Kalantar-Zadeh Kourosh, Tang Jianbo, Daeneke Torben, O'Mullane Anthony P, Stewart Logan A, Liu Jing, Majidi Carmel, Ruoff Rodney S, Weiss Paul S, Dickey Michael D
School of Chemical Engineering , University of New South Wales (UNSW) , Kensington , New South Wales 2052 , Australia.
School of Engineering , RMIT University , Melbourne , Victoria 3000 , Australia.
ACS Nano. 2019 Jul 23;13(7):7388-7395. doi: 10.1021/acsnano.9b04843. Epub 2019 Jun 27.
Bulk liquid metals have prospective applications as soft and fluid electrical and thermal conductors in electronic and optical devices, composites, microfluidics, robotics, and metallurgy with unique opportunities for processing, chemistry, and function. Yet liquid metals' great potential in nanotechnology remains in its infancy. Although work to date focuses primarily on Ga, Hg, and their alloys, to expand the field, we define "liquid metals" as metals and alloys with melting points (mp) up to 330 °C, readily accessible and processable even using household kitchen appliances. Such a definition encompasses a family of metals-including the majority of post-transition metals and Zn group elements (excluding Zn itself)-with remarkable versatility in chemistry, physics, and engineering. These liquid alloys can create metallic compounds of different morphologies, compositions, and properties, thereby enabling control over nanoscale phenomena. In addition, the presence of electronic and ionic "pools" within the bulk of liquid metals, as well as deviation from classical metallurgy on the surfaces of liquid metals, provides opportunities for gaining new capabilities in nanotechnology. For example, the bulk and surfaces of liquid metals can be used as reaction media for creating and manipulating nanomaterials, promoting reactions, or controlling crystallization of dissolved species. Interestingly, liquid metals have enormous surface tensions, yet the tension can be tuned electrically over a wide range or modified surface species, such as the native oxides. The ability to control the interfacial tension allows these liquids to be readily reduced in size to the nanoscale. The liquid nature of such nanoparticles enables shape-reconfigurable structures, the creation of soft metallic nanocomposites, and the dissolution or dispersion of other materials within (or on) the metal to produce multiphasic or heterostructure particles. This Perspective highlights the salient features of these materials and seeks to raise awareness of future opportunities to understand and to utilize liquid metals for nanotechnology.
大块液态金属作为柔软且可流动的电导体和热导体，在电子和光学器件、复合材料、微流体、机器人技术及冶金领域具有潜在应用价值，在加工、化学及功能方面拥有独特机遇。然而，液态金属在纳米技术领域的巨大潜力仍处于起步阶段。尽管迄今为止的研究主要集中在镓、汞及其合金上，但为了拓展该领域，我们将“液态金属”定义为熔点（mp）高达330°C的金属和合金，即使使用家用厨房器具也易于获取和加工。这样的定义涵盖了一族金属，包括大多数后过渡金属和锌族元素（不包括锌本身），它们在化学、物理和工程方面具有显著的多功能性。这些液态合金能够形成具有不同形态、成分和性质的金属化合物，从而实现对纳米级现象的控制。此外，大块液态金属内部存在电子和离子“库”，以及液态金属表面偏离经典冶金学的现象，为在纳米技术中获得新能力提供了机会。例如，液态金属的大块和表面可作为反应介质，用于制备和操纵纳米材料、促进反应或控制溶解物种的结晶。有趣的是，液态金属具有巨大的表面张力，但这种张力可通过电方式在很宽的范围内调节，或通过改变表面物种（如原生氧化物）来调节。控制界面张力的能力使这些液体能够很容易地缩小到纳米尺度。这种纳米颗粒的液态性质使得能够形成形状可重构的结构、制备柔软的金属纳米复合材料，以及使其他材料在金属内部（或表面）溶解或分散，从而产生多相或异质结构颗粒。本综述强调了这些材料的显著特征，并旨在提高人们对未来理解和利用液态金属进行纳米技术研究机会的认识。
