Multi-reversible thermochromic polydiacetylene-CuZnFe<inf>2</inf>O<inf>4</inf> magnetic nanocomposites with tunable colorimetric response to acid-base

Abstract

Polydiacetylenes (PDAs) are materials that can be applied as colorimetric sensors for detecting a wide range of stimuli. The commercial PDA materials, constituting carboxylic headgroup, exhibit irreversible thermochromism and response to base. To extend the utilization, their sensing properties are often tuned by structural modification of PDA headgroup and/or side chain. In this study, we introduce a versatile method for fine tuning the properties of polydiacetylene (PDA) materials by incorporating CuZnFe2O4 magnetic nanoparticles. The resultant PDA/CuZnFe2O4 magnetic nanocomposites (MNCs) exhibit multi-reversible thermochromism with different shades of color transition. The MNCs also response to both acid and base. In addition, the sensitivity can be tuned by varying CuZnFe2O4 ratio. The PDA/CuZnFe2O4-MNCs are localizable via the application of magnetic field. These multifunctional MNCs show potential in various advanced technologies such as smart paints, anti-counterfeiting labels, electro-thermochromic displays and localizable acid/base sensors. The preparing process of MNCs is rather simple, making it suitable for industrial utilization.