Effect of lignin–cellulose nanofibrils on the hydrophilicity and mechanical properties of polyethersulfone ultrafiltration membranes

Abstract

In the present research, novel polyethersulfone (PES)/lignin–cellulose nanofibril (LCN) blend ultrafiltration membranes with high hydrophilicity and noticeable mechanical properties were prepared via immersion precipitation method. LCN was employed to improve the hydrophilicity and mechanical properties of pure PES ultrafiltration membranes. Transmission electron microscopy and Fourier transform infrared spectroscopy (FTIR) were used to characterize the structure of the LCN. The performance of blend ultrafiltration membranes were characterized in terms of FTIR, thermogravimetric analysis, scanning electron microscopy, pure water flux (PWF), bovine serum albumin retention, water contact angle, surface energy, and mechanical properties. With the increase in content of LCN from 0 wt% to 1.2 wt%, the PWF improved from 322.8 L m⁻² h⁻¹ to 692.3 L m⁻² h⁻¹ and the tensile strength increased from 4.8 MPa to 7.2 MPa. It was revealed that the addition of LCN could improve the hydrophilicity and mechanical properties of pure PES ultrafiltration membrane.