Coupled influences of particle shape, surface property and flow hydrodynamics on rod-shaped colloid transport in porous media

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:577

Article

Ma, Huilian¹  Bolster, Carl²  Johnson, William P.¹  Li, Ke¹  Pazmino, Eddy¹  Camacho, Kathryn M.³  Anselmo, Aaron C.^3,4  Mitragotri, Samir^3,5 

[1] Univ Utah, Geol & Geophys, Salt Lake City, UT 84112 USA

[2] USDA ARS, Bowling Green, KY 42104 USA

[3] Univ Calif Santa Barbara, Chem Engn, Santa Barbara, CA 93106 USA

[4] Univ N Carolina, Div Pharmacoengn & Mol Pharmaceut, Eshelman Sch Pharm, Chapel Hill, NC 27599 USA

[5] Harvard Univ, Sch Engn & Appl Sci, Cambridge, MA 02138 USA

关键词: Colloid transport;    Porous media;    Rod-shaped particles;    Shape effect;    Particle rotation;   

DOI  :  10.1016/j.jcis.2020.05.022

来源: Elsevier

【 摘 要 】

Hypothesis: Natural or engineered colloidal particles are often non-spherical in shape. In contrast to the widely-used homogeneous sphere assumption, the non-spherical particle shape is expected to alter particle-fluid-surface interactions, which in turn affect particle transport and retention. Experiments and Simulations: Polystyrene microspheres were stretched to rod-shaped particles of two aspect ratios (2:1, 6:1). The transport and retention behaviors of rods versus spheres were investigated in packed quartz sand columns and impinging jet systems. In parallel, a 3D trajectory model was employed to simulate particle translation and rotation, and to elucidate the role and underlying mechanisms of particle shape impact on transport. Findings: Rods were observed to undergo rotating and tumbling motions in response to fluid shear from experiments and simulations. However, no distinct retention trends between rods and spheres were observed from column studies, despite BSA-coating on particles, Fe-coating on sand or velocity change. This was primarily due to the super-hydrophobic nature of colloid surfaces acquired from stretching process, which in hydrophilic sand columns, dominated particle-surface charge interactions. Simulations using colloids with randomly distributed charge patches qualitatively produced the observed insensitivity in retention respecting aspect ratio under low charge coverage (<30%). Hence, particle shape influences were strongly coupled with colloid surface properties and flow hydrodynamics. (C) 2020 Elsevier Inc. All rights reserved.

【 授权许可】

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