Abstract
Nitrogen-containing plasmas are widely used to improve wettability, printability, bondability, and biocompatibility of polymer surfaces. Plasma-treatments fed with NH3 give rise to N-functionalities, such as amino (=NH2), imino (=CH=NH), cyano (=C=N) and others on polymers, plus oxygen-containing groups due to post-plasma atmospheric oxidation. This work deals with NH3 plasma treatment of PA 6 foils and the evaluation of surface modification as a function of treatment time. The introduced functionalities were observed by streaming potential measurements (surface charge), X-ray photoelectron spectroscopy analysis (nature of introduced functionalities), atomic force microscopy (surface topography), and contact angle measurement (assessment of treatment effect). The results show that the introduction of N-containing groups is increasing with longer treatment time only to a certain extent where the negative effect of surface destruction prevails over the positive effect of introduction of functional groups. The treatment causes a shift of the isoelectric point (IEP) toward pH of 6.2 as compared to 4.2 found for the untreated foil. If the treatment time is longer than 1 min the IEP is shifted to lower pH, the number of amino groups on the surface is reduced and the contact angle is increased.
Original language | English |
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Pages (from-to) | 81-95 |
Number of pages | 15 |
Journal | Colloids and Surfaces A: Physicochemical and Engineering Aspects |
Volume | 195 |
Issue number | 1-3 |
DOIs | |
Publication status | Published - 30 Dec 2001 |
Externally published | Yes |
Keywords
- Ammonia plasma
- Electrokinetic properties
- Polyamide 6
- Surface analysis
ASJC Scopus subject areas
- Surfaces and Interfaces
- Physical and Theoretical Chemistry
- Colloid and Surface Chemistry