Finite element analysis of fibreglass and carbon fabrics reinforced polyethersulfone membranes

Abstract

Despite promising applications of polyethersulfone (PES) membranes in several advanced technologies (gas separation, clean energy, water treatment, etc.), their weak mechanical strength (2.54 MPa) remains the main obstacle for upgrading and is mainly responsible for its shorter service time, especially in high pressure applications. In this context, this research aims to improve the mechanical properties of the PES membrane by supporting it with a substrate made of woven fabric with high mechanical strength and porosity to ensure that the pores of the membrane are not clogged, thus maintaining their permeability. The PES composite membranes were prepared by combining different types of fabrics (glass fibre “GF” and carbon fibre “CF”) using the phase-inversion method. The cross-section microstructure, surface morphology, fabric cohesion with a PES thin layer, roughness, and specific surface area and pore size distribution were observed using a scanning electron microscope, atomic force microscopy, and Brunauer–Emmett–Teller. Meanwhile, the mechanical, chemical, and thermal properties of composite membranes were monitored using tensile test, X-ray Powder Diffraction, Fourier Transform Infrared Spectroscopy, and Thermal Gravimetric Analysis. Finally, the mechanical measurements of the prepared membranes and their crack propagation were modelled as a sandwich-structured composite using the finite element method (FEM). The results revealed that the support layer can increase the strength of membranes up to 207 MPa (GF/PES) and 245 MPa (CF/PES), while maintaining its porous structure in the range of 64–67 nm. Also, the thermal stability of the membranes increased up to 64–67 wt% compared with the neat PES membrane. Besides, both membranes exhibited high roughness in the range of 363–939 nm. Meanwhile, the FEM succeeded in predicating and simulating the load-deformation curves for both membranes with a match of > 98%. Based on these results, woven fabrics can be used as a promising support layer to improve the mechanical performance and service life of PES membranes.