[nanoPost] Barrier and release properties of thin model HDFD/Ag-plasma polymer nanocomposite fi

Research Centre Germany

Antibacterial properties of silver composite coatings are of increasing interest in medical and household applications.
While numerous reports demonstrate the positive antimicrobial properties of silver-based coatings, only little is known
about the precise relationship between silver content, silver ion release and toxic effects of silver composite films. For
commercial applications it is of high importance to achieve a sustained release of silver and to maximize the longterm
stability of composite films during release process.

Thin Heptadecafluoro-1-decene (HDFD) films can be tailored in their chemical composition and barrier properties by
means of plasma polymerization. Such films act as a rate-limiting barrier for the silver ions and by this means a sustained
release of silver can be achieved.

HDFD/Ag-plasma polymer nanocomposite films were synthesized by combining plasma polymerization of HDFD and
electron beam evaporation of silver. The thickness of the silver nanocomposite films was controlled in-situ by means of
quartz crystal microbalance during deposition process and determined ex-situ by spectroscopic ellipsometry. The
characterization of the nanocomposite films and the study of their stability during the release process were done by
means of TEM, XPS and UV-Vis Spectroscopy. In order to determine the barrier properties of the tailored nanocomposite
films, electrochemical impedance spectroscopy was carried out. Further, the release of the silver ions from the
nanocomposite films was investigated by means of atomic absorption spectroscopy. The performed measurements
illustrate the release mechanism of silver nanoparticles embedded in a highly crosslinked perfluorinated matrix and how
this leads to an effective release of silver.