Rates of cavity filling by liquids.
| Autor: | Seo D; Department of Chemical Engineering, University of California, Santa Barbara, CA 93106.; Department of Chemical Engineering, Brigham Young University, Provo, UT 84606., Schrader AM; Department of Chemical Engineering, University of California, Santa Barbara, CA 93106., Chen SY; Department of Chemical Engineering, University of California, Santa Barbara, CA 93106., Kaufman Y; The Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, 84990 Midreshet Ben-Gurion, Israel., Cristiani TR; Materials Department, University of California, Santa Barbara, CA 93106., Page SH; Modeling and Simulation/Computational Chemistry, The Procter & Gamble Co., West Chester, OH 45069., Koenig PH; Modeling and Simulation/Computational Chemistry, The Procter & Gamble Co., West Chester, OH 45069., Gizaw Y; Winton Hill Business Center, The Procter & Gamble Co., Cincinnati, OH 45224., Lee DW; School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, 689-798 Ulsan, Republic of Korea dongwoog.lee@unist.ac.kr jacob@engineering.ucsb.edu., Israelachvili JN; Department of Chemical Engineering, University of California, Santa Barbara, CA 93106; dongwoog.lee@unist.ac.kr jacob@engineering.ucsb.edu.; Materials Department, University of California, Santa Barbara, CA 93106. |
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| Jazyk: | angličtina |
| Zdroj: | Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2018 Aug 07; Vol. 115 (32), pp. 8070-8075. Date of Electronic Publication: 2018 Jul 19. |
| DOI: | 10.1073/pnas.1804437115 |
| Abstrakt: | Understanding the fundamental wetting behavior of liquids on surfaces with pores or cavities provides insights into the wetting phenomena associated with rough or patterned surfaces, such as skin and fabrics, as well as the development of everyday products such as ointments and paints, and industrial applications such as enhanced oil recovery and pitting during chemical mechanical polishing. We have studied, both experimentally and theoretically, the dynamics of the transitions from the unfilled/partially filled (Cassie-Baxter) wetting state to the fully filled (Wenzel) wetting state on intrinsically hydrophilic surfaces (intrinsic water contact angle <90°, where the Wenzel state is always the thermodynamically favorable state, while a temporary metastable Cassie-Baxter state can also exist) to determine the variables that control the rates of such transitions. We prepared silicon wafers with cylindrical cavities of different geometries and immersed them in bulk water. With bright-field and confocal fluorescence microscopy, we observed the details of, and the rates associated with, water penetration into the cavities from the bulk. We find that unconnected, reentrant cavities (i.e., cavities that open up below the surface) have the slowest cavity-filling rates, while connected or non-reentrant cavities undergo very rapid transitions. Using these unconnected, reentrant cavities, we identified the variables that affect cavity-filling rates: ( i ) the intrinsic contact angle, ( ii ) the concentration of dissolved air in the bulk water phase (i.e., aeration), ( iii ) the liquid volatility that determines the rate of capillary condensation inside the cavities, and ( iv ) the presence of surfactants. Competing Interests: The authors declare no conflict of interest. |
| Databáze: | MEDLINE |
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