Session: 11-10-04: Radiative Heat Transfer Across Scales

Paper Number: 146008

146008 - Manufacturing, Characterization and Terrestrial Passive Radiative Cooling Performance of Nanofibrous Ptfe-Peo Composite Thermal Coatings 

Passive heat management is desirable in many applications since it can reduce the energy expended for cooling, for example, in buildings and automobiles. Specifically, materials with wavelength-dependent reflectance and emittance can manage incident solar fluxes while enabling passive radiative cooling by thermal emission. This study demonstrates the use of polymeric nanofibers, specifically polytetrafluoroethylene (PTFE) and polyethylene oxide (PEO) composite, as thermal coatings for passive temperature control. Employing the electrospinning fabrication process, we engineer nano and micro-scale fibrous structures, studying the influence of fabrication parameters, such as precursor material concentration and rotating collector speed, on fiber geometry and optical properties. To understand the role of material and fiber geometry on optical performance, we characterize various samples' spectral reflectance, absorptance, and transmittance using spectrophotometers interfaced with integrating spheres. The results show the potential of nanofabricated PTFE-PEO coatings as promising candidates for passive thermal control. We highlight their competitive edge by comparing their solar reflectance and emittance values to existing passive radiative thermal control materials. In essence, this study contributes to advancing passive heat management technologies, offering insights into optimizing material composition and fabrication techniques for enhanced performance in various applications.

 

 

Passive heat management is desirable in many applications since it can reduce the energy expended for cooling, for example, in buildings and automobiles. Specifically, materials with wavelength-dependent reflectance and emittance can manage incident solar fluxes while enabling passive radiative cooling by thermal emission. This study demonstrates the use of polymeric nanofibers, specifically polytetrafluoroethylene (PTFE) and polyethylene oxide (PEO) composite, as thermal coatings for passive temperature control. Employing the electrospinning fabrication process, we engineer nano and micro-scale fibrous structures, studying the influence of fabrication parameters, such as precursor material concentration and rotating collector speed, on fiber geometry and optical properties. To understand the role of material and fiber geometry on optical performance, we characterize various samples' spectral reflectance, absorptance, and transmittance using spectrophotometers interfaced with integrating spheres. The results show the potential of nanofabricated PTFE-PEO coatings as promising candidates for passive thermal control. We highlight their competitive edge by comparing their solar reflectance and emittance values to existing passive radiative thermal control materials. In essence, this study contributes to advancing passive heat management technologies, offering insights into optimizing material composition and fabrication techniques for enhanced performance in various applications.

 

 

Passive heat management is desirable in many applications since it can reduce the energy expended for cooling, for example, in buildings and automobiles. Specifically, materials with wavelength-dependent reflectance and emittance can manage incident solar fluxes while enabling passive radiative cooling by thermal emission. This study demonstrates the use of polymeric nanofibers, specifically polytetrafluoroethylene (PTFE) and polyethylene oxide (PEO) composite, as thermal coatings for passive temperature control. Employing the electrospinning fabrication process, we engineer nano and micro-scale fibrous structures, studying the influence of fabrication parameters, such as precursor material concentration and rotating collector speed, on fiber geometry and optical properties. To understand the role of material and fiber geometry on optical performance, we characterize various samples' spectral reflectance, absorptance, and transmittance using spectrophotometers interfaced with integrating spheres. The results show the potential of nanofabricated PTFE-PEO coatings as promising candidates for passive thermal control. We highlight their competitive edge by comparing their solar reflectance and emittance values to existing passive radiative thermal control materials. In essence, this study contributes to advancing passive heat management technologies, offering insights into optimizing material composition and fabrication techniques for enhanced performance in various applications.

Presenting Author: Chieloka Ibekwe Rensselaer Polytechnic Institute

Presenting Author Biography: Chieloka Ibekwe is a 3rd year Mechanical Engineering PhD Student at Rensselaer Polytechnic Institute, Troy New York. He is passionate about thermal management of systems, advanced manufacturing and energy conversion systems. His current research is focuses on passive radiative thermal control materials in space and Earth applications.

Authors:

Chieloka Ibekwe Rensselaer Polytechnic Institute
Xuanjie Wang Rensselaer Polytechnic Institute
Jason Hartwig` NASA Glenn Research Center
Adam Swanger NASA Kennedy Space Center
Shankar Narayan Rensselaer Polytechnic Institute