Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... New hydrophobic polyether tetraesters substituted with carbon chains at C 8 and C 12 have the ability to transport selectively, but not very efficiently, th K + and NH + 4 ions. ... Cookies are used by this site. To decline or learn more, visit our Cookies page.