2023-03-30 ノースウェスタン大学
従来、研究者たちは原子や10倍〜100倍程度大きいコロイドの自己結合を観察してきたが、この研究により、両者の中間的な大きさを持つナノ粒子の自己結合も観測することができた。
研究は、イリノイ大学とノースウェスタン大学が中心となって行われ、3月30日にNature Nanotechnologyに掲載された。
＜関連情報＞
- https://news.northwestern.edu/stories/2023/03/watch-nanoparticles-grow-into-crystals/
- https://www.nature.com/articles/s41565-023-01355-w
ナノ粒子の結晶成長を解き明かす Unravelling crystal growth of nanoparticles
Binbin Luo,Ziwei Wang,Tine Curk,Garrett Watson,Chang Liu,Ahyoung Kim,Zihao Ou,Erik Luijten & Qian Chen
Nature Nanotechnology Published:30 March 2023
DOI:https://doi.org/10.1038/s41565-023-01355-w
Abstract
Crystal growth from nanoscale constituents is a ubiquitous phenomenon in biology, geology and materials science. Numerous studies have focused on understanding the onset of nucleation and on producing high-quality crystals by empirically sampling constituents with different attributes and varying the growth conditions. However, the kinetics of post-nucleation growth processes, an important determinant of crystal morphology and properties, have remained underexplored due to experimental challenges associated with real-space imaging at the nanoscale. Here we report the imaging of the crystal growth of nanoparticles of different shapes using liquid-phase transmission electron microscopy, resolving both lateral and perpendicular growth of crystal layers by tracking individual nanoparticles. We observe that these nanoscale systems exhibit layer-by-layer growth, typical of atomic crystallization, as well as rough growth prevalent in colloidal systems. Surprisingly, the lateral and perpendicular growth modes can be independently controlled, resulting in two mixed crystallization modes that, until now, have received only scant attention. Combining analytical considerations with molecular dynamics and kinetic Monte Carlo simulations, we develop a comprehensive framework for our observations, which are fundamentally determined by the size and shape of the building blocks. These insights unify the understanding of crystal growth across four orders of magnitude in particle size and suggest novel pathways to crystal engineering.
