Water-stable membranes were fabricated from carboxymethyl cellulose (CMC) acting as anionic adsorbent and cellulose nanofibrils (CNFs) as strengthening filler by solvent- and freeze-casting processes, both supported with simultaneous citric acid (CA) mediated cross-linking. Spectroscopic and potentiometric titration techniques were applied to evaluate the efficacy of the cross-linking as well as to quantify the processing-dependant surface charge. In addition, the CMC/CNF assembling and membrane porosity were identified microscopically. The membrane’s dye adsorption capacity and kinetic were evaluated for filtration performance at optimal pH. The resulting, freeze-casted membranes demonstrate anisotropic to isotropic and highly () 90%) porous structures with gradient pore sizes (from few nm up to 200 µm range). This provides relatively high and stable flux rates (150-190 kL/m2 h MPa) with ~100% dye adsorption, fast dynamic (8.536-5.446 kg/g min) and capacity (1828-1398 g/kg), which highlight their potential in dead-end filtration technologies. The similar dye adsorption capacity was assessed for denser and nano-porous (( 50 nm) solvent-casted membranes, however, with much lower and time-declining flux rates (100-10 L/m2 h MPa), demonstrating their potential usage in spiral wound-cross-flow modules. Both types of membranes showed high dye removal capacity (? 90%) even after 4th (solvent-casted) and 50th (freeze-casted) reusing cycle, present a high-value alternative to other bio-nano-absorbents. In addition, the membrane’s lysozyme (Lys) binding capacity and transport was evaluated by chromatographic mode. Due to very open structure, high permeability and lysozyme recovery above 95% was achieved, resulting to a binding capacity of 0.3-0.7 mg Lys per mg of dry membrane which is a promising results for biochromatography.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 22788886