Separation of Caustic Nano-Emulsions and Macromolecular Conformations with Nanofibrous Membranes of Marine Chitin

Sustainable development of nanotechnology is challenged by nanoscale pollutants and oily water. Biobased nanoporous membranes, though serving as one of the most eco-friendly separation technologies, cannot be applied widely because of their broad pore distributions, poor solvent resistance, and structural instability. In order to avoid possible leakage of nanoscale objects in caustic and organic solvents, herein, we endeavored to exfoliate chitin nanofibrils with identical chemical and crystalline structures to pristine chitin in portunid carapace and further produce nanoporous and mesoporous membranes with super structural stability, endurance, permeation flux and rejection. The final membranes had minimal ionization, controllable thickness, and tunable and narrow distribution of pore size, being able to separate nano-emulsions, nanoparticles, and rigid macromolecules in caustic aqueous solutions and organic solvents. Thus, these scalable, low-cost, and sustainable membranes may promise applications as diverse as in separating and concentrating nanoparticles in nanotechnology, oil/water separation in wastewater treatment, and molecular sieving in biomedicine and material science.