Ion and solvent transfers accompanying redox switching of polypyrrole films immersed in divalent anion solutions

Polymer dynamics in thin p-type conducting films investigated by ac-electrogravimetry. Kinetics aspects on anion exclusion, free solvent transfer, and conformational changes in poly(o-toluidine)

“…In a rigid film, kinetics of free H 2 O transfer are governed by kinetics of anion transfer to satisfy volume constraints ( Figure 1) [10]. Consequently, A -= H 2 O and…”

“…Often, the amount of free solvent molecules (not structural) inside a polymeric matrix is a function of the oxidation state of the polymer to satisfy osmotic and volume constraints [10]. The insertion of ionic molecules to balance the charge of the oxidized film involves the displacement of inner solvent molecules.…”

“…This aspect is taken into account either qualitatively or quantitatively but the studies are commonly restricted to overall electrochemical process. Specially, Hillman and coworkers have extensively studied the mobile species transfer processes with the intention of achieving a deeper understanding on the redox dynamics of ICPs (spatial distributions, viscoelasticity, solvent effect, mechanisms) [5][6][7][8][9][10].…”

A Facile Potential-Induced In-Situ Ion Removal Trick: Fabrication of High-Selective Ion-Imprinted Film for Trivalent Yttrium Ion Separation

“…309 One can see that there are no significant differences in the mass change of the composite film water molecule transfers must be involved in the redox process of the conducting polymer films. [24] When Y 3+ ions is absorbed into the Y 3+ -FCN/PPy composite film to balance the 339 charge of the reduced film, the water molecules inside the polymeric matrix will be expelled 340 out from the film owing to the volume constraints. [24,30] The greater the number of Y 3+ ions 341 adsorbed into the composited film is, the more obvious effect of volume constraints will be.…”

“…Furthermore, an 284 obvious upward drift in mass change of composite film can be observed with the increase of 285 the number of potential switching cycle. During the ESIX process, the uptake and release of 286the ions is always accompanied by the solvent ("free" water molecules) transfer [24,. 40] 287 Therefore, the upward drift in mass change of composite film could be attributed to the part of 288 free water molecules retained in the polymer because of the hydrophilicity of PPy[40].…”