Design of sponge-like PES hollow fiber membranes using the environmentally friendly solvent N,N-dimethyl lactamide

Changing the process conditions for the preparation of hollow fiber membranes can result in significant alterations of the structure and performance of the resulting membrane. Consequently, the preparation of membranes with the desired membrane structure using new, environmentally friendly solvents require a large amount of experimental data. The design of experiments (DoE) approach represents a valuable tool for the development of new membranes with high performance through a reduced number of experiments. Additionally, it facilitates the understanding of the correlation between preparation parameters and the resulting membrane structure, performance, and mechanical properties. Given the necessity of reducing the environmental impact of membrane preparation through the replacement of conventional solvents, the design of new membranes using more environmentally friendly solvents is a crucial objective. In this study, the DoE approach was employed to develop macrovoid-free hollow fiber membranes using the less harmful and more environmentally friendly solvent N , N -dimethyl lactamide. Empirical models were established allowing the prediction of membrane structure and mechanical strength. Consequently, the optimal settings of the DoE allowed the preparation of an ultrafiltration membrane that exhibited the desired mechanical strength (6 MPa), retention (cut-off at 100 kDa), permeance (50 LMHB), and homogeneous structure (at least 99 % sponge-like structure).