Abstract
Poly(ethylene oxide) (PEO)-like thin films were successfully prepared by plasma-assisted vapor thermal deposition (PAVTD). PEO powders with a molar weight (Mw) between 1500 g/mol and 600,000 g/mol were used as bulk precursors. The effect of Mw on the structural and surface properties was analyzed for PEO films prepared at a lower plasma power. Fourier transform (FTIR-ATR) spectroscopy showed that the molecular structure was well preserved regardless of the Mw of the precursors. The stronger impact of the process conditions (the presence/absence of plasma) was proved. Molecular weight polydispersity, as well as wettability, increased in the samples prepared at 5 W. The influence of deposition plasma power (0–30 W) on solubility and permeation properties was evaluated for a bulk precursor of Mw 1500 g/mol. The rate of thickness loss after immersion in water was found to be tunable in this way, with the films prepared at the highest plasma power showing higher stability. The effect of plasma power deposition conditions was also shown during the permeability study. Prepared PEO films were used as a cover, and permeation layers for biologically active nisin molecule and a controlled release of this bacteriocin into water was achieved.
Highlights
Polymer materials with antimicrobial properties are of the interests to many industrial and scientific sectors
Poly(ethylene oxide) (PEO) of various molecular weights (1500, 6000, 20,000, and 600,000 g/mol, referenced further as 1.5k, 6k, 20k, and 600k precursors), poly(vinyl alcohol) Mowiol® 6-98, molar weight (Mw) ~47,000 g/mol (98–98.8 mol% hydrolysis), nisin standard from Lactococcus lactis, potassium chloride (KCl), ethylene glycol, and diiodomethane were obtained from Sigma-Aldrich
The dependence of the plasma-assisted vapor thermal deposition (PAVTD) thin film properties on the Mw of the bulk precursor was studied for materials deposited solely by thermal degradation/evaporation without plasma (0 W) or with mild plasma repolymerization (RF power 5 W)
Summary
Polymer materials with antimicrobial properties are of the interests to many industrial and scientific sectors. For this purpose, a number of methods aiming at biomolecules’ attachment to polymer surfaces have been developed, such as adsorption, graft polymerization, or the formation of self-assembled monolayers [1,2,3,4]. The efficiency of the bioactive polymer system lies in the ability of the polymer material to selectively bind the active molecule and its consequent slow and controlled release [6,7]. Environmentally favourable methods that allow for the chemical and mechanical properties of polymers to be controlled. Called “plasma polymerization” or plasma enhanced chemical vapor deposition (PECVD) uses plasma to activate and Polymers 2020, 12, 1263; doi:10.3390/polym12061263 www.mdpi.com/journal/polymers
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
