Graphene oxide crosslinked poly(phenylene oxide) nanocomposite as high-performance anion-conducting membrane

A Composite Anion Conducting Membrane Based on Quaternized Cellulose and Poly(Phenylene Oxide) for Alkaline Fuel Cell Applications

“…Similarly, DG-Cel showed the stretching band corresponding to the DG at 1610 cm −1 for the C=N stretching, confirming the quaternization reaction [ 54 ]. As shown in Figure 1 c, the characteristics of the stretching band for PPO were observed at 2923 (aromatic C–H stretching), 1469, and 1600 (aromatic ring stretching), and 1182 cm −1 (aromatic C–O stretching) [ 25 ]. The bromination of PPO was confirmed by the C-Br stretching band at 500 cm −1 in the FTIR spectra of bPPO ( Figure 1 c) [ 51 ].…”

“…The structure of the membranes was further characterized by TEM as shown in Figure 3 . The dark regions in the TEM image correspond to the hydrophilic domain, whereas the bright region represents the hydrophobic part [ 25 , 58 , 59 ]. The distribution of the darker regions in qPPO/DG-Cel7 ( Figure 3 b) is more distinct and evenly spread than in qPPO/D-Cel7 ( Figure 3 a), demonstrating better phase segregation in the former.…”

“…The TEM samples were prepared by ultramicrotomy (UMT, PT PC Ultramicrotome and Photographic, RMC, New York City, NY, USA) immersed in Na 2 WO 4 (1 mol L −1 ) solution at 30 °C for 48 h. The samples were then washed several times with HPLC water and dried in a vacuum oven at 30 °C for 24 h. Thermogravimetric analyzer (TGA, TA Instruments SDT Q600, Philadelphia, PA, USA) was used to investigate the thermal stability of the membranes. The equations used in a previous work [ 25 ] were employed to calculate the IEC, water uptake, and swelling ratio of the membranes.…”

“…Humidified nitrogen gas was introduced into the unit cell apparatus to prevent CO 2 contamination and desertification of the membranes. The ionic conductivity was calculated by the equations below [ 25 ]: where is the ionic conductivity (S cm −1 ), d is the distance between the two electrodes (cm), R is the resistance ( ), and A is the surface area (cm 2 ) of the membranes.…”

“…Recently, polyphenylene oxide (PPO) has attracted considerable interest as AEM material in AEMFCs owing to its excellent thermal property, good mechanical attributes, and chemical stability [ 25 , 26 ]. PPO has been widely applied in various fields such as high-pressure hydraulic fracturing [ 27 , 28 ], porous media [ 29 , 30 ], and pervaporation membrane [ 31 , 32 ].…”