Organogel-based coating for energy saving in maritime and building

Abstract

Organogel, a gel-like polymer material capable of absorbing and swelling when exposed to oil molecules, serves as the foundation for the development of novel coatings with unique properties. In this thesis, three innovative coating concepts were proposed: Oil-Entangled Matrix (OEM), Photothermal Oil-Entangled Matrix (POEM, an extension of OEM), and Thermal Responsive Organogel Polymer Encapsulation (TROPE). These coatings aim to address energy consumption challenges in both marine vehicles and buildings. OEM and POEM offer a slippery interface that effectively reduces drag when water flows over them, thereby minimizing energy consumption associated with drag resistance. Remarkably, these coatings achieved a maximum drag reduction of 48% in water tunnel tests, comparable to existing superhydrophobic surfaces or lubricant-infused porous surfaces. Additionally, the slippery interface exhibits low ice adhesion (< 11 kPa), significantly reduces frost accretion (up to 68%), and mitigates bacterial adhesion (by 70% to 90%). These properties address additional operational challenges faced by maritime vehicles. On the other hand, TROPE introduces a novel thermochromic mechanism that enables passive regulation of solar absorptance in response to temperature variations. This mechanism allows the coating to modify its absorptance contrast, reaching up to 0.25. Notably, this performance is comparable to existing thermochromic dyes, such as leuco dyes and vanadium dioxide. Furthermore, TROPE demonstrates excellent durability under UV radiation and thermal cycles, making it a viable coating option for external walls and roofs of buildings. This technology can achieve potential savings of up to 3% in annual heating, ventilation, and air conditioning (HVAC) energy consumption. The findings presented in this thesis highlight the significant contribution of organogel-based coating strategies and materials towards energy conservation in maritime and building applications. By addressing key challenges and providing sustainable solutions, these coatings have the potential to contribute to the overall sustainability of our society.

Date of Award	2024
Original language	English
Awarding Institution	The Hong Kong University of Science and Technology
Supervisor	Shuhuai YAO (Supervisor)