Synthesis and application of spherical colloids with visible rotational motion

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K17734
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Biological physics/Chemical physics/Soft matter physics
• Research Institution: The University of Tokyo
• Principal Investigator: Yanagishima Taiki 東京大学, 生産技術研究所, 特任研究員 (00716699)
• Research Collaborator: RUSSO John ブリストル大学, 数学部, Lecturer ; LIU Yanyan オックスフォード大学, 物理化学部 ; TANAKA Hajime 東京大学, 生産技術研究所, 教授 (60159019) ; DULLENS Roel オックスフォード大学, 物理化学部, 教授
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: コロイド / 流体 / ダイナミクス

Outline of Final Research Achievements

Colloidal systems consist of microscopic particles tens of nanometers to microns in size, suspended in a liquid medium. Optical microscopy can be used to locate single particles and directly observe structural change. However, when the particles are spherical, it is not possible to observe the rotational motion of single particles, despite rotation being a sensitive degree of freedom to fluid flow in dense suspensions. The aim of this project was to synthesise spherical particles with an anisotropic fluorescence. The original plan was to use a　plastic material, but this did not prove successful. Instead, a silane coupling agent was used to create a particle with a small core of the same material but different color embedded just below the particle surface. We thus realised colloidal particles whose rotational Brownian motion was easily visible using confocal microscopy, even in dense systems. These particles also hold promise as a probe for shear flow at the micron scale.

Free Research Field

ソフトマター物理学