Facile synthesis of P(EDOT/Ani) : PSS with enhanced heat shielding efficiency via two-stage shot growth

Poly(3,4-ethylenedioxythiophene/aniline) : poly(styrene sulfonate), P(EDOT/Ani) : PSS, with enhanced absorption of near infrared light, was prepared by oxidative polymerization. We demonstrated that a two-stage shot growth process optimizes the absorption of the polymer in the near infrared region via a controlled monomer addition time. In other words, the optical properties of the polymer complex were improved by controlling the time intervals of aniline monomer addition. P(EDOT/Ani) : PSS was characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The shielding efficiency of the P(EDOT/Ani) : PSS films was calculated by using data from ultraviolet, visible, and near infrared (UV-vis-NIR) spectroscopy. The introduction of polyaniline to PEDOT increased the absorption in the near infrared area. In comparison with PEDOT : PSS film, the total shielding efficiency of the P(EDOT/Ani) : PSS film increased to 65.8% from 54.6% at 60% transmittance. The maximum NIR shielding efficiency (SE(NIR)) of the film is 92.7% and the transmittance is 46.5%. Also, large-scale P(EDOT/Ani) : PSS film was fabricated using roll-to-roll slot-die equipment and a heat shielding test of the film was conducted by measuring the temperature variation, in order to prove the enhanced heat shielding effect. P(EDOT/Ani) : PSS prepared by a two-stage shot growth system showed excellent potential as a heat shielding material.