LEAPS-MPS: Investigation of Electrochromic Polymer Induced Plasmon Switching on Gold Nanocrystals and its Application for Smart Windows

In this project, funded by the Chemistry Division at NSF, Professor Gang Chen and his students at the University of Central Florida will perform studies that aim to integrate electrochromic polymer with plasmonic nanoparticles to build a new type of smart windows with improved performance. Smart windows, whose transmittance/reflection of sunlight can be selectively adjusted, can dramatically improve the comfortability and security of living, and drastically reduce the energy consumptions of air conditioning in buildings and automobile vehicles. The performance of smart windows mainly depends on chromic materials, and polymer electrochromic materials are of great commercial value because of their high coloration efficiency, fast response speed, and high processability. However, electrochromic polymers will deteriorate under high applied electrochemical potentials. The deterioration will affect their long-term cyclability and lower their color contrast, which prevents the commercialization of the polymer electrochromic materials. Professor Chen and his students will tackle this challenge by developing hybrid materials consisting of plasmonic nanoparticle and electrochromic polymer that can be used to fabricate smart-window devices with improved color-switching characteristics. This project intends to expose smart materials research for a new generation so that they will take a leading role in future scientific innovation. Prof. Chen plans to involve graduate and undergraduate students, especially underrepresented minority students in STEM fields, as well as high school students in the project to broaden the integration of research and participation-oriented outreach activities. Plasmonic nanoparticles, including gold, silver, and copper, have strong light absorption and scattering at their plasmon wavelengths, which can be synthetically tuned from visible to near infrared. The plasmonic properties are strongly dependent on their dielectric environments and thereafter can be easily varied by the dielectric change brought by the transition between bleached and colored states of electrochromic polymer. The introduction of plasmonic nanoparticles is expected to largely improve the color contrast of electrochromic polymer under different states and therefore avoid its possible electrochemical deterioration. This study will further our understanding on electrochromic polymer-induced plasmonic switching behaviors of plasmonic nanoparticles. Smart-window devices fabricated from plasmonic nanoparticles/electrochromic polymer hybrid nanostructures are expected to have improved color-switching characteristics. The knowledge gained from this study will also be useful for designing many other plasmon-based optical devices for controlling and directing light for a wide range of areas such as information displays, anti-counterfeiting inks, and photothermal systems for cancer therapy. 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.