title: Nanoengineered Eggshell-Silver Tailored Copolyester Polymer Blend Film with Antimicrobial Properties.
abstract: In this study, the reinforcement effect of different proportions of eggshell/silver (ES-Ag) nanomaterial on the structural and antimicrobial properties of 70/30 poly(butylene-co-adipate terephthalate)/polylactic acid (PBAT/PLA) immiscible blends was investigated. The ES-Ag was synthesized using a single step ball milling process and characterized with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). These results confirmed the existence of silver nanoparticles (Ag NPs) in the interstitial spaces of the eggshell particles. The thin films in this study were prepared using hot melt extrusion and 3D printing for mechanical and antimicrobial testing, respectively. These films were also characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), XRD, tensile testing, and antimicrobial analysis. It was found that the incorporation of ES-Ag (0.5-2.0% content) compromised the tensile properties of the blend, due to poor interaction between the matrix and the ES-Ag in the ternary systems, but thermal analysis revealed improvement in the onset of degradation temperature and char yield at 500 °C. Though film toughness was better than that of PLA, the strength was lower, yet synergistic to those of PBAT and PLA. In general, the PBAT/PLA/ES-Ag ternary system had properties intermediate to those of the pure polymers. In vitro assessment of the antimicrobial activity of these films conducted on Listeria monocytogenes and Salmonella Enteritidis bacteria revealed that the blend composite films possessed bacteriostatic effects, due to the immobilized ES-Ag nanomaterials in the blend matrix. Atomic absorption spectroscopy (AAS) analysis of water and food samples exposed to the films showed that Ag NPs were not released in distilled water and chicken breast after 72 and 168 h, respectively.
authors.affiliation: Department of Materials Science and Engineering, College of Engineering, and ‡Department of Pathobiology, College of Veterinary Medicine, Tuskegee University , Tuskegee, Alabama 36088, United States.
authors.forename: Boniface J
authors.initials: BJ
authors.lastname: Tiimob
authors.affiliation: Department of Materials Science and Engineering, College of Engineering, and ‡Department of Pathobiology, College of Veterinary Medicine, Tuskegee University , Tuskegee, Alabama 36088, United States.
authors.forename: Gregory
authors.initials: G
authors.lastname: Mwinyelle
authors.affiliation: Department of Materials Science and Engineering, College of Engineering, and ‡Department of Pathobiology, College of Veterinary Medicine, Tuskegee University , Tuskegee, Alabama 36088, United States.
authors.forename: Woubit
authors.initials: W
authors.lastname: Abdela
authors.affiliation: Department of Materials Science and Engineering, College of Engineering, and ‡Department of Pathobiology, College of Veterinary Medicine, Tuskegee University , Tuskegee, Alabama 36088, United States.
authors.forename: Temesgen
authors.initials: T
authors.lastname: Samuel
authors.affiliation: Department of Materials Science and Engineering, College of Engineering, and ‡Department of Pathobiology, College of Veterinary Medicine, Tuskegee University , Tuskegee, Alabama 36088, United States.
authors.forename: Shaik
authors.initials: S
authors.lastname: Jeelani
authors.affiliation: Department of Materials Science and Engineering, College of Engineering, and ‡Department of Pathobiology, College of Veterinary Medicine, Tuskegee University , Tuskegee, Alabama 36088, United States.
authors.forename: Vijaya K
authors.identifier: http://orcid.org/0000-0002-3962-1686
authors.initials: VK
authors.lastname: Rangari
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology; D004528:Egg Shell / Q000737:chemistry*; D018857:Food Packaging / Q000295:instrumentation; D053761:Nanocomposites / Q000737:chemistry*; D011091:Polyesters / Q000737:chemistry*; D012834:Silver / Q000737:chemistry* / Q000494:pharmacology*; D013718:Tensile Strength; D014961:X-Ray Diffraction
chemical_list: D000900:Anti-Bacterial Agents; D011091:Polyesters; D012834:Silver; C033616:poly(lactide)
keywords: 3D-printing; antimicrobial films; biocide; extrusion; flexible polymer blends