Pool Boiling Performance on Cu-TiO ₂ Nanoparticle-Coated Copper Surfaces Prepared Through Hybrid Method

In large-scale, high-heat industrial applications, surfaces obtained using efficient and cost-effective methods are highly desirable. In this paper, the surfaces are modified through two-step processes, i.e., a chemical etching process to grow CuO thin film on bare copper (Cu) surfaces, and then a Cu-TiO2 composite nanoparticle is deposited over the CuO thin-film copper surface through electrochemical deposition. The experiment is conducted on both the prepared surfaces and the bare Cu surface using deionized water as a boiling fluid. Results reveal that the prepared surfaces exhibit better pool boiling performance than the bare Cu surface due to improved properties like porosity and roughness. The critical heat flux and boiling heat transfer coefficient are found to have 61 and 72% enhancement, respectively, compared to bare copper surfaces. Bubble behavior during boiling is also captured and analyzed for all surfaces through a high-speed camera.