Enhanced desulfurization performance of PDMS membranes by incorporating silver decorated dopamine nanoparticles

Abstract

Dopamine–silver (DAAg) nanoparticles were synthesized in aqueous solution via bioinspired adhesion and redox reaction, and they were then incorporated into poly (dimethyl siloxane) (PDMS) matrix to prepare PDMS–DAAg hybrid membranes for pervaporative desulfurization of model gasoline. The loading content of Ag(I) in DAAg nanoparticles could reach as high as 54.03 wt%. The polymer chain flexibility and membrane swelling properties were mediated by DAAg nanoparticles. The hybrid membrane with 5.0 wt% of DAAg nanoparticles displayed an optimum separation performance with permeation flux of 8.22 kg m⁻² h⁻¹ (3-fold higher than that of PDMS control membrane) and enrichment factor of 5.03 (50% higher than that of PDMS control membrane). The enhancement of separation performance was mainly due to the facilitated transport of thiophene by reversible interaction between Ag(I) and thiophene molecules, and the moderate fractional free volume tuned by DAAg nanoparticles. Moreover, effects of operation parameters such as temperature, thiophene concentration in the feed, and feed Reynolds number on the permeation flux and enrichment factor were investigated.