A green approach for delignification of corn husks and their application as an unpowered thermo-responsive sensor

The world is adopting biodegradable materials to replace existing petroleum-based plastics, owing to their toxicity and unfriendly environmental aspects. Biodegradable corn husk (CH) is considered a promising alternative due to its environmental friendliness and widespread availability as agricultural waste. In this work, a green process for the delignification of corn husk was developed and preparation of CH-based reversible thermo-responsive delignified corn husk (RTDCH) sensors was done which exhibit different colors corresponding to particular temperature ranges. These RTDCH sensors employed with reversible thermo-responsive nanoparticles (RTNPs) were characterized thoroughly using X-ray Diffraction (XRD), scanning electron microscopy (SEM), thermo-gravimetric analysis (TGA), and Fourier transform spectroscopy (FTIR), which ensures their successful synthesis. Upon deploying them for sensing temperatures from 20 to 80℃, different color displays appeared rapidly within 5 seconds, which helps to identify the particular temperature range. The RTDCH exhibited excellent reusability for several cycles and maintained consistency in color displays at certain exposed temperatures. The RTDCH, being unpowered, fast responsive, accurate, biodegradable, economical, and scalable production feasibilities, has the necessary traits to become practical at the industrial level. Such materials have tremendous potential for the food industry, scientific laboratories, and monitoring the temperature of industrial processes. The strategy adopted in this work is crucial since it is paving the way for the development of advanced functional materials from natural wastes through green synthesis approaches.