Evaporation and condensation processes are central to water desalination, power generation, heating, air-conditioning, and manufacturing. Improving and controlling the characteristics of the liquid-vapor phase-change can enhance the performance and the overall efficiency of these applications. One of the techniques to enhance phase-change is by incorporating nanomaterials or nanostructures. However, implementation of this technique so far has primarily been trial-based, by comparisons of applications with and without nanostructures. The overall goal of this NSF CAREER project is to integrate research and education around the use of nanoengineered materials to enhance and control evaporation and condensation. This project will determine and quantify the role of various factors that affect phase-change on smooth and textured surfaces. The education objectives of this project are to equip students and the future workforce with the technical knowledge and skill sets to innovate and build transformative and sustainable systems for power generation, energy storage, and water desalination. The project also aims to increase the participation of students in science, technology, engineering, and mathematics by providing extended research opportunities and augmented reality instruction to excite students about energy transfer mechanisms and their applications in the industry.
Although phase-change and vapor transport at the macroscale are fairly well understood, they show unique characteristics in nanostructures. Understanding these characteristics is essential to leverage nanomaterials in industrial applications. The proposed project will allow elucidating phase-change and vapor transport at the nanoscale by using a novel experimental technique combining a piezoelectric mass and area-sensing mechanism, visualization, and infrared thermography. This approach allows detecting mass changes with high sensitivity, accuracy, and repeatability. The project will generate a new understanding of how geometry and surface chemistry of nanostructures control liquid-vapor phase-change and vapor transport. The research will address the effect of non-idealities on phase-change. These non-idealities include non-volatile impurities in the liquid phase and non-condensable gases in the vapor phase. Although such non-idealities are ubiquitous, prior efforts have primarily focused on evaporation and condensation of pure fluids. Direct measurements of phase-change will also test the accuracy of the classic models used to predict evaporation and condensation within nanostructures.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
