3D-printed PLA/PEO blend as biodegradable substrate coating with CoCl2 for colorimetric humidity detection

This study aimed to fabricate biodegradable substrate with colorimetric humidity indicator for detective moisture in food packaging. The poor properties of poly(lactic acid) (PLA) were enhanced by melt blending PLA non-toxic poly(ethylene oxide) PEO at 180 °C. Specifically, three-dimensional (3D) substrates PLA/PEO blends fabricated solvent-cast 3D printing. Furthermore, cobalt chloride (CoCl2) solution was printed onto the an inkjet printer serve as a sensing indicator. It found that flexibility and thermal stability improved hydrophilicity increased increase content. Color changes sensitivity this material confirmed using image analysis total color difference. CoCl2 displayed ranged from blue pink under ambient conditions (above 60%RH), revealing suitable potential frozen packaging aim detect amount