Effect of Wet-Stretching and Confinement on Fiber Alignment in Bacterial Cellulose Films

Recent progress in sustainable materials has provided viable solutions to address the escalating challenges posed by non-renewable sourcing, environmentally harmful manufacturing processes, and the ultimate fate of synthetic plastics. Within this context, biopolymers have garnered increasing interest for their potential as eco-friendly substitutes to petroleum-derived counterparts, offering the distinct advantage of reduced environmental impact across their entire lifecycle. Bacterial cellulose (BC) stands out as a particularly compelling candidate, combining a high molecular weight, high degree of crystallinity, and a scalable, adaptable biosynthetic manufacturing process. Unlike plant-derived cellulose, BC circumvents the need for extensive extraction procedures, rendering it more accessible and environmentally benign. Following drying, the naturally grown BC hydrogels, called pellicles, can be transformed into self-supporting, lightweight yet mechanically robust films with prospective applications in structural panels or protective garments. This study delves into the effect of mechanical stretching/confinement as means of aligning the fibers in BC pellicles and their impact on the overall mechanics of the resulting dried films, aiming to offer fundamental insights into the structure-property interplay of this networked polymer. The results will not only enrich our fundamental understanding of polymer physics pertaining to BC-based networks, but also pave the way for future tailoring of the properties of the resulting films to cater to a diverse array of applications.