title: Effect of headgroup chirality in nanoassemblies. Part 1. Self-assembly of D-isoascorbic acid derivatives in water.
abstract: L-(+)-Ascorbic acid and D-(-)-isoascorbic acid are epimers, with an opposite configuration at the C5 stereogenic chiral center. Single-chained surfactants that carry a L-ascorbic or d-isoascorbic acid residue as hydrophilic headgroup and an alkanoate tail as hydrophobic chain were synthesized. We refer to these as L-ASCn and D-ASCn, with n=8, 10, or 12. The role of the headgroup configuration in determining the nature of both the pure compounds and their nano assembly in aqueous dispersions were studied. Surface tension, infrared spectroscopy, differential scanning calorimetry, conductivity, small-angle X-ray scattering, and wide-angle X-ray diffractometry were used to characterize surfactant properties as a function of temperature and concentration. The L and D headgroup forms have significantly different hydration. This greatly affects the structure and stability of the aggregates in the micellar and coagel states.
authors.affiliation: Department of Chemistry and CSGI, University of Florence, 50019 Sesto Fiorentino (Firenze), Italy.
authors.forename: Moira
authors.initials: M
authors.lastname: Ambrosi
authors.forename: Pierandrea
authors.initials: P
authors.lastname: Lo Nostro
authors.forename: Emiliano
authors.initials: E
authors.lastname: Fratini
authors.forename: Luca
authors.initials: L
authors.lastname: Giustini
authors.forename: Barry W
authors.initials: BW
authors.lastname: Ninham
authors.forename: Piero
authors.initials: P
authors.lastname: Baglioni
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D019277:Entropy; D015394:Molecular Structure; D049329:Nanostructures / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013237:Stereoisomerism; D014867:Water / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D014867:Water; C005056:isoascorbic acid; D001205:Ascorbic Acid