title: In situ sonochemical synthesis of ZnO particles embedded in a thermoplastic matrix for biomedical applications.
abstract: Zinc oxide particles were synthesized and dispersed in situ in a polystyrene (PS) matrix using ultrasound. PS ultrasonic degradation was investigated at different polymer concentrations in organic solvent in contact with aqueous media prior to the particle synthesis. Decrease in weight-average molecular weight (Mw) was strongly dependent on polymer concentration in organic solvent and sonication time: degradation occurred less at higher polymer concentration, yet increased with longer times of more than 30min. The ZnO particles with a 800nm flower-like morphology were dispersed in the polystyrene matrix in situ; the composite presented both a lower average molecular weight (Mw) and lower number average molecular weight Mn when compared to pristine polystyrene, however thermal degradation temperature and Young's modulus were similar to the pristine polystyrene. The composite prepared in situ presented lower particle aggregation in comparison with ZnO commercially dispersed with ultrasound under the same conditions. Antibacterial activity of the ZnO/PS coating was tested against Escherichia coli (Gram-negative bacteria; DMS No. 10290) by evaluating bacterial growth inhibition after 20h on contact with the film surface. The results indicated that bacterial growth was inhibited in the medium in contact with the composite prepared in situ compared to the film of composite prepared by mixing and the pristine PS. This study showed the potential use of ZnO/PS composite prepared in situ as antibacterial coatings.
authors: Programa de Pós-Graduação em Ciência e Tecnologia de Materiais POSMAT, Universidade Estadual Paulista (UNESP), Av. Eng. Luiz Edmundo Carrijo Coube 14-01, 17033-360 Bauru, São Paulo, Brazil; Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), Wiener Straße 12, 28359 Bremen, Germany.
authors: Yendry Regina Corrales
authors: YRC
authors: Ureña
authors: Departamento de Engenharia de Materiais, Universidade Federal de São Carlos UFSCAR, Rodovia Washington Luís 310, 13565-905 São Carlos, São Paulo, Brazil.
authors: Silvia Helena Prado
authors: SHP
authors: Bettini
authors: Departamento de Engenharia de Materiais, Universidade Federal de São Carlos UFSCAR, Rodovia Washington Luís 310, 13565-905 São Carlos, São Paulo, Brazil.
authors: Pablo Riveros
authors: PR
authors: Muñoz
authors: Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), Wiener Straße 12, 28359 Bremen, Germany.
authors: Linda
authors: L
authors: Wittig
authors: Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), Wiener Straße 12, 28359 Bremen, Germany.
authors: Klaus
authors: K
authors: Rischka
authors: Departamento de Física, Faculdade de Ciências, Universidade Estadual Paulista (UNESP), Av. Eng. Luiz Edmundo Carrijo Coube 14-01, 17033-360 Bauru, São Paulo, Brazil.
authors: Paulo N
authors: PN
authors: Lisboa-Filho
mesh_terms: D014465:Ultrasonics; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D015034:Zinc Oxide
keywords: Antibacterial activity; Degradation; In situ; Polystyrene; Ultrasound; Zinc oxide