Flow-induced 2D nanomaterials intercalated aligned bacterial cellulose.

Bacterial cellulose is a promising biodegradable alternative to synthetic polymers due to the robust mechanical properties of its  nano-fibrillar building blocks. However, its full potential of mechanical properties remains unrealized, primarily due to the challenge of aligning nanofibrils at the macroscale. Additionally, the limited diffusion of other nano-fillers within the three-dimensional nanofibrillar network impedes the development of multifunctional bacterial cellulose-based nanosheets. Here, we report a simple, single-step, and scalable bottom-up strategy to biosynthesize robust bacterial cellulose sheets with aligned nanofibrils and bacterial cellulose-based multifunctional hybrid nanosheets using shear forces from fluid flow in a rotational culture device. The resulting bacterial cellulose sheets display high tensile strength (up to ~ 436 MPa), flexibility, foldability, optical transparency, and long-term mechanical stability. By incorporating boron nitride nanosheets into the liquid nutrient media, we fabricate bacterial cellulose-boron nitride hybrid nanosheets with even better mechanical properties (tensile strength up to ~ 553 MPa) and thermal properties (three times faster rate of heat dissipation compared to control samples). This biofabrication approach yielding aligned, strong, and multifunctional bacterial cellulose sheets would pave the way towards applications in structural materials, thermal management, packaging, textiles, green electronics, and energy storage.