title: Size effect of ZnO nanorods on physicochemical properties of plasticized starch composites.
abstract: This work demonstrates that the size of ZnO nanorods (ZnONR) with similar aspect ratio determines several physicochemical and microbiological properties of thermoplastic starch composites (TPS/ZnONR) at a given concentration of ZnONRs. A combination of sol-gel and hydrothermal methods was developed to synthesize ZnONR with different sizes but similar aspect ratios. Starch composites containing 1wt.% of ZnONR were prepared by casting. Composites with smaller size nanorods (ZnONR-S) showed more efficiency in shielding UVA radiation and had a higher solubility and water vapor permeability than those with larger nanorods (ZnONR-L). Mechanical properties, biodegradability and antibacterial activity were also influenced by the size of the ZnONR. X-ray diffraction analysis showed that composites with ZnONR-S maintained the typical B-V type starch structure, intensifying the V-type starch structure peaks, while composite with ZnONR-L induced the formation of an amorphous structure, preventing starch retrogradation during storage. Properties affected by nanorods size are fundamental in determining composite applications.
authors.affiliation: Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales, Departamento de Física, Laboratorio de Polímeros y Materiales Compuestos (LPM&C). Instituto de Física de Buenos Aires (IFIBA-CONICET). Ciudad Universitaria (1428), Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: L
authors.initials: L
authors.lastname: Guz
authors.affiliation: Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales, Departamento de Física, Laboratorio de Polímeros y Materiales Compuestos (LPM&C). Instituto de Física de Buenos Aires (IFIBA-CONICET). Ciudad Universitaria (1428), Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: L
authors.initials: L
authors.lastname: Famá
authors.affiliation: Instituto de Investigación e Ingeniería Ambiental, CONICET, Universidad Nacional de San Martín, 25 de Mayo y Francia (1650), San Martín, Provincia de Buenos Aires, Argentina. Electronic address: rjcandal@gmail.com.
authors.forename: R
authors.initials: R
authors.lastname: Candal
authors.affiliation: Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales, Departamento de Física, Laboratorio de Polímeros y Materiales Compuestos (LPM&C). Instituto de Física de Buenos Aires (IFIBA-CONICET). Ciudad Universitaria (1428), Ciudad Autónoma de Buenos Aires, Argentina. Electronic address: goyanes@df.uba.ar.
authors.forename: S
authors.initials: S
authors.lastname: Goyanes
keywords: Bactericidal activity; Biodegradability; Starch composite; ZnO nanorods size