Effect of embedded activated carbon nanoparticles on the performance of polydimethylsiloxane (PDMS) membrane for pervaporation separation of butanol

BACKGROUND The pervaporation separation method is considered to be a promising technique for biobutanol recovery from fermentation broths. In this work, activated carbon nanoparticles were embedded in polydimethylsiloxane (PDMS) membranes to improve the pervaporation performance. RESULTS Adding 6 wt% nano-additives in PDMS membranes increased the flux and separation factor by 42.6% and 51.9%, respectively, compared with neat membranes at 37°C. Enhanced performance is due to: 1 the presence of additional sorption sites within the membrane with a high affinity for butanol; and 2 the porous structure of the nanofillers generate new pathways for facilitated mass transport through the membrane. The effect of the operating temperature and particle concentration on membrane performance was investigated. Membrane performance improved with an increase in the operating temperature. Higher temperature resulted in increased free volume in the PDMS chains leading to higher diffusion of butanol. Mechanical tensile tests showed that nanocomposite membranes have better mechanical stability in comparison with neat PDMS membranes with the best performance observed at 6 wt% of the nano-additives. CONCLUSION The presence of activated carbon nanoparticles in the matrix of PDMS membranes leading to higher flux and separation factor can be beneficial for pervaporation separation of butanol from fermentation broths. © 2017 Society of Chemical Industry