Hydrophilic SiO2 nanoparticle deposition on boiling surface: Molecular dynamics insights into deposition behavior and heat transfer performance

Abstract

Because of its outstanding heat transfer performance, boiling phenomenon is widely used in heat dissipation of electronic devices. Despite its boiling enhancement effect, the inclusion of nanoparticle in boiling process leads to severe deposition, showing nonnegligible impact on heat transfer coefficient. However, existing studies lack the analysis on its inherent mechanism from microscale deposition behavior to macroscale boiling performance. In this study, a hydrophilic SiO₂ nanoparticle is investigated in typical boiling conditions, while its deposition process and accompanying effect on boiling performance are analyzed. The boiling process on copper substrates with heating temperature from 460 K to 520 K is simulated via molecular dynamics. At temperature above 500 K, over 96 % of water evaporates within 15 ns, leading to the formation of a dense deposited SiO₂ layer, and thus hindering further water evaporation. Cross-sectional density profiles demonstrate the water evaporation hindering by this deposited layer. Radial distribution functions and OSiO bond‑angle distributions peaking at 108.5° confirm short‑range structural ordering at the interface, without any abnormal bond breakage observed. This deposition layer reduces the interfacial thermal resistance by 70.91 % at 520 K, while correspondingly increasing heat transfer coefficient by 243.86 % for constant heating-temperature condition. The circumstance under constant heat flux is also discussed, with quantitative comparison with existing data. These molecular-scale findings offer new insights into the discovery of nano-altered heat transfer mechanism, promote thermal management for high-power microprocessors, and contribute to the advancement of emerging energy technologies.