title: Effect of amide moieties for hydrogelators on gelation property and heating-free pH responsive gel-sol phase transition.
abstract: Two long-chain amidoamine derivatives (C13A2AOH and C17A2AOH) bearing three amide moieties were synthesized and their gelation ability and pH responsivity were compared with a similar, previously reported amidoamine derivative gelator with two amide moieties. C13A2AOH and C17A2AOH gels prepared in water and organic solvents acted as ambidextrous low molecular mass gelators. X-ray diffraction and Fourier transform infrared spectroscopy analyses revealed that C13A2AOH and C17A2AOH formed lamellar-like aggregates in the gels, where the amide moieties were in a strong intermolecular hydrogen-bonding state. The gelation ability, i.e., the molar ratio of solvent to gelator, was significantly dependent on the length of the alkyl chain and the number of amide moieties. In addition, the C13A2AOH and C17A2AOH hydrogels exhibited highly pH-responsive gel-sol transitions. The gel-sol transition for the hydrogels was induced by protonation of the ternary amine and the transition was completely reversible by regulating only the pH without heating.
authors.affiliation: Department of Industrial Chemistry, Tokyo University of Science, Tokyo, Japan.
authors.forename: Clara
authors.initials: C
authors.lastname: Morita
authors.forename: Chika
authors.initials: C
authors.lastname: Kawai
authors.forename: Aoi
authors.initials: A
authors.lastname: Kikuchi
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Imura
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kawai
mesh_terms: D000577:Amides / Q000138:chemical synthesis / Q000737:chemistry*; D006358:Hot Temperature; D020100:Hydrogels / Q000138:chemical synthesis / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D010316:Particle Size; D044367:Phase Transition; D013499:Surface Properties
chemical_list: D000577:Amides; D020100:Hydrogels