Gas responsive cellulose fibers for capturing and releasing of dyes and proteins from water by packing a smart separation column

Separation of dyes and proteins from water remains a significant challenge. Common absorbents without recyclability might bring secondary pollutions, which may be avoided by developing stimuli-responsive smart absorbents. Here in this work, a CO2-responsive polymer poly(2-(dimethylamino) ethyl methacrylate) was grafted from cellulose fibers (Cell-g-PDEA). The chemical structure and surface morphology were confirmed with nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray powder diffraction and scanning electron microscope. The CO2-sensitivity was demonstrated by monitoring the pH, surface Zeta potential and dispersed appearance under stimulus of CO2. Furthermore, the modified cellulose fibers were packed into a syringe to construct a smart separation column that reversibly captured and released anionic dyes and proteins from water under gas stimulus. Comparing with traditional pH or temperature responsive materials, the CO2-responsive cellulose fibers take the advantages on energy-saving, good reversibility and moderate running conditions, thus might find applications in smart separations, clinical diagnose and therapies.