Characterization of polydiacetylene mixed films suitable for colorimetric and resistance based sensors

The present communication introduces a hybrid Polydiacetylene (PDA) network consisting of diacetylene (DA) monomer 10,12-pentacosadyinoic acid (PCDA) and a synthesized DA monomer N-(benzo[d]thiazol-2-yl)pentacosa-10,12-diynamide [poly(I)] using spin coating and Langmuir-Blodgett (LB) technique. The study explored various properties of the optimized PDA system, such as structural, morphological, optical, and electrical characteristics, using surface pressure-area (π-A) isotherms, atomic force microscopy (AFM), optical absorbance, and I-V characterization. The presence of modified head groups in the hybrid film strongly affects the optical and electrical properties of film, which result in distinct morphological features like irregularly sized rectangular fragments compared to pure PDAs. Additionally, the optical absorbance and I-V characteristics of the hybrid films exhibited a significant two-step colorimetric transformation (blue-purple-red) when exposed to UV irradiation followed by temperature. The hybrid film also demonstrated enhanced UV-dependent conductivity compared to pure PDA systems (PCDA and poly(I)). As whole, this study presents a modified hybrid PDA system with promising applications in optical and electrical sensing technologies.