Effect of Geometric and Chemical Anisotropy of Janus Ellipsoids on Janus Boundary Mismatch at the Fluid-Fluid Interface
| Autor: | Bum Jun Park, Kang Dong Woo, Woong Ko, Bomsock Lee |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Janus particles
02 engineering and technology 010402 general chemistry lcsh:Technology 01 natural sciences Article Physics::Fluid Dynamics Janus particle fluid-fluid interface attachment energy configuration Janus boundary Metastability General Materials Science Janus lcsh:Microscopy Anisotropy lcsh:QC120-168.85 Phase diagram lcsh:QH201-278.5 Condensed matter physics fluid–fluid interface lcsh:T Chemistry 021001 nanoscience & nanotechnology Critical value 0104 chemical sciences Condensed Matter::Soft Condensed Matter Classical mechanics lcsh:TA1-2040 Particle lcsh:Descriptive and experimental mechanics lcsh:Electrical engineering. Electronics. Nuclear engineering Wetting lcsh:Engineering (General). Civil engineering (General) 0210 nano-technology lcsh:TK1-9971 |
| Zdroj: | Materials Materials; Volume 9; Issue 8; Pages: 664 MATERIALS(9): 8 Materials, Vol 9, Iss 8, p 664 (2016) |
| ISSN: | 1996-1944 |
| Popis: | We investigated the geometric and chemical factors of nonspherical Janus particles (i.e., Janus ellipsoids) with regard to the pinning and unpinning behaviors of the Janus boundary at the oil-water interface using attachment energy numerical calculations. The geometric factors were characterized by aspect ratio (AR) and location of the Janus boundary (alpha) separating the polar and apolar regions of the particle. The chemical factor indicated the supplementary wettability (beta) of the two sides of the particle with identical deviations of apolarity and polarity from neutral wetting. These two factors competed with each other to determine particle configurations at the interface. In general, the critical value of beta (beta(c)) required to preserve the pinned configuration was inversely proportional to the values of alpha and AR. From the numerical calculations, the empirical relationship of the parameter values of Janus ellipsoids was found; that is, lambda = Delta beta(c)/Delta alpha approximate to 0.61AR - 1.61. Particularly for the Janus ellipsoids with AR > 1, the beta(c) value is consistent with the boundary between the tilted only and the tilted equilibrium/upright metastable region in their configuration phase diagram. We believe that this work performed at the single particle level offers a fundamental understanding of the manipulation of interparticle interactions and control of the rheological properties of particle-laden interfaces when particles are used as solid surfactants. |
| Databáze: | OpenAIRE |
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