Effective electroosmotic transport of water in an intrinsically microporous polyamine (PIM-EA-TB)

Electrochemistry Communications

Frank Marken¹  Mariolino Carta²  Zhongkai Li³  Neil B. McKeown⁴  Richard Malpass-Evans⁴  Klaus Mathwig⁵  John P. Lowe⁶ 

[1] Chemical Characterisation Facility MC2, Bath BA2 7AY, UK;Department of Chemistry, Swansea University, College of Science, Grove Building, Singleton Park, Swansea SA2 8PP, UK;Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK;EaStCHEM, School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh, Scotland EH9 3JF, UK;Stichting imec Nederland within OnePlanet Research Center, Bronland 10, 6708 WH Wageningen, The Netherlands;;University of Bath, Materials &

关键词: Microporosity;    Voltammetry;    Electroosmosis;    Desalination;    Solar water harvesting;   

DOI  :  

来源: DOAJ

【 摘 要 】

Tertiary-amine-based Polymers of Intrinsic Microporosity (PIMs) provide a class of highly porous molecularly rigid materials for the electrochemical transport of both ionic and neutral species. Here, the transport of water molecules together with chloride anions (i.e. the electroosmotic drag coefficient) is studied for the intrinsically microporous polyamine PIM-EA-TB immersed in aqueous 0.01 M NaCl (i) when protonated for pH < 4 or (ii) when not protonated for pH > 4. Preliminary data suggest that in both cases a high electroosmotic drag coefficient is observed based on direct H2O transport into a D2O-filled compartment (quantified by 1H-NMR). For PIM-EA-TB there is a strong pH dependence with a higher electroosmotic drag coefficient in less acidic solutions (going from approx. 400 H2O per anion at pH 3 to approx. 4000 H2O per anion at pH 7), although the underlying absolute rate of water transport at a fixed voltage of −1 V appears to be essentially pH independent. Water transport through the PIM-EA-TB microchannels is rationalised based on the relative populations of chloride anions and of water in the micropores (essentially a ‘piston’ mechanism).

【 授权许可】

Unknown