Surface characterisation of NH3 plasma treated polyamide 6 foils

Lidija Tušek, Mirko Nitschke, Carsten Werner, Karin Stana Kleinschek, Volker Ribitsch

Research output: Contribution to journalArticleResearchpeer-review

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 languageEnglish
Pages (from-to)81-95
Number of pages15
JournalColloids and Surfaces A: Physicochemical and Engineering Aspects
Volume195
Issue number1-3
DOIs
Publication statusPublished - 30 Dec 2001
Externally publishedYes

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Keywords

  • Ammonia plasma
  • Electrokinetic properties
  • Polyamide 6
  • Surface analysis

ASJC Scopus subject areas

  • Surfaces and Interfaces
  • Physical and Theoretical Chemistry
  • Colloid and Surface Chemistry

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