Functionalized Bentonite clay-sPEEK based composite membranes for direct methanol fuel cells

Sulfonated fullerene in SPEEK matrix and its impact on the membrane electrolyte properties in direct methanol fuel cells

“…The second weight loss from 380 C is attributed to the degradation of sulfonic acid groups attached to the fullerene followed by the decomposition of C 60 cage around 640 °C [34]. It noteworthy that mass loss during the desulfonation process (380-640 C) is observed as 18 % which is equal to the sulfonic acid grafted on the surface of fullerene [23] and is also similar to the degree of sulfonation for fullerene (DS) calculated from CHNS analysis.…”

“…In addition, the presence of more dead end channels in SPEEK limits the proton conductivity affecting the overall fuel cell performance [20]. Many methodologies are explored in the literature to improve the properties of SPEEK as a membrane electrolyte and the important ones include blending of SPEEK with aliphatic polymers, fabrication of composite membranes of SPEEK with inorganic materials as additives (zirconia, clays and zeolites) and also the modification of SPEEK with superacids like heteropolyacids to enhance its proton conductivity [21][22][23][24][25]. These modifications to SPEEK also showed improved methanol permeability characteristics in DMFCs.…”

Hybrid Materials Based on Bentonite Functionalized with Amine Groups via the Hydrolytic Sol-Gel Method

“…9,26,27 As for the spectra of BEN-APTS, BEN-TMPT, and BEN-TMPO (spectra b-d in Figure 2), they display bands between 2929 and 2795 cm -1 , ascribed to CH/NH groups, and at 1567 and 1330 cm -1 , ascribed to amine groups (NH 2 ). The FTIR spectra indicated functionalization of bentonite with the alkoxides.…”

“…BEN gave a smaller interlayer distance than the distance described by Vieira et al 35 (around 11.51 and 15 Å, respectively). Other authors found an interlayer distance of 8 and 9 Å when they used 3-mercaptopropyltrimethoxy silane 27 and pillaring with Al and Co 36 to modify bentonite, respectively. The bentonite source and the functionalizing agent probably accounted for the different regions of the clays, namely interlayer, edge, and surface, evidenced by FTIR and XRD results regarding distance.…”

“…27,33,34 The interlayer distance was calculated by Bragg's law (nλ = 2dsenθ). BEN gave a smaller interlayer distance than the distance described by Vieira et al 35 (around 11.51 and 15 Å, respectively).…”