Supramolecular assemblies of polybenzimidazole and aromatic polycarboxylic acids with superior mechanical and H₂/CO₂ separation properties

Abstract

Aromatic polycarboxylic acids complex with imidazoles, forming supramolecular assemblies. Herein, we demonstrate that polybenzimidazole (PBI) can be augmented by aromatic polycarboxylic acids, including phthalic acid (PA), trimesic acid (TMA), and...

Supramolecular Polymer Networks of Ion-Coordinated Polybenzimidazole with Simultaneously Improved H2 Permeability and H2/CO2 Selectivity

“…Table S1). Compared with PBI, the PBI-NiT samples exhibit a new peak of 1550 cm −1 representing the free COO − , 26,30 suggesting the dissociation of NiT in PBI. The PBI exhibits peaks at 1590 cm −1 representing the conjugation between the benzene and imidazole rings, and 1225 cm −1 representing the C−N stretching.…”

“…Therefore, the SPNs are expected to display a decreased free volume size and an increased density of free volume elements. 29,44 We systemically tested the mechanical properties of the SPNs in terms of tensile toughness, yield strain, and stress at four temperatures (30,70,110, and 150 °C) and varying salt contents (cf. Figure S5a−d).…”

“…A lower E P,A of 20 kJ/ mol is obtained for CO 2 permeability because of the greater condensability of CO 2 than that of H 2 . Consequently, the mixed-gas H 2 /CO 2 selectivity increases with increasing temperature (up to 175 °C), similar to PBI 27,30 and different from the PBI cross-linked using weaker bonds such as Hbonds. 26,30 The excellent H even when the water vapor content reaches 1.9 mol %.…”

“…Consequently, the mixed-gas H 2 /CO 2 selectivity increases with increasing temperature (up to 175 °C), similar to PBI 27,30 and different from the PBI cross-linked using weaker bonds such as Hbonds. 26,30 The excellent H even when the water vapor content reaches 1.9 mol %. The stable separation performance further confirms the thermal stability of the film against physical aging and water vapor.…”

“…The molar ratio of the salt to PBI repeating units in the solutions varied from 0.5 to 2 for Pd(TFA) 2 and from 1 to 8 for Ni(TFA) 2 to achieve different doping levels in the films, as shown in Figure 1b. 30 The molar ratio of acetone to the PBI repeating units was kept at 1000. During the doping process, the ions diffuse into the films, and the sorption reaches equilibrium within 48 h, as indicated by the similar values of the doping level after 48 h of doping (cf.…”