Real-time 3D monitoring of NIR laser effects on biodegradable polymers

We present the real-time 3D monitoring of NIR laser exposure effects on biodegradable Starch/Kefiran/ZnO nanocomposites polymers using a compact and robust digital holographic microscopy (DHM) arrangement in transmission mode. These biodegradable nanocomposites are of particular interest for food packaging due to their antimicrobial activity and extended shelf-life performance. Our DHM approach facilitates precise 3D imaging, allowing for the detailed observation of subtle structural changes being induced by NIR exposure. Through systematic reconstruction of the recorded digital holograms, we quantify the morphological response of the biopolymers and the local temperature variations within them. Our results reveal that NIR exposure smooths the nanocomposite surface through thermally driven morphological rearrangement, which may enhance the film's hydrophilicity and thereby increase its susceptibility to environmental degradation pathways. This integrated DHM-NIR platform offers a promising bench-top tool for in situ analysis of microstructural and thermal dynamics in a wide spectrum of materials.