Fabrication of a high-performance polyurethane pervaporation membrane via surface grafting of silane coupling agent

Membrane separation technology has the advantages of energy saving, eco-friendly, and high separation efficiency, and it is a promising separation technology in the field of sulfide removal in gasoline. In this work, to improve the desulfurization performance of polyurethane (PU) membrane, hexadecyl trimethoxy silane (HDTMS) was applied to functionalize the PU surface via a facile and efficient surface grafting method. This surface grafting method has the advantages of simple operation, economy, no need for high temperature and highly toxic solvents, and could effectively improve membrane separation performance. The morphology of the fabricated membrane was systematically characterized by various means. After HDTMS surface grafting, the non-penetrating gully structure appeared on the surface of the membrane. This non-penetrating gully structure increased the effective membrane area while reducing mass transfer resistance; therefore, it had an important impact on the pervaporation desulfurization performance. By optimizing the hydrolysis time, the concentration, and the grafting time of HTDMS, the flux of the membrane achieved 2.92 kg center dot m(-2)center dot h(-1), which increases by 207% in comparison with the nascent PU membrane, and the corresponding enrichment factor still maintained an acceptable value of 6. In addition, after a 100-h long-term test, the performance of the PU-HDTMS membrane was stable, which indicated a superior application prospect.

Automated summary

Membrane separation technology is an energy-saving, eco-friendly, and highly efficient separation technology, which can be applied in sulfide removal from gasoline. In this study, a facile and efficient surface grafting method was used to functionalize polyurethane (PU) membrane with hexadecyl trimethoxy silane (HDTMS), resulting in improved separation performance. Optimized grafting conditions led to significant enhancements in membrane flux and enrichment factor, and the PU-HDTMS membrane showed stable performance after long-term testing.