In situ synthesis of star copolymers consisting of a polyhedral oligomeric silsesquioxane core and poly(2,5‐benzimidazole) arms for high‐temperature proton exchange membrane fuel cells

Abstract

Star copolymers with good film-forming and mechanical properties were insitu synthesized for fabricating proton exchange membranes. The monomers of 3,4diaminobenzoic acid were first grafted onto glycidyl-polyhedral oligomeric silsesquioxane (G-POSS) cores and then propagated to the poly(2,5-benzimidazole) (ABPBI) chains. The introduction of the star copolymer improves the movement of the ABPBI polymer chains, resulting in a lower internal viscosity and larger free volume that favor increased membrane flatness and absorbilities of water and phosphoric acid molecules, respectively. It was found that the star copolymers with 1.0 wt% of incorporated POSS (ABPBI-1.0POSS) had the best balance of the acid retentivity and film-forming property as well as mechanical properties that are desirable for proton exchange membranes without PA loss operating at high temperatures. The enhanced cell performance characteristics obtained using the ABPBI-1.0POSS-based membranes indicate that star copolymers are promising materials for use in high temperature proton exchange membrane fuel cells.

Molecular Imprinted Poly(2,5-benzimidazole)-Modified VO2–CuWO4 Homotype Heterojunction for Photoelectrochemical Dopamine Sensing

“…Incorporation of the template molecule, DA, into the ABPBI polymer exhibited distinguishing bands around 1435 cm −1 (C−N stretching mode of amine functional group). 35 Additionally, the polymer with DA shows the characteristic bands around 3430 cm −1 , corresponding to the aromatic O−H stretching vibrations. Also, the band at 1535 cm −1 (N−H bending) shifted to 1540 cm −1 due to the interaction with the DA template.…”

“…The in-plane C–H deformations produce a band at 1247 cm –1 . Incorporation of the template molecule, DA, into the ABPBI polymer exhibited distinguishing bands around 1435 cm –1 (C–N stretching mode of amine functional group) . Additionally, the polymer with DA shows the characteristic bands around 3430 cm –1 , corresponding to the aromatic O–H stretching vibrations.…”

“…So, the well depression of the influence of the MIP recognition component on the PEC performance of photoelectric active material is still a challenge . In this work, for the first time, we use poly­(2,5-benzimidazole) (ABPBI) as a synthetic polymer to introduce novel MIP owing to the highest intrinsic proton conductivity, Π-conjugation, highly interactive active sites, and photoactivity. , Besides, it is proven that low bandgap SC nanomaterials with large specific surface areas can be applied as imprinting substrate in PEC sensors. , Moreover, the PEC response and sensitivity of the MIP-PEC sensor could be improved by combining the level matching photoelectrically active polymers with SC . However, the low energy harvesting efficiency (rapid recombination of the charge carriers) of SCs in pristine form still limits their wide PEC applications. , To address these subjects, several strategies are ordinarily utilized to improve the energy harvesting efficiency of SCs such as surface engineering (doping), interface engineering (heterojunctions), and bulk engineering (morphology), which all can boost the charge transfer and create a preferable density of states. − Also, among them, heterojunctions and their subtype, the type-II, have received the most attention and are generally constructed with high-symmetry lattice structures. , The developed type-II heterojunction exhibits ultrafast spatial separation of photogenerated charge carriers, promising charge transfer dynamics, extensive utilization of the visible spectrum, and fast mass transfer. , Type-II heterojunctions can be prepared by combining different p- and n-type SCs such as metal oxides, metal chalcogenides, metal phosphides, carbon-based SCs, metal oxyhalides, metal chalcogenides, and so on.…”

“…34 In this work, for the first time, we use poly(2,5benzimidazole) (ABPBI) as a synthetic polymer to introduce novel MIP owing to the highest intrinsic proton conductivity, Π-conjugation, highly interactive active sites, and photoactivity. 35,36 Besides, it is proven that low bandgap SC nanomaterials with large specific surface areas can be applied as imprinting substrate in PEC sensors. 31,37 Moreover, the PEC response and sensitivity of the MIP-PEC sensor could be improved by combining the level matching photoelectrically active polymers with SC.…”

Highly Stable Membranes of Poly(phenylene sulfide benzimidazole) Cross-Linked with Polyhedral Oligomeric Silsesquioxanes for High-Temperature Proton Transport

“…The higher content of g-POSS in cPPSBi_15 is responsible for an approximately 2 times higher stress at break with respect to the cPPSBi_10 due to the higher number of interconnections between the polymer chains. Additionally, the low molecular weight of the polymer and its high density of cross-linking compared to similar systems 68 negatively affect the tensile strength of the produced membranes. What is encouraging is the behavior of crosslinked membranes in the doped state.…”