Aligned electrospun sulfonated polyetheretherketone nanofiber based proton exchange membranes for fuel cell applications

Abstract

In this study, electrospinning of sulfonated poly(ether ether ketone) (SPEEK) at different degrees of sulfonation (DS) was investigated. The polymer solution concentration of 22 wt% was obtained to collect smooth fiber in nanoscale range of 112 to 131 nm at various conditions. SEM observations of SPEEK nanofibers showed the decrease of diameter with increasing DS from 74% to 81%, mainly due to the increase of electrical conductivity of polymer solution at higher DS. The increase of collecting speed from 20 to 305 m/min decreased the diameter of nanofibers slightly and improved their alignment. The presence of SO3H groups in collected nanofibers was demonstrated with FT‐IR analysis. WAXD patterns of SPEEK nanofibers indicated featureless amorphous peak with no crystalline regions that was broaden at higher DS and aligned nanofibers. The electrochemical impedance spectroscopy of SPEEK nanofibers showed the through‐plane proton conductivity of fully hydrated nanofibrous membranes measured at room temperature were improved with DS. The proton conductivity of randomly oriented and aligned nanofibers were measured from 0.0098 to 0.0722 S/cm and from 0.0592 to 0.0907 S/cm, respectively. Aligned nanofibers exhibited more proton conductivity than randomly collected nanofibers. POLYM. ENG. SCI., 57:789–796, 2017. © 2016 Society of Plastics Engineers

Nanofibers as novel platform for high‐functional ion exchangers

“…In addition, Sadrjahani et al . found that the proton conductivity of the electrospun nanofibrous membranes of sulfonated poly(ether ether ketone) increased with the degree of sulfonation . In other words, the ionic conductivity can be improved by increasing the charge groups.…”

Modeling and optimization of sulfonated poly (ether ether ketone) nanofibrous proton exchange membranes with response surface methodology

“…PEEK with 1 g weight was dispersed in 10 mL of concentrated sulfuric acid at 50°C under vigorous stirring for sulfonation. The reaction was carried out with the sulfuric medium for 6 hours to obtain the sulfonated PEEK (SPEEK) with the degree of sulfonation of 74% as reported in previous work . Afterward the solution of SPEEK was precipitated in an excess of cold water.…”

Modeling and optimization of waterproof‐breathable thermo‐regulating core‐shell nanofiber/net structured membrane for protective clothing applications

“…In fact, the major objective is to optimize these responses . RSM has been applied successfully for optimization in the field of membrane, such as optimizing the performance of polyvinylidene fluoride (PVDF) membrane for immunoblotting application , chitosan/hydroxyapatite composite membrane for the removal of metal ions from aqueous solutions , sulfonated poly (ether ether ketone) membrane for proton exchanging , and PU/poly (2‐acryloylamido‐2‐methylpropanesulfonic acid)‐graphene oxide P(AMPS‐GO) hybrid membrane for applying as a layer in protective clothing . Researches have selected the factor spaces, Box–Behnken design (BBD), and central composite design (CCD) as experimental design techniques in this manner , but most of them have chosen CCD .…”

“…As mentioned, some researchers have tried to model and optimize conventional fibrous structured membranes with an aim of increasing their performance efficiency . In present study, our interests focused on modeling and optimizing the waterproof‐breathable membrane with the core–shell nanofiber/net structure and thermal regulating property, for the first time.…”