Proton exchange membrane fuel cell

Organic chemistry

Polymer chemistry

Membrane

Composite number

Engineering

Conductivity

Catalysis

Physical chemistry

Composite material

Chemistry

Phosphotungstic acid

Materials science

Halloysite

Nanotube

Chemical engineering

Carbon nanotube

Biochemistry

Polymer Testing

Anchoring phosphotungstic acid (HPW) on insoluble inorganic fillers is a facile and effective approach to suppress its leakage in the proton exchange membrane. In this work, we introduced β-cyclodextrin (β-CD) on halloysite nanotubes (HNTs) with the aid of polydopamine coating to prepare water-insoluble β-CD-DHNTs, which was dispersed in the SPEEK matrix to anchor HPW. Both HPW and β-CD-DHNTs are well dispersed in the SPEEK matrix because of the hydrogen bonding complexation between [PW12O40]3- and β-CD. For the SPEEK/β-CD-DHNTs/HPW composite membranes, the proton conductivity increased with the increase of HPW content, reaching the maximum of ~120% increase relative to that of the SPEEK membrane. The HPW immobilized by the β-CD and polydopamine on the nanotubes could provide more active sites, resulting in the construction of more continuous proton transfer pathways. Therefore, as compared to the SPEEK membrane, lower activation energy for the proton transport was observed for the composite membrane, which also exhibited stable proton conductivity during the water immersion test for 30 days.

Composite membranes anchoring phosphotungstic acid by β-cyclodextrins modified halloysite nanotubes