Dresden 2017 – wissenschaftliches Programm
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DS: Fachverband Dünne Schichten
DS 34: Organic Thin Films II
DS 34.1: Vortrag
Mittwoch, 22. März 2017, 15:00–15:15, CHE 91
Crystallinity and Degradability of Nano- and Microscaled Biopolymer Thin Films — Preetam Anbukarasu1, Dominic Sauvageau1, and •Anastasia Elias1,2 — 1Chemical and Materials Engineering, University of Alberta, Edmonton, Canada — 2Leibniz-Institut für Polymerforschung Dresden e. V.
Enzymatically-degradable polymer thin films are attractive for biomedical, packaging, micro-electronic and agricultural applications. The stability and degradability of these materials are known to depend on both the parameters under which they are processed, and on the environmental conditions under which degradation occurs. Processing conditions are especially relevant for semi-crystalline polymers, since the degree of crystallinity of a material is an important determinant of its degradability.
In this work, we examine the effect of nano-scale dimensional constraint on the crystallinity and enzymatic degradability of polyhydroxybutyrate (PHB), a biopolymer. The physical properties of solution-cast PHB films of varying thicknesses were examined by atomic force microscopy (AFM, lamella orientation & surface profile) and x-ray diffraction (XRD, crystallinity & crystal anisotropy). The enzymatic degradability was tested using a diffraction grating-based optical sensor. We found that as the thickness of the samples was reduced from 5 um to less than 100 nm, the crystallinity of the films decreased, while the rate of degradation increased. However, below 100 nm, surprisingly slow degradation rates were observed. This occurs due to the fact that these films are amorphous, inhibiting the binding of the enzymes.