水同位素分离和识别是医学、化学及生命科学等领域的关键技术。水（H2O) and heavy water (D2O）的分子尺寸及宏观理化性质高度相似，在多孔介质中的平衡吸附差异有限，仅凭终态吸附量难以判定同位素差异缘由。因此，构建兼具取向窄孔道、适度框架柔性和质子—电子耦合传导的薄膜，并通过质量与电学信号协同解析多阶段传输过程，是实现实时识别水同位素限域行为的关键。
Recently, scientific research teams such as the Institute of Process Engineering of the Chinese Academy of Sciences have achieved H2O和D2O在限域空间中多阶段传输行为的实时区分，并观测到独特的序列依赖非对称同位素置换现象。
The team used octahydroxytetraphenylbenzene (TPB), which is non-planar, flexible and rich in hydrophobic units, as a ligand and used self-developed spray-type layer-by-layer self-assembly (LbL) technology to prepare a CuTPB film with oriented narrow channels and proton-electron coupling conduction characteristics. Synchrotron radiation grazing incidence wide-angle X-ray scattering and theoretical calculations confirmed that the film channels are mainly arranged along the normal direction of the film, and electron transport is mainly in the direction of the film plane.
On this basis, the team independently built a comprehensive quality-electrical dual conduction testing platform. The MEMS resonant microcantilever analyzes the adsorption mass and kinetic stages. The chemical resistance sensor uses the proton-electron coupling conduction characteristics of the film to convert rapid hydration of the outer surface, migration in the pores, and guest-framework reorganization into distinguishable multi-stage current signals. The two types of independent signals corroborate each other in terms of dynamic stages and isotope change trends, achieving real-time analysis of the transfer process of water isotopes from the outer surface to the pores.
in D2O/H2In the O sequential exposure experiment, the electrical displacement factor α of the CuTPB film reached 7.0 at 20% relative humidity. Combining infrared spectroscopy, X-ray diffraction and other general-purpose high spatiotemporal resolution in-situ operating condition cell characterization and molecular dynamics simulations, the study found that relatively durable D2O-confined hydrogen bonding state can inhibit subsequent H2The slow phase adsorption and recombination of O produces an obvious sequence-dependent asymmetric isotope replacement response.
该研究为扩散调控材料设计与同位素分离过程实时监测提供了方法基础。
Relevant research results were published in "German Applied Chemistry" (Angewandte Chemie International Edition)superior.研究工作得到国家自然科学基金委员会、中国科学院等的支持。
Multi-stage transport of water isotopes and proton-electron coupling electrical response mechanism in oriented conductive MOF films
Source: https://www.cas.cn/syky/202609/t20260904_5119719.shtml