Self-assembled proton conduction networks consisting of SPEEK, NH2-POSS, and IL with enhanced proton conduction and decreased IL loss

• Published in: Polymer (Guilford) Vol. 254; p. 125011
• Main Authors: Guan, Zhifu, Jin, Yiqi, Shi, Sha, Jin, Biyao, Zhang, Meishan, Zhao, Lianhua
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 21.07.2022
• Subjects: Anhydrous proton exchange membrane; Imidazole type ionic liquids; Molecular-level hybridization; NH2-POSS nanoparticle; Sulfonated polyether ether ketone; Molecular-level hybridization; NH2-POSS nanoparticle; Sulfonated polyether ether ketone; Anhydrous proton exchange membrane; Imidazole type ionic liquids
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/j.polymer.2022.125011

To enhance the conductivity of sulfonated polyether ether ketone (SPEEK, SP) membrane and avoid the loss of ionic liquid (IL), using aminopropyloligosisiloxane (NH2-POSS) as molecular hybrid filler, a self-assembled medium temperature and non-humidified SP/IL/NH2-POSS hybrid membrane was prepared. NH2-POSS can be assembled into the hydrophilic domain ion phase of SPEEK. In which, –NH2 of NH2-POSS and –SO3H of SPEEK formed acid-base pairs at the interface which were conducive to the construction of proton transport channel. In addition, NH2-POSS enriched IL in the hydrophilic domain, which retained IL while synergistically increased the conductivity. The results showed that the IL loss rate of SP/IL/NH2-POSS-2 membrane was 46.9 wt%, which was about 55.8% of SP/IL membrane; the conductivity of SP/IL/NH2-POSS-2 membrane at 200 °C without humidification was 5.51 mS·cm−1, which was about 4 times that of SP/IL membrane. [Display omitted] •Molecular-level network SP/IL/NH2-POSS proton exchange membrane was prepared.•-NH2 and –SO3H constructed ordered proton transport channels via acid-base pairs.•IL is enriched on NH2-POSS and SPEEK interface through hydrogen bonding.•Acid-base pairs and IL-rich layer synergistically increase proton conductivity.