Investigation of atmospheric moisture interaction on modified copper surfaces using thermoelectric cooling

Abstract

Atmospheric moisture extraction is crucial for rectifying two key challenges: 1) reducing atmospheric temperature through greenhouse gas effects and 2) alleviating drinking water scarcity. Various methods for extracting atmospheric moisture, such as condensation, porous metal-organic frameworks (MOFs), covalent organic frameworks (COFs), and hygroscopic aerogels, have been explored to address this issue. In this study, four types of copper surfaces (bare, treated, SA-modified, and AA-SA-modified) were prepared using a solution immersion method. These surfaces were characterized using field-emission scanning electron microscopy with energy-dispersive X-ray spectroscopy (FE-SEM with EDAX), X-ray Diffraction (XRD), Attenuated Total Reflectance Infrared Spectroscopy (ATR-IR), and contact angle measurements. Water droplet absorption experiments were conducted at an atmospheric relative humidity variation of 50–53 % with laboratory and condensation surface temperature variations of 29.9–31 °C and 9–9.6 °C, respectively, using a Peltier thermoelectric cooling setup. The absorption tests were performed at 15-minute intervals (over four cycles) using simple tissue paper as the absorbent. The AA-SA-modified copper surface exhibited the highest atmospheric moisture interaction (36.36 %) during the first 15 min compared to the other surfaces owing to its optimal surface energy. Additionally, the shapes of the water droplets and their absorption mechanisms on the AA-SA-modified surface were analyzed. Overall, this study demonstrates that the AA-SA-modified copper surface has significant potential for atmospheric moisture extraction under various humidity conditions.