Linking interfacial energies with proton conductivity in sulfonated poly (ether ether ketone) nanocomposite

The effect of polydopamine coated multi‐walled carbon nanotube on the wettability of sulfonated poly(ether ether ketone) nanocomposite as a proton exchange membrane

“…12,52,53 Our previous study reveals that PDA modification of CNT causes the interfacial energy between the SPEEK and nanotubes increases from 5.9 mJ/m 2 to 17.4 mJ/m 2 in SPEEK-PCNT interface. 40 In other words, the higher interfacial energy results in lower adhesion strength between the PCNT and SPEEK, and these results confirm the claim of proton transfer through the interface region of CNTs and polymer matrix. 54,55 It is worth noting that the chemical structure of nanofiller is a determinative parameter in the proposed proton conduction mechanism.…”

“…8,50,51 According to our previous study, the optimized content of PCNT to achieve the maximum value of proton conductivity is 3.5 wt%. 40 At this content of PCNTs, the proton conduction reaches 0.064 S/cm. Table 6 shows the proton conductivity of SPEEK based nanocomposite as a PEM which have been reported in the literature and it reveals that the achieved value of proton conductivity in the present study is appropriate.…”

“…Previous studies have reported, as a result of the PDA polymerization in the Tris-HCl buffer, the decoration of PDA polymer on the surface of CNTs is realized through the π-π stacking interaction and π electron. 39,40 Due to the high aspect ratio and inert surface of CNTs, their entanglement tendency is high. This trait leads to the poor dispersibility of CNTs and hinders the wide application.…”

“…On the other hand, regard to the our previous study; since the SFE value of PDA-modified CNTs is greater than the unmodified ones, so the total SFE of the nanocomposite could be higher than the plain one. 40 Our previous study 40 showed that the total SFE of CNT is and 23.6 mJ/m 2 the polar and disperse components are 17.4 mJ/m 2 and 6.2 mJ/m 2 , By PDA coating of nanofiller, the total SFE of PCNTs was estimated to be 29.4 mJ/m 2 , with the polar part of 28.1 mJ/m 2 and disperse part of 1.3 mJ/m 2 . The polymer surface will be governed by a multitude of factors, including: (a) polymer characteristic related factors, like polymer chemistry, polymer composition and structure, and molar mass and dispersity.…”

Water-Mediated Proton Conduction in Metal–Organic Frameworks with High Water Stability Constructed by a Terpyridine Tricarboxylate Ligand

“…The adsorption peaks of 1373 and 1273 cm –1 , respectively, represent asymmetric vibration and symmetric stretching vibration of SO bonds of 1 . − In addition, the peaks centered at 989, 1030, 1110, and 1173 cm –1 can identify the vibration modes of the bridging sulfate groups . What makes sense is that introducing acid sites such as SO 4 2– and −COOH into the structure can exert a unique advantage because they could provide a medium concentration of acidic proton carriers inside MOFs and dynamically abundant hydrogen bonds for proton conduction. − As denoted in Figure b, 1D hydrophilic channels formed by the acid site, μ 3 -SO 4 2– , and H 2 O molecules along the b -axis seem to be the main body of proton conduction. Furthermore, the noncoordination −COOH groups and H 2 O molecules (O10, O13) formed small closed hydrogen bond rings hanging in the 1D water belt.…”