Facile electrospray fabrication of ultralow biofouling cellulose acetate desalination membrane with nanocellulose/UiO66-NH2 fillers

Abstract

The inherently high porosity, hydrophilicity, and large surface area of the octahedral UiO66-NH2 nanocrystals were exploited in synergy with cellulose nanocrystals (CNCs) as electrospray coating nanocomposites onto the cellulose acetate (CA) desalination membranes. Optimal loadings of both nanoparticles (0.05% w/v each) enabled the partial embedment of the defective metal-organic framework (MOF) crystals in the dense CA layer, successfully facilitating a faster, low-tortuosity water transport pathway through the active layer. With just one electrospray scan, the CNC/UiO66-NH2-coated CA membrane achieved an almost doubled the water permeability coefficient of 0.24 L m−2 h−1 bar−1 while maintaining a retention efficiency of over 94% in brackish water desalination. Moreover, the electrospray-coated membrane demonstrated healthier flux recovery from continuous E. coli cross-flow filtration exposure, exhibiting great resistance to biofouling. Overall, the CNC/UiO66-NH2-coated CA membrane outperforms many CA-based desalination membranes reported in the literature in terms of water/salt permselectivity and anti-fouling capabilities.