Chemical physics insight of PPy-based modified ion exchange membranes: A fundamental approach

Microstructural description of ion exchange membranes: The effect of PPy-based modification

“…Modified IEMs were done following the same procedure as described in our previous work [19]. The strategy consists of soaking the IEM in an acidic Py solution (0.1 M solution) and subsequently soaked to an oxidizing solution (FeCl 3 0.5 M solution, in this case) to carry out the polymerization during a certain time (6 and 18 min, respectively).…”

“…Finally, a linear regression was built with different standard solutions (basic-phenolphthalein and nitrate ion solutions for CEMs and AEMs, respectively) were used to determine the number of displaced ions by using a UV-Vis spectrophotometer. Further details of the procedure can be found in our previously work [19]. IEC was calculated using Eq.…”

“…In this work, we have deeply analysed four IEMs (two cationic and two anionic) to foresee their potential application in RFBs and inquire about new pathways to enhance their features to address a suitable material for these kinds of devices. In our previous work [19], we proposed a membrane modification to prevent or decrease the crossover phenomena which is detrimental for the battery capacity decay and consequently, the energy efficiency. Such modification consisted of a chemical in situ polymerization inside the micropores and interstices by soaking the membrane in pyrrole (Py) solution and subsequently soaked in FeCl 3 solution during a certain time.…”

Is It Possible to Prepare a “Super” Anion-Exchange Membrane by a Polypyrrole-Based Modification?

“…In order to improve the membrane properties, the idea of clogging the membrane’s non-selective macropores with a homogeneous microporous ion-exchange material was realized in some studies [ 24 , 35 , 37 , 38 ]. This idea is based on the fact that relatively large (macro)pores are the pathway for coions through the membrane [ 35 , 39 , 40 ].…”

“…The literature shows that PPy-based modification is mainly used to obtain monovalent-ion-selective membranes [ 41 , 42 ]. As far as we know, only the paper of Salmeron-Sanchez et al [ 37 , 38 ] on PPy-based modification of IEMs was aimed at improving other membrane properties, namely, membrane conductivity, and this task was successfully solved in relatively dilute NaCl solutions (up to 0.04 M). Note that the authors used the microheterogeneous model (MHM) [ 43 ] to interpret their results.…”