Biodegradable long-persistent luminescent films based on PHB/PHBV as matrix and sunlight conversion applications

Multifunctional chromone-incorporated poly(hydroxybutyrate) luminescent film for active and intelligent food packaging

The major objective of present work was to fabricate poly(hydroxybutyrate) based luminescent films for genuine food packaging applications. These films were synthesized by incorporating varying Chromone (CH) concentrations (5, 10, 15, 20, and 25 wt%) into poly(hydroxybutyrate) (PHB) matrix through solvent-casting. Different characteristics of prepared films were examined using Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Thermogravimetric analysis (TGA), Mechanical testing, and Time-resolved photoluminescence (TRPL). UV-blocking properties and water vapor permeation were also examined. FTIR spectra indicated the occurrence of hydrogen bonding between PHB and CH. Among all prepared film samples, PHB/CH15 showed maximum tensile strength (22.5 MPa) with enhanced barrier ability against water vapor and UV rays, thermal stability, and luminescent performance. After overall analysis, PHB/CH15 film was selected to investigate its X-ray diffraction, release behavior, DPPH scavenging, and antimicrobial potential. Release kinetics revealed that the cumulative release percentage of CH was higher in fatty acid stimulant. Moreover, results suggested that this film demonstrated antioxidant activity (>55 %) and superior antimicrobial potential against Aspergillus niger, Staphylococcus aureus, and Escherichia coli. Furthermore, packaging of bread samples using PHB/CH15 film demonstrated the complete inhibition of microbial growth in bread up to 10 days of storage and ensure the safety of genuine food products.