Dynamical transition of soft porous organic nanocage: The fingerprint of water-regulated ion conduction and viscoelasticity

Water is the source of life, playing a crucial role in regulating the physiological activities of biological macromolecules. For instance, in extreme cold environments, anti-freeze proteins within organisms such as polar fish and insects inhibit ice crystal growth by binding with water molecules. Inspired by this, scientists are dedicated to exploring how to use water molecules as a key medium to endow low-cost artificial materials with similar advanced functions.

Recently, a team led by Professor Panchao Yin from the State Key Laboratory of Luminescent Materials and Devices and the South China Advanced Institute for Soft Matter Science and Technology at South China University of Technology (SCUT) published significant findings in Nano Research. Using an amine-based flexible porous organic nanocage (POC1) as a model, they deeply analyzed the hierarchical relaxation dynamics of hydrated POC1 and the regulatory mechanisms of water on material properties.

The core finding of the study lies in establishing the "dynamical transition" as fingerprint information. The researchers found that the POC1 molecule possesses a flexible framework, and the introduction of water molecules acts like a key, triggering a transformation in material properties. The team points out that confined water molecules serve not only as adsorbed guests but also as co-structural and co-dynamic elements, directly participating in and driving the spatio-temporal property changes of the entire system.

By adjusting hydration levels, the material's state can be precisely tuned from a brittle glassy state to a highly elastic rubbery state, and even to a viscous fluid. Using techniques such as Broadband Dielectric Spectroscopy (BDS) and Molecular Dynamics (MD) simulations, the study observed hierarchical relaxation dynamics. Water binds with amine groups on the cage framework, accelerating the local motion of the backbone; this microscopic "lubricating" effect ultimately leads to significant macroscopic differences in viscoelasticity and thermal properties.

This elucidation of the microscopic mechanism has directly spawned two highly promising application scenarios: First is biomimetic anti-freeze. Hydrated POC1 exhibits a thermal hysteresis effect similar to hyperactive anti-freeze proteins, effectively inhibiting ice recrystallization, which holds promise for novel anti-freeze coatings. Second is solid-state lithium-ion batteries. Increasing hydration boosts ionic conductivity by three orders of magnitude while maintaining superior mechanical flexibility, with an elongation at break reaching 180%.

Utilizing this water-regulated viscoelasticity, the team successfully developed a solid-state electrolyte for supercapacitors that demonstrates a wide, stable electrochemical window and excellent cycling performance. This research deepens the scientific understanding of nanoconfined water and proves that precise regulation of "water-material" interactions can create functional supramolecular materials for flexible electronics in extreme environments. Currently, the team is working to further enrich and optimize the POCs systems to promote their commercial application in broader energy and materials fields.

Authors Information：

Linkun Cai,^1,§ Weigang Sun,^1,§ Wenqiang You,¹ Jiadong Chen,¹ Xueying Yuan,¹ Xiupeng Chen,¹ Xian Kong,¹ Yuyan Lai,¹ and Panchao Yin^1,*

¹ State Key Laboratory of Luminescent Materials and Devices & South China Advanced Institute for Soft Matter Science and Technology, Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials, South China University of Technology

^§ Linkun Cai and Weigang Sun contributed equally to this work.

^*Address correspondence to Panchao Yin, yinpc@scut.edu.cn

We would like to thank the support from BL16B1, BL19U2, and BL10U1 of Shanghai Synchrotron Radiation Facility for the access to the synchrotron-based SAXS. This work was supported by the National Natural Science Foundation of China (Grant Nos. 22241501 and 92261117), the Guangdong-Hong Kong-Macao Joint Laboratory for Neutron Scattering Science and Technology, the Open Fund of the China Spallation Neutron Source Songshan Lake Science City (DG24313519), TCL science and technology innovation fund (Grant No. 20222056), and Guangzhou Municipal Science and Technology Bureau (No. 2023A04J1364).

DOI Link: 

https://doi.org/10.26599/NR.2026.94908366

About Nano Research

Nano Research is a peer-reviewed, open access, international and interdisciplinary research journal, sponsored by Tsinghua University and the Chinese Chemical Society, published by Tsinghua University Press on the platform SciOpen. It publishes original high-quality research and significant review articles on all aspects of nanoscience and nanotechnology, ranging from basic aspects of the science of nanoscale materials to practical applications of such materials. After 18 years of development, it has become one of the most influential academic journals in the nano field. Nano Research has published more than 1,000 papers every year from 2022, with its cumulative count surpassing 8,000 articles. In 2025 InCites Journal Citation Reports, its 2025 IF is 9.4 (8.3, 5 years), and it continues to be the Q1 area among the four subject classifications. Nano Research Award, established by Nano Research together with TUP and Springer Nature in 2013, and Nano Research Young Innovators (NR45) Awards, established by Nano Research in 2018, have become international academic awards with global influence.