Competitive cation−π interactions between small cations and polycations with phenyl groups in poly(cation−π) hydrogels

Facile tuning of hydrogel properties by manipulating cationic-aromatic monomer sequences

“…The high degree of swelling of polyelectrolyte hydrogels in water is dominated by the osmotic effect of mobile countions. When the salt concentration approached the polyion concentration, the ionic osmotic effect of the polyelectrolyte was suppressed, resulting in shrinkage of the hydrogel [19,20]. P(cation-co-π) hydrogels have a much lower degree of swelling in pure water and salt solutions, which indicates that the hydrophobic aggregate structure has a strong ability to restrain the swelling of cationic-rich segments.…”

Stimuli responsive dynamic transformations in supramolecular gels

“…302,303 Although rare, cation-p and anion-p interactions are also found in gels. 304,305 Chemical analyte responsive dosimetric gelators are another topic of interest in recent years. [306][307][308] Generally, the binding sites are connected to some associating units on the gelator structure that assist self-assembly involving non-covalent interactions.…”

Quantitative determination of cation–π interactions between metal ions and aromatic groups in aqueous media by a hydrogel Donnan potential method

“…When small cations bind to aromatic groups on a hydrogel network, the same number of oppositely charged small ions (counterions) is localized inside the network by the requirement of electroneutrality. 26 This Donnan effect of ion binding has been considered recently. For example, a Donnan model has been proposed to predict metal binding onto bacterial surfaces.…”

“…By measuring the Donnan potential of the hydrogel, the binding ratio of metal ions to aromatic groups can be quantitatively determined. 26 In principle, the Donnan potential of the hydrogel relative to the surrounding salt solution can be measured by their electric potential difference using two electrodes: one is in the hydrogel and the other is in the salt solution. However, accurately measuring the Donnan potential of hydrogels, especially the polyelectrolyte hydrogels, is a challenge because it is difficult to make a good contact of the electrode to the hydrogels.…”