Suppression of Coffee Ring Effect by Controlling Morphology of Particle Aggregate

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K15075
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 27010:Transport phenomena and unit operations-related
• Research Institution: Okayama University
• Principal Investigator: Mino Yasushi 岡山大学, 自然科学学域, 助教 (70709922)
• Project Period (FY): 2020-04-01 – 2022-03-31
• Keywords: 粒子懸濁液 / 乾燥 / コーヒーリング現象 / 格子ボルツマン法

Outline of Final Research Achievements

In this study, the methods to suppress the coffee ring phenomena were explored experimentally and numerically. We experimentally observed that the formation of characteristic ring-like deposits was suppressed when the particles aggregated by the addition of KCl. Furthermore, we found that the particulate aggregates also suppressed the cracking of particulate film during the evaporation of solvent. In order to understand the particle dynamics, the numerical simulation method for solid-liquid-vapor three-phase system was developed. Using this numerical method, we simulated the particle deposition during the solvent evaporation, and demonstrated that the particles forming aggregates were not transported freely and formed loosely-packed film.

Free Research Field

化学工学

Academic Significance and Societal Importance of the Research Achievements

粒子を含む液体を乾燥させて粒子膜を得るプロセスにおいて、コーヒーリング現象は普遍的に生じる問題である。そのため、本研究で得られた知見は化学工業分野だけでなく、食品や医療・バイオといった幅広い分野で利用することができる。また、開発したシミュレーション技術は本研究に限らず, 固-気-液の三相系に関する様々な複雑現象を解明するための手段として用いることが可能である。