Materials Chemistry and Physics 241 (2020) 122349 Available online 23 October 2019 0254-0584/© 2019 Elsevier B.V. All rights reserved. The electrochromic device performance with DNA based electrolyte Gratiela Teodora Tihan a , Mihaela Mindroiu a , Ileana Rau a , Lucas Marinho N� obrega de Assis b , Agnieszka Pawlicka b , Roxana Gabriela Zgarian a, * a Faculty of Applied Chemistry and Materials Science, University POLITEHNICA of Bucharest, Polizu Street No. 1, 011061, Bucharest, Romania b IQSC-Universidade de S~ ao Paulo, Av. Trabalhador Saocarlense 400, 13566-590, S~ ao Carlos, SP, Brazil HIGHLIGHTS G R A P H I C A L ABSTRACT � A new DNA-LiClO 4 based SPE was ob- tained and investigated in an ECD. � Two working electrodes: PB and WO 3 were tested in an ECD. � The results showed that ECD-PB is slightly stable than ECD-WO 3 device. A R T I C L E INFO Keywords: Electrochromism Prussian blue WO 3 DNA polymer electrolyte Electrochromic devices ABSTRACT The infuence of the DNA based electrolyte on the electrochromic device performance designed with two different working electrodes is presented. The novelty of the present research consists in the use of DNA membrane with different LiClO 4 ratios in order to achieve new electrochromic windows with good performances. For this purpose, two different working electrodes and the same counter electrode were used and compared for assembling different devices as glass/ITO/Prussian Blue (PB)/DNA membrane/CeO 2 –TiO 2 /ITO/glass and glass/ ITO/WO 3 /DNA membrane/CeO 2 –TiO 2 /ITO/glass. The main goal is to fnd the optimum LiClO 4 ratio into the membrane’s composition, which promotes the best ionic conductivity required for a good ECD performance. In the selection of the best DNA membrane the FT-IR, UV-VIS spectroscopy, and the ionic conductivity results were used. The two working electrodes were analyzed by contact angle and surface free energy. The electrochromic devices were evaluated by charge density measurements, cyclic voltammetry, and chronoamperometric cycling coupled with UV-VIS spectroscopy. The obtained results showed that the best composition of the DNA based membranes is 1 wt% of LiClO 4 (DNA1GLY1LP1), and the electrochemical and spectroscopic performance of ECDs were similar for PB and WO 3 as working electrodes. Nevertheless, the Prussian Blue electrode showed an almost constant transmission variation after a number of consecutive cycles of colour change. * Corresponding author. Faculty of Applied Chemistry and Materials Science, Polizu Street No 1, 011061, Bucharest, Romania. E-mail address: roxana.zgarian@upb.ro (R.G. Zgarian). Contents lists available at ScienceDirect Materials Chemistry and Physics journal homepage: www.elsevier.com/locate/matchemphys https://doi.org/10.1016/j.matchemphys.2019.122349 Received 26 June 2019; Received in revised form 15 October 2019; Accepted 22 October 2019