The Effect of Adsorbed Volatile Organic Compounds on an Ultrathin Water Film Measurement

• Published in: Applied sciences Vol. 10; no. 17; p. 5981
• Main Authors: Ahangar, Shahab Bayani, Jeong, Chan Ho, Long, Fei, Allen, Jeffrey S., Lee, Seong Hyuk, Choi, Chang Kyoung
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.09.2020; MDPI
• Subjects: Acetone; Adsorption; Air plasma; Atomic force microscopy; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; Cleaning; Contact angle; Deionization; dropwise condensation; ENGINEERING; Gold coatings; Humidity; Hydrocarbons; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Isopropanol; Isopropyl alcohol; Light microscopy; MATERIALS SCIENCE; Microscopy; monolayer; Monolayers; nucleation; Optical microscopy; Organic compounds; Photoelectrons; Physics; Plasma; Surface chemistry; surface homogeneity; Surface plasmon resonance; Surface roughness; surface treatment; thin film measurement; Thin films; VOCs; Volatile organic compounds; Water film; XPS; United States > US
• ISSN: 2076-3417; 2076-3417
• DOI: 10.3390/app10175981

Using surface plasmon resonance imaging (SPRi), we have recently shown for the first time the existence of a monolayer water film between droplets during dropwise condensation. This study examines the effect of adsorbed volatile organic compounds (VOCs) on the ultrathin film measurement using SPRi. Further, the work presents the proper surface-treatment process that enables measurements of the ultrathin water layer during high-speed imaging of dropwise condensation at 3000 frame per second. In this study, two methods were applied for cleaning the surface (gold-coated glass)—(1) standard cleaning procedure (SCP) using acetone, isopropyl alcohol, and deionized water and (2) SCP followed by air plasma cleaning. This work discusses the effect of the cleaning procedures on surface roughness, contact angle, and surface chemistry using atomic force microscopy, optical microscopy, and an X-ray photoelectron spectroscope meter. The results showed that SCP before the SPRi is a proper surface-treatment method. The effect of adsorbed VOCs during dropwise condensation on a surface treated with SCP was measured to be 0.0025 (reflectivity unit), which was 70% smaller than the reflectance associated with a monolayer water film. The results of this work confirm a monolayer water film observation during the dropwise condensation, which has been reported before.