热烈祝贺我团队博士生王峰、李维研究员等撰写的论文“Anticorrosive Magnetic Microwave Absorbers by Turbulent Sol-Gel Method”被期刊Journal of Materials Science & Technology（2023年IF：11.2，中科院一区TOP期刊）接收！
在微米级粒子表面包覆均匀、致密和薄的纳米壳层，对于众多应用领域，特别是耐腐蚀的宽带微波吸收材料（MAMs），具有举足轻重的意义。然而，目前仍缺乏有效的加工技术来实现这一目标。鉴于此，本研究开发了一种湍流辅助的溶胶-凝胶法，实现微米级片状羰基铁（FCI）表面包覆均匀、致密的SiO2纳米壳层。在该方法中，毫米级氧化锆球在轨道振动驱动下会挤压溶液，与液体介质产生显著的相对运动，进而引发强烈的湍流加速SiO2在FCI粒子表面的非均相成核，提升成核密度，生成均匀致密的SiO2纳米壳层。这样制备的核壳结构粒子能够最小化界面极化，在保持较高的磁损耗的同时，具有优化的阻抗匹配，能表现出增强的电磁吸收特性和防腐性能。用它构建的填充型复合材料在厚度为1 mm时，低于-10 dB的反射损耗带宽达到6.5 GHz；同时它们的防腐性能也实现了数量级的显著提升。本研究提出的湍流溶胶-凝胶法为制备兼具耐腐蚀性、宽频带吸收能力和薄层的MAMs提供了一种极具潜力的新方法。该技术不仅操作简便，而且效率高，为在微米级粒子表面构建均匀致密的纳米壳层开辟了一条有效途径。
原文摘要如下：Coating uniform, compact and thin nanoshells on micro-sized particles is critical to various applications including anticorrosive broadband microwave absorbing materials (MAMs), yet effective processing methods remain lacking. In this work, a turbulent sol-gel method is developed to coat the desired SiO2 nanoshells on flaky carbonyl iron (FCI) particles. The adding millimeter-sized zirconia balls, driven by the orbital shaking, squeeze the solution and create significant relative motion between the liquid and balls, which generates turbulent flows. This significantly promotes the heterogeneous nucleation rate and high nucleation density, ultimately forming highly compact and uniform SiO2 nanoshells covering FCI particles to enhance the electromagnetic absorption and anticorrosion properties. The as-obtained core-shell particles minimize the interface polarization and retain high magnetic loss, resulting in an improved impedance matching and a reflection loss < -10 dB with a bandwidth of 6.5 GHz at a thin thickness of 1 mm. Moreover, they also show a substantial order-of-magnitude improvement in anticorrosion performance. This work provides a promising method to fabricate anticorrosive, broadband and thin-thickness MAMs. The turbulent sol-gel method developed herein offers a facile and effective approach for fabricating uniform compact nanoshells on micro-sized particles.
