逆离子偶极相互作用。所得的超分子网络同时具有 1.32 MPa 的机械强度（比原始材料高 14.8 倍）、动态自修复能力和高达 200°C 的稳定工作温度。从在 100°C 时甚至长达 600 s 的延长特征弛豫时间来看，我们的材料代表了最稳定的热动态超分子聚合物之一。通过使用新的多价但低熵惩罚分子设计，实现了这些显著的性能。通过这种方式，非共价键可以达到高焓，同时使熵主导的热分解最小化。
