岩下 靖孝
   所属   京都産業大学  理学部 物理科学科
   職種   准教授
言語種別 英語
発行・発表の年月 2014
形態種別 研究論文
査読 査読あり
標題 Orientational order of one-patch colloidal particles in two dimensions
執筆形態 その他
掲載誌名 SOFT MATTER
出版社・発行元 ROYAL SOC CHEMISTRY
巻・号・頁 10(37),pp.7170-7181
著者・共著者 Yasutaka Iwashita,Yasuyuki Kimura
概要 We studied the orientational order of one-patch colloidal particles (Janus particles) in a close-packed monolayer. In an experiment on hemispherically patched particles, we realized a highly ordered zigzag stripe pattern by inducing directional growth of the pattern via a phase transition of the solvent. Upon spontaneous ordering by strengthening the inter-patch attraction, however, the particles are trapped in a poorly ordered zigzag pattern, illustrating the importance of controlling kinetics to attain a highly ordered state. The patch-size dependence of an equilibrium orientational order is experimentally observed under moderate inter-patch attraction. We also calculated the equilibrium order against the patch size and attraction in a Monte Carlo simulation. In the simulation, the rather discrete transition between a zigzag stripe, tiling of triangular trimers and tiling of dimers under strong attraction becomes continuous with weakening attraction. The experimental result not only coincides with the simulation qualitatively but also suggests that a particular cluster is selectively formed by nonuniform inter-patch attraction in the experiment. The effect of patch-substrate attraction and commonalities of the order with liquid crystals are also discussed.
DOI 10.1039/c4sm00932k
ISSN 1744-683X/1744-6848
PMID 24989782