An in-depth analysis of Pebax-1657/GO-silica/PEI thin film nano-composite membranes for gas dehydration

Abstract

This research aimed to study the effectiveness of blending Pebax-1657 polymer with GO/SiO₂ nanoparticles in developing TFN membranes for N₂ gas dehydration. Different concentrations of nanoparticles (0 %, 0.5 %, and 1 %) were incorporated using dip coating. The nanocomposites were analyzed for their chemical structure, morphology, topology, and thermal stability using FTIR, SEM, CA, AFM, and TGA. The results showed that the samples had good thermal stability and a highly hydrophilic surface. The MP0.5–0.5 membrane with 0.5 % GO/SiO₂ nanoparticles demonstrated improved performance in water vapor and N₂ permeance at 2 × 10⁵ to 6 × 10⁵ Pa pressure and 70 % relative humidity. The addition of 0.5 % GO nanoparticles to the sample further enhanced H₂O and N₂ permeance and separation factor. However, in the case of the MP0.5–0.5 membrane, a different scenario unfolds, showcasing a synergistic effect and the ideal morphology was observed. The water vapor and nitrogen permeance of the MP0.5–0.5 membrane, under 2 × 10⁵ to 6 × 10⁵ Pa pressure and 70 % humidity, reaches from GPU 158 and GPU 0.23 (for the neat mebrane) to GPU 969 and GPU 31, respectively. The H₂O/N₂ separation factor was recorded as 679.It was observed that the relative humidity of the gas decreased from approximately 70 % to about 1.2 % during the membrane step, indicating the high efficiency of the membrane. The investigation concluded that the TFN membranes' dehydration characteristics are influenced by various factors, including morphology, plasticization, and hydrophilic properties. Changes in the feed gas flow rate also affected separation factor and nitrogen permeance. The rise in sweep gas flow had a notable impact on enhancing the membrane's separation factor by decreasing the transmembrane concentration gradient. Consequently, a trade-off emerges between water vapor flux and separation factor when employing the sweep gas stream. These discoveries are highly valuable in industrial settings, as they offer a more profound understanding of the topic.