Dr. Dino Megaridis has just received a new NSF award for the project “Collaborative Research: A Micropatterned Wettability Approach for Superior Boiling Heat Transfer Performance.”
This is a collaborative grant with Iowa State University and UIC’s share (with Dino as the only participant) is $151,826.
PIs: Daniel Attinger (Iowa State Univ.) and C. Megaridis (UIC)
The high heat transfer rates attained by boiling are necessary in many industrial applications that require high performance. Consequently, innovations in materials and processes for cost-effective and high performance boiling heat transfer are of immense interest. This collaborative project will develop a science base for the fabrication, modeling and optimization of a new class of surfaces for technical heat transfer materials. These surfaces juxtapose superhydrophobic and superhydrophilic regions, to induce a strong dual affinity for vapor and liquid. Hence, we call these surfaces superbiphilic. Preliminary collaborative work by the PIs has shown that superbiphilic surfaces are ideally suited to control multiphase heat transfer processes, with e.g. measured critical heat fluxes over 100 W/cm2 and heat transfer coefficients over 100 kW/m2K, in water pool boiling tests.
Superbiphilic surfaces will be fabricated on technical materials (metals) by a novel process based on sprayed-on polysilsesquioxane-silica composite coatings. These coatings are inherently superhydrophobic and become superhydrophilic by CO2 laser processing at the micrometer scale. The performance of the superbiphilic surfaces will be characterized by wettability measurements, coating characterization, nucleation curves and pool boiling experiments. The work will determine how the multiscale geometry and wettability of superbiphilic surfaces influences the boiling heat transfer rates of water. The boiling enhancement will be analyzed by coupling analytical and numerical techniques with experiments of pool boiling and high-speed visualization. The wettability and topography of the hydrophobic and hydrophilic regions (spots, lines, etc.) will be optimized by coupling theoretical models with a higher-level optimization framework.
The work will advance discovery and fundamental understanding, while promoting teaching, training, and learning by means of a parallel education/outreach component that involves underprivileged high-school students in Chicago. Graduate and undergraduate students who will be involved in the research will serve as mentors to the high-school students.