Degradation of thin poly(lactic acid) films: Characterization by capacitance-voltage, atomic force microscopy, scanning electron microscopy and contact-angle measurements

Autor: Patrick Wagner, Matthias Bäcker, S. Menzel, M. Leinhos, Sebastian Schusser, Arshak Poghossian, Michael J. Schöning
Jazyk: angličtina
Rok vydání: 2013
Předmět:
Popis: For the development of new biopolymers and implantable biomedical devices with predicted biodegradability, simple, non-destructive, fast and inexpensive techniques capable for real-time in situ testing of the degradation kinetics of polymers are highly appreciated. In this work, a capacitive field-effect electrolyte-insulator-semiconductor (EIS) sensor has been applied for real-time in situ monitoring of degradation of thin poly(d,l-lactic acid) (PDLLA) films over a long-time period of one month. Generally, the polymer-modified EIS (PMEIS) sensor is capable of detecting any changes in the bulk, surface and interface properties of the polymer (e.g., thickness, coverage, dielectric constant, surface potential) induced by degradation processes. The time-dependent capacitance-voltage (C-V) characteristics of PMEIS structures were used as an indicator of the polymer degradation. To accelerate the PDLLA degradation, experiments were performed in alkaline buffer solution of pH 10.6. The results of these degradation measurements with the EIS sensor were verified by the detection of lactic acid (product of the PDLLA degradation) in the degradation medium. In addition, the micro-structural and morphological changes of the polymer surface induced by the polymer degradation have been systematically studied by means of scanning-electron microscopy, atomic-force microscopy, optical microscopy, and contact-angle measurements. © 2013 Elsevier Ltd. ispartof: pages:779-784 ispartof: Electrochimica Acta vol:113 pages:779-784 ispartof: location:Linz: AUSTRIA status: published
Databáze: OpenAIRE