Enhanced Radiative Cooling Performance in P(VDF-TrFE) Copolymer Based on Phononic Properties

Abstract

Passive radiative cooling technology is realized by increasing solar reflection and infrared emission. Polymer materials demonstrate greater potential in multi-scenario cooling applications due to their excellent flexibility and manufacturability. Intrinsic characteristic modification is crucial for enhancing the performance of materials. Here, the radiative cooling properties of PVDF and P(VDF-TrFE) with different C─F content are evaluated. Theoretical studies based on first-principles calculations are conducted to understand the screening of chemical bonds from phonon dispersions. Then the optical performances are tested, with P(VDF-TrFE) showing an enhanced net cooling power of 41% and 21% during daytime and nighttime, respectively. On-site measurements have also been conducted. Compared to PVDF, the average cooling temperature drops of P(VDF-TrFE) increase from 7.2 to 8.5 °C at noon and from 2.1 to 3.5 °C at night. This work successfully bridges atomic-scale characteristics with material-level radiative performance, providing a reference for finding effective radiative cooling materials through phononic properties.