piperidines and n-hexadecane

Self-standing films of cellulose nanofibril derivatives were prepared via oxidation by the 2,2,6,6-tetramethyl-1-piperidinyloxy radical and amidation with octadecylamine (ODA). The transparency and rigidity of the films decreased and their flexibility increased as the amide/carboxyl ratio increased. The introduction of the ODA also resulted in rising contact angles of water (from 43.5° to 117°) and oleic acid (from 22.5° to 57.1°). Furthermore, the films exhibited unique oil repellency: a drop of hexadecane slipped without tailing on the surface modified by ODA. This phenomenon was observed after moderate modification (water contact angle: 95-114°) and was absent for the films with the lowest and highest extents of modification. Then, the antifingerprint property of the films was examined by means of the powder test, and a reduction in fingerprints on the films was demonstrated. These results suggest the usefulness of developing transparent, self-standing oil-repellent films without perfluorinated compounds for antifingerprint and other antifouling applications.

Topics: Alkanes; Cellulose, Oxidized; Cyclic N-Oxides; Elastic Modulus; Fluorine; Free Radicals; Hydrophobic and Hydrophilic Interactions; Microscopy, Electron, Scanning; Nanofibers; Oleic Acid; Oxidation-Reduction; Piperidines; Powders; Spectroscopy, Fourier Transform Infrared; Surface Properties; Tensile Strength; Thermogravimetry; Water; X-Ray Diffraction