近日，西南石油大学林元华团队揭示了聚醚醚酮和聚四氟乙烯中的氢渗透机理：从实验验证到分子水平解释。2025年11月10日出版的《中国高分子科学杂志》发表了这项成果。

研究组通过实验与分子动力学模拟相结合的方式，阐明了聚醚醚酮（PEEK）和聚四氟乙烯（PTFE）中的氢传输机制，为高性能聚合物阻隔材料的性能提供了基础理论依据。实验结果表明，PEEK在常温和高温条件下均表现出优于PTFE的氢气阻隔性能。然而，分子动力学模拟揭示了一种独特的焓驱动"高溶解度-低扩散率"传输机制：尽管PEEK因更强的热力学亲和力表现出更高的氢溶解度，其扩散系数却显著低于PTFE。该机制在宽温度范围（-40°C至85°C）内持续存在，但对整体渗透率的影响具有温度依赖性。

在常温和高温条件下，PEEK的极低扩散率主导了整个渗透过程，确立了其作为高性能氢阻隔材料的有效性；而在低温（如-40°C）条件下，扩散普遍受抑制，此时PEEK的高溶解度占主导地位，导致其总渗透率超过PTFE，出现性能"反转"现象。这种独特的传输行为源于氢分子与PEEK无定形区芳香环及极性官能团之间的强非共价相互作用，该作用同时增强了溶解度并设置了显著的动力学能垒。研究组建立的"结构-机制"关联框架，为根据特定温度需求设计新一代氢阻隔材料提供了坚实的理论基础。

附：英文原文

Title: Revealing the Hydrogen Permeation Mechanism in Polyetheretherketone and Polytetrafluoroethylene: From Experimental Validation to Molecular-level Interpretation

Author: Hong-Lin Zhang, Wen-Tao Hu, Jie Xiao, Tian-Lei Li, Yuan-Hua Lin

Issue&Volume: 2025-11-10

Abstract: This study integrates experimental investigation with molecular dynamics simulations to elucidate the hydrogen transport mechanisms in polyetheretherketone (PEEK) and polytetrafluoroethylene (PTFE), offering fundamental insights into the barrier properties of high-performance polymeric materials. Experimental results demonstrate that PEEK exhibits superior hydrogen barrier performance compared to PTFE at both ambient and elevated temperatures. However, detailed molecular dynamics simulations uncover a distinctive, enthalpy-driven "high solubility-low diffusivity" transport mechanism: although PEEK displays higher hydrogen solubility due to its stronger thermodynamic affinity, its diffusion coefficient is markedly lower than that of PTFE. This mechanism remains operative across a broad operational temperature range (–40 °C to 85 °C), yet its influence on overall permeability is strongly temperature-dependent. At room and high temperatures, the exceptionally low diffusivity of PEEK governs the entire permeation process, establishing its effectiveness as a high-performance hydrogen barrier material. In contrast, under low-temperature conditions (e.g., –40°C), the general suppression of diffusion allows the high solubility of PEEK to dominate, resulting in greater overall permeability than PTFE and giving rise to a performance “reversal” phenomenon. This distinct transport behavior originates from the strong non-covalent interactions between hydrogen molecules and the aromatic rings as well as polar functional groups present in the amorphous regions of PEEK, which simultaneously enhance solubility and impose significant kinetic energy barriers. The "structure-mechanism" correlation framework established in this work provides a robust theoretical foundation for the rational design of next-generation hydrogen barrier materials tailored to specific operational temperature requirements.

DOI: 10.1007/s10118-025-3483-7

Source: https://www.cjps.org/en/article/doi/10.1007/s10118-025-3483-7/