Ceramic membrane with protein-resistant surface via dopamine/diglycolamine co-deposition

Protein separation and purification is important in biotechnology and food processing industries. Ceramic membranes have shown great potentials for this task. But membrane fouling remains a barrier to their widespread application due to the irreversible adsorption of protein onto the membrane. In this work, one-step co-deposition of dopamine (DA) and diglycolamine (DGA) was conducted on the ceramic membranes for fabricating protein-resistant surfaces. CuSO4/H2O2 was used as a trigger to shorten the deposition time and to improve the deposition efficiency. The effect of DA/DGA mass ratio on the membrane structures and properties was studied by FESEM, FTIR, XPS and contact angle measurements. The results indicate that the optimal DA/DGA mass ratio in the co-deposition solution is 1:4. The modified membranes show improved hydrophilicity and negatively charged property. In dynamic protein filtration, these ceramic membranes exhibit a higher permeate flux, a higher water flux recovery, and a lower water flux reduction compared to the original membrane. Moreover, the antifouling property of the modified membrane is preserved after the membranes are treated with high speed water scouring. As a result, this one-step co-deposition method is a simple and effective way to prepare durable fouling-resistant ceramic membranes for protein removal.