Multi‐Scaled Cellulosic Nanonetworks from Tunicates

Abstract The selective removal of non‐cellulosics from microbial biofilms and particularly plants has enabled the formation of high‐performance yet sustainable functional materials. However, ascidians, the only animals to synthesize cellulose nanofibers, have not been explored for their cellulosic nanonetworks. In this work, the removal of non‐cellulosics from ascidians through mild processes yields a cellulose nanonetwork with features that cannot be obtained from either plants or microbes. The obtained “nano‐ascidian” has nanofibers structured into spherical capsules with a diameter of ≈50 µm bound by an extracellular matrix spanning across the entire tissue, which is convoluted with a 3D fractal network of capillaries ranging from 50 to 500 µm in diameter. The obtained nanonetwork is showcased for potential fluidics operation, highlighting domain‐segregated infusion and functionalization by leveraging the vascularized structures present. Unique features associated with the innate cellulose‐protein composition are put forward, including an outstanding strain at a break of 48%. Finally, the upcycling of ascidian into nanonetworks of cellulose as an ecosystem preservation tool for managing both native and invasive ascidian species is proposed. Overall, by providing a third‐class, animal‐based, of cellulosic nanonetworks, the study offers a new platform for advanced nanocellulosics uniquely associated with a global and sustainable coastal blue bioeconomy.