Chen Lian-Yi, Xu Jia-Quan, Choi Hongseok, Konishi Hiromi, Jin Song, Li Xiao-Chun
1] Department of Mechanical and Aerospace Engineering, University of California at Los Angeles, Los Angeles, California 90095, USA [2] Materials Science Program, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA [3] Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
1] Department of Mechanical and Aerospace Engineering, University of California at Los Angeles, Los Angeles, California 90095, USA [2] Materials Science Program, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
Nat Commun. 2014 May 9;5:3879. doi: 10.1038/ncomms4879.
Effective control of phase growth under harsh conditions (such as high temperature, highly conductive liquids or high growth rate), where surfactants are unstable or ineffective, is still a long-standing challenge. Here we show a general approach for rapid control of diffusional growth through nanoparticle self-assembly on the fast-growing phase during cooling. After phase nucleation, the nanoparticles spontaneously assemble, within a few milliseconds, as a thin coating on the growing phase to block/limit diffusion, resulting in a uniformly dispersed phase orders of magnitude smaller than samples without nanoparticles. The effectiveness of this approach is demonstrated in both inorganic (immiscible alloy and eutectic alloy) and organic materials. Our approach overcomes the microstructure refinement limit set by the fast phase growth during cooling and breaks the inherent limitations of surfactants for growth control. Considering the growing availability of numerous types and sizes of nanoparticles, the nanoparticle-enabled growth control will find broad applications.
在表面活性剂不稳定或无效的苛刻条件下（如高温、高导电性液体或高生长速率）有效控制相生长，仍然是一个长期存在的挑战。在此，我们展示了一种通用方法，通过在冷却过程中在快速生长的相上进行纳米颗粒自组装来快速控制扩散生长。在相核化之后，纳米颗粒在几毫秒内自发组装，在生长相上形成一层薄涂层以阻止/限制扩散，从而产生比没有纳米颗粒的样品小几个数量级的均匀分散相。这种方法在无机材料（不混溶合金和共晶合金）和有机材料中均得到了验证。我们的方法克服了冷却过程中快速相生长所设定的微观结构细化限制，并打破了表面活性剂用于生长控制的固有局限性。考虑到各种类型和尺寸的纳米颗粒越来越容易获得，基于纳米颗粒的生长控制将有广泛的应用。
