Processing-structure-property correlations of polyethersulfone/perfluorosulfonic acid nanofibers fabricated via electrospinning from polymer-nanoparticle suspensions

Polyethersulfone (PES)/perfluorosulfonic acid (PFSA) nanofiber membranes were successfully fabricated via electrospinning method from polymer solutions containing dispersed calcium carbonate (CaCO(3)) nanoparticles. ATR-FTIR spectra indicated that the nanoparticles mainly existed on the external surface of the nanofibers and could be removed completely by acid treatment. Surface roughness of both the nanofibers and the nanofiber membranes increased with the CaCO(3) loading. Although FTIR spectra showed no special interaction between sulfonic acid (-SO(3)) groups and CaCO(3) nanoparticles, XPS measurement demonstrated that the content of -SO(3) groups on external surface of the acid-treated nanofibers was enhanced by increasing CaCO(3) loading in solution. Besides, the acid-treated nanofiber membranes were performed in esterification reactions, and exhibited acceptable catalytic performance due to the activity of -SO(3)H groups on the nanofiber surface. More importantly, this type of membrane was very easy to separate and recover, which made it a potential substitution for traditional liquid acid catalysts.