Effects of the Particle Size and Concentration of Polytetrafluoroethylene (Ptfe) on the Development of Hydrophobic/Hydrophilic Dual-Layer Membranes for Membrane Distillation

This study investigates the impact of particle size and concentration of polytetrafluoroethylene (PTFE) on the development of hydrophobic/hydrophilic dual-layer membranes for direct contact membrane distillation (DCMD). The objective of this study was to evaluate the effect of PTFE particle size (0.5 μm, 1 μm, and 6 μm) and concentration (0wt%, 2wt%, 4wt%, and 6wt%) on membrane properties and performance using a combination of scanning electron microscopy (SEM), liquid entry pressure (LEP), contact angle, atomic force microscopy (AFM), mercury intrusion porosimetry (MIP), permeate flux, nitrogen gas permeation, and salt rejection analyses. The DCMD experiment was conducted under the feed temperature of 70˚ C and 8000 ppm salt concentration. The results show that the optimal particle size for PTFE in the membrane is 0.5 μm, and the best concentration is 6wt%. These findings demonstrate the importance of considering particle size and concentration in the design of these membranes and have significant implications for MD applications. The results indicate that the PES-PTFE dual-layer membrane with 0.5 μm PTFE particle size and 6wt% concentration has the highest performance in terms of membrane properties such as a highest permeate flux of 11 kg.m2/h, and outstanding salt rejection rate of 99.8%, and nitrogen gas flux of 11.56 L/m2.h. This study provides insight into optimizing membrane design for DCMD applications and has the potential to impact the development of more efficient and effective membrane systems for water and energy management.