Atomic armor for thermal stability in nanoporous structures

• 成果类型: Article
• 署名作者: Yang, Rui; Si, Qiaoling; Sheng, Qiang; Yang, Mingyang; Du, Mu; Zhang, Hu; Shi, Xiao-Lei; Tang, Guihua; Chen, Zhi-Gang
• 署名单位: Xi'an Jiaotong University; Shandong University; Xi'an Jiaotong University; Queensland University of Technology (QUT); Queensland University of Technology (QUT)
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-13103
• DOI: 10.1073/pnas.2510746122
• 发表日期: 2025-09-09
• 关键词: silica aerogels

摘要

Nanoporous structures play a critical role in a wide range of applications, including catalysis, thermoelectrics, energy storage, gas adsorption, and thermal insulation. However, their thermal instability remains a persistent challenge. Inspired by the extraordinary resilience of tardigrades, an atomic armor strategy is introduced to enhance the stability of nanoporous structures. Applied to mesoporous silica at parts-per-million levels, the atomic armor provides thermal resistance exceeding that of existing stabilization techniques. Thermal treatment at 1,000 degrees C for 168 h results in a fivefold increase in specific surface area, 66% lower thermal conductivity, and a sixfold increase in pore volume compared to untreated samples. Surface viscosity is linked to sintering resistance, and glass transition temperature and fragility are introduced as design parameters. Machine-learned interatomic potentials and metabasin escape algorithm-assisted molecular dynamics simulations are employed to reveal that materials traditionally classified as nonglass formers can exhibit glass transition temperatures and display intrinsic fragility. Alumina is identified as having a record-high glass transition temperature. By modulating the surface viscosity of nanoparticles, this approach stabilizes nanoporous structures effectively. The proposed method offers a simple and universal posttreatment process for improving the thermal stability of nanoporous structures.