Novel pH responsive calix[8]arene hydrogelators: self-organization processes at a nanometric scale.

Water soluble amphiphilic calix[8]arenes have been found to form pH-responsive and reversible supramolecular hydrogels at sub-millimolar concentration. Depending on their upper rim functionalization, pH variations trigger hydrogelation under basic or acidic conditions. Studies on self-organization processes by atomic force microscopy (AFM) measurements on differently charged surfaces are reported.