https://scholar.dgist.ac.kr/handle/20.500.11750/11791 2026-10-27T07:04:38Z https://scholar.dgist.ac.kr/handle/20.500.11750/60989 Title: All Bio-Based Noncorrosive Hygroscopic Hydrogel Enables Passive Cooling of Electronic Devices Author(s): Kim, Hyeondo; Hwang, Deok Jun; Kim, Na Kyung; Kang, Taewon; Kim, Soobeen; Kim, Seong Kyun Abstract: The emergence of artificial intelligence (AI) technologies has greatly increased the importance of thermal management in electronic systems. Conventional cooling strategies require substantial amounts of coolant, particularly water, whose demand is rapidly increasing. Here, we propose a sorption-based passive evaporative cooling system using an all-nature-derived hygroscopic polymer film, which can supplement conventional cooling systems and substantially reduce their energy consumption. In a simulated laboratory-scale demonstration, the system achieved a maximum cooling power of (), with a maximum temperature reduction of 18.2 degrees C. The cooling performance was also maintained during repeated cyclic simulations. In addition, the incorporation of an organic ionic liquid as a hygroscopic component, instead of conventional metal salts, endowed the film with excellent flexibility, elongation, adhesiveness, and noncorrosive properties. Therefore, the proposed sorption-based passive cooling system holds great potential for assisting conventional electronic cooling systems while significantly reducing energy demand. 2026-08-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/59057 Title: A Water-Efficient Artificial Phytoextraction Technology for the Remediation of Cesium-Contaminated Soil Inspired by Plant Transpiration and the Hydrologic Cycle Author(s): Kim, Soobeen; Hwang, Deok Jun; Kim, Hyeondo; Lim, Hongsub; Kim, Seong Kyun Abstract: Cesium ions (Cs+) are notable radioactive contaminants hazardous to humans and the environment. Among various remediation methods, adsorption is a practical way to remove Cs+ from water, and Prussian blue (PB) is well-known as an efficient Cs+ adsorbent. Although various PB derivatives have been proposed to treat Cs+-contaminated water, soil remediation is still challenging due to the limited mobility of pollutants in soil. Here, we proposed a water-efficient artificial phytoextraction system integrated with a plant-like interfacial solar vapor generation (ISVG) device for remediation of Cs+-contaminated soil. The leaf of the device consisting of PB immobilized on cellulose nanofiber (CNF-PB) endows the device with the abilities of accumulation of Cs+ as well as solar-to-thermal conversion for water evaporation. The proposed remediation system showed significant Cs+ removal ability from contaminated agricultural soil under actual sunlight, with no additional water required due to the system's water-recycling capability. The device can be readily revived by replacing the Cs+ accumulated leaf with a new one, and the used adsorbent can be easily regenerated by acid washing for reuse. Thus, the proposed system is a sustainable, fast, and eco-friendly soil remediation strategy for Cs+ contamination. 2025-08-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/58492 Title: Maximizing the practical performance of a solar vapor generation system by optimizing vapor flow over the evaporation surface Author(s): Hwang, Deok Jun; Kim, Hyeondo; Kim, Soobeen; Kang, Taewon; Kim, Seong Kyun Abstract: Interfacial solar vapor generation (ISVG) has received significant attention as a promising solution to the global water scarcity problem. Various evaporation systems with high performance have been developed over the past few years, and solar energy-to-vapor conversion efficiencies have been enhanced through a variety of strategies. However, most of these studies have primarily focused on improving the performance of individual evaporators. In practical desalination applications, multiple evaporators need to be integrated into a single solar still, where they can influence one another through environmental heat acquisition and vapor convection above the evaporation surfaces. In this study, the inter-evaporator interactions affecting evaporation performance were systematically investigated. For short evaporators, environmental heat acquisition predominantly governs the system performance. In contrast, for taller evaporators, vapor flow between the evaporators plays a more significant role. Both environmental heat acquisition and vapor convection between neighboring evaporators are strongly influenced by the height of the evaporators and the spacing between them. Therefore, careful optimization of both evaporator height and spacing is essential to maximize the overall performance of ISVG systems in practical desalination applications. © 2025 Elsevier B.V. 2025-09-30T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/57329 Title: A systematic study of the evaporation performance of column-type 3D solar evaporators with variations in the surrounding temperatures Author(s): Kim, Hyeondo; Lim, Hongsub; Hwang, Deok Jun; Kim, Soobeen; Kang, Taewon; Kim, Seong Kyun Abstract: Interfacial solar vapor generation has received much attention as a promising solution to the water scarcity problem. Various evaporation systems capable of significant performance have been developed over the past few years, and solar energy-to-vapor limitations can be overcome by adopting the concept of a three-dimensional (3D) evaporator, enabling the use of surrounding energy in the evaporation process. The degree of surrounding energy utilization depends on the temperature difference between the surrounding air and the evaporation surface, and the air temperature in a solar still – which is indispensable in practical applications – is much higher than the ambient temperature. Laboratory-based evaporation experiments involving a group of 3D column-type evaporators with various surrounding air temperatures were conducted systematically using a newly designed system capable of controlling the surrounding air temperature. The evaporation behaviors at elevated temperatures show significant correspondence with those collected from indoor and outdoor evaporation experiments with a solar still. Therefore, the evaporation performance capabilities of 3D evaporators in practical applications using a solar still can be quantitatively evaluated by investigating laboratory-based evaporation experiments at correspondingly elevated surrounding temperatures. © 2024 Elsevier B.V. 2024-11-30T15:00:00Z