Abstract
An abstract was not provided in the original work, so a preliminary abstract has been prepared as follows. Of the various topics discussed, a few are briefly mentioned below. A focus on biomimetic water channels concerned the formation of G4 quartet hydrogels. It was found that these hydrogels can form with several different monovalent cations (Li+, Na+, K+, Rb+, and NH4+), but not well with Cs+. The cations are separated from each other in the central channel by about 3.5 Angstroms. The location of anions in G4-potassium complexes or G4 complexes with any cations was also discussed, since the presence of anions affects column stack formation and ionic conductivity. The issue of selectivity for use in environmental remediation was briefly addressed. I4 quartet channels were also an important topic of discussion.