Professor Zhengzhong Shao and coworkers at Fudan University published an interesting paper entitled “Ultrafast and Reversible Thermochromism of Conjugated Polymer Material Based on Assembling of Peptide Amphiphiles” in Chemical Science on 2 July 2014. This is a cooperative research study with Professor David Porter from Oxford University in UK and Doctor Dennis Löwik from Radboud University in the Netherlands. Hui Guo, a PhD student of Fudan University, is the first author of this paper.

The translation of colour change in chameleon to synthetic functional materials has attracted increasing interests, and conjugated polymers such as polydiacetylenes that undergo chromatic transitions under heating represent one of the most studied systems. However, they suffer a slow and irreversible colour change typically at low temperatures, e.g., 50-90 °C, which limits their sensing applications. In addition, they appear in powders or films and cannot satisfy the wearable electronics, a mainstream direction in sensing. Herein, the introduction of peptide to the side chain enables a continuous polydiacetylene fibre that exhibits ultrafast, reversible thermochromatic transitions at a high temperature up to 200 °C. In particular, the reversible thermochromism occurs even at a temperature change rate of 5000 K/s, much higher than typically ~1 K/s of the other sensing polymers. The formation of a hierarchically assembled structure is responsible for this remarkable chromatism. In addition, a general and effective model is discovered to quantitatively predict the critical temperature of the colour change in polydiacetylene and guide the development of chromatic materials.

The thermochromic materials and the principle diagram

More information: http://pubs.rsc.org/en/content/articlelanding/2014/sc/c4sc01696c