Dual-responsive reversible colorimetric fabric with highly sensitive thermochromism via π-conjugated polydiacetylene...

Intelligent wearable materials based on polydiacetylene (PDAs) assemblies have attracted growing interest for their distinct thermochromic behavior, which arises from molecular configuration transitions. However, most conventional PDAs systems display irreversible color changes under thermal stimuli, restricting their practical utility. Herein, we developed a dual-responsive polymer by covalently linking 10,12-Pentacosadiynoic acid (PCDA) with 4,4'- diaminodiphenyl ether (ODA), followed by UV-induced polymerization. The resulting polymer ODA-functioned PCDA (poly(PCDA-ODA)) exhibits reversible color transitions from blue to red when heated between 25 and 105 °C, accompanied by a shift in crystalline layer spacing from 7.36 nm to 7.54 nm due to molecular conformational fluctuations. MXene-integrated dual-responsive (MIDR) fabric was fabricated by grafting poly(PCDA-ODA) onto modified polyester and depositing a conductive MXene layer on the reverse side. The asymmetric design enables rapid, reversible color transitions under both thermal and electrical stimuli, with response times of 0.78 s and 0.81 s, respectively. The MIDR fabric maintains excellent thermochromic reversibility up to 105 °C and demonstrates high electrothermal efficiency with distinct visual color shifts. This multifunctional fabric combines reliable thermochromic and electro-thermochromic properties across a wide temperature range, offering promising applications in visual temperature indicators.