中国科学院理化技术研究所王树涛团队揭示纳米颗粒致密悬浮液的热反应干扰对宏观液体-固体可转换材料的影响。该项研究成果于2021年11月22日在线发表在《德国应用化学》杂志上。

研究人员发现，SiO2 -PNIPAAm纳米颗粒（SPNP）通过热响应干扰的可逆无序聚集，获得了智能液-固切换材料。这种智能材料可以显示出对温度变化的反应，在类液态和类固态之间切换。这种独特的宏观行为源于可逆的无序聚集，由SPNP之间随温度变化的疏水相互作用所调节。

值得注意的是，这些处于类固体状态的材料显示出抗冲击性，可以承受速度为328厘米/秒的钢球冲击。研究人员认为，这一发现为设计智能液固转换材料提供了灵感，可实现对冲击的保护。

据悉，用于构建功能材料的纳米粒子聚集在各种应用中显示出巨大的优势。大多数努力都集中在针对特定功能的有序纳米粒子聚集上，但由于热力学平衡的原因，往往局限于不可逆的聚集过程。

附：英文原文

Title: Thermo-Responsive Jamming of Nanoparticle Dense Suspensions towards Macroscopic Liquid-Solid Switchable Materials

Author: Mingqian Liu, Xizi Wan, Man Yang, Zhao Wang, Han Bao, Bing Dai, Huan Liu, Shutao Wang

Issue&Volume: 2021-11-22

Abstract: Abstract: Nanoparticle aggregation for constructing functional materials has shown enormous advantages in various applications. Most efforts focused on ordered nanoparticle aggregation for specific functions but often limited in irreversible aggregation processes due to the thermodynamic equilibrium. Herein, we report a reversible disordered aggregation of SiO  2  -PNIPAAm nanoparticles (SPNPs) through thermo-responsive jamming, obtaining smart liquid-solid switchable materials. The smart materials can display a switch between liquid-like state and solid-like state responding to temperature change. This unique macroscopic behavior originates from the reversible disordered aggregation modulated by temperature-dependent hydrophobic interactions among the SPNPs. Notably, the materials at solid-like state show anti-impact property and can withstand the impact of a steel sphere with a speed of 328 cm/s. We envision that this finding offers inspirations to design smart liquid-solid switchable materials for impact protection.

DOI: 10.1002/anie.202114602

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202114602