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 with non-toxic poly(ethylene oxide) PEO at 180 °C. Specifically, three-dimensional (3D) substrates of PLA/PEO blends were fabricated by solvent-cast 3D printing. Furthermore, cobalt chloride (CoCl2) solution was printed onto the substrate with an inkjet printer to serve as a colorimetric humidity sensing indicator. It found that the flexibility and thermal stability of the PLA were improved and the hydrophilicity was increased with an increase in PEO content. Color changes and the sensitivity of this material were confirmed using image analysis and total color difference. The CoCl2 indicator displayed color changes that ranged from blue to pink under ambient conditions (above 60%RH), revealing suitable potential for frozen food packaging material with aim to detect amount of moisture in the packaging.
|Number of pages||10|
|Journal||Food Packaging and Shelf Life|
|Early online date||17 Feb 2022|
|Publication status||Published - Jun 2022|
Bibliographical note© 2022, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
Funding: This research was financially supported by the Program Management Unit for Human Resources & Institutional Development, Research and Innovation, Office of National Higher Education Science Research and Innovation Policy Council (NXPO), Thailand [Grant Number B16F640001]; National Electronics, Computer Technology Center (NECTEC), National Science and Technology Development Agency (NSTDA), Thailand; the Center for Innovation in Chemistry (PERCH-CIC) and the Center of Excellence in Materials Science and Technology, Chiang Mai University, Thailand. This project also received funding from the European Union's Horizon 2020 Research and Innovation Programme under Marie Sklodowska-Curie grant agreement No. 871650 (MEDIPOL).