Publication detail

Determination of NH2 concentration on 3-aminopropyl tri-ethoxy silane layers and cyclopropylamine plasma polymers by liquid-phase derivatization with 5-iodo 2-furaldehyde

MANAKHOV, A. ČECHAL, J. MICHLÍČEK, M. SHTANSKY, D.

Original Title

Determination of NH2 concentration on 3-aminopropyl tri-ethoxy silane layers and cyclopropylamine plasma polymers by liquid-phase derivatization with 5-iodo 2-furaldehyde

Type

journal article in Web of Science

Language

English

Original Abstract

The quantification of concentration of primary amines, e.g. in plasma polymerized layers is a very important task for surface analysis. However, the commonly used procedure, such as gas phase derivatization with benzaldehydes, shows several drawbacks, the most important of which are the side reaction effects. In the present study we propose and validate a liquid phase derivatization using 5-iodo 2-furaldehyde (IFA). It was demonstrated that the content of NH2 groups can be determined from the atomic concentrations measured by X-ray photoelectron spectroscopy (XPS), in particular from the ratio of I 3d and N 1s peak intensities. First, we demonstrate the method on a prototypical system such as 3-aminopropyl triethoxy silane (APTES) layer. Here the XPS analysis carried out after reaction of APTES layer with IFA gives the fraction of primary amines (NH2/N) of 38.3 ±7.9%. Comparing this value with that obtained by N 1s curve fitting of APTES layer giving 40.9 ±9.5% of amine groups, it can be concluded that all primary amines were derivatized by reaction with IFA. The second system to demonstrate the method comprises cyclopropylamine (CPA) plasma polymers that were free from conjugated imines. In this case the method gives the NH2 fraction ∼8.5%. This value is closely matching the NH2/N ratio estimated by 4-trifluoromethyl benzaldehyde (TFBA) derivatization. The reaction of IFA with CPA plasma polymer exhibiting high density of conjugated imines revealed the NH2/N fraction of ∼10.8%. This value was significantly lower compared to 17.3% estimated by TFBA derivatization. As the overestimated density of primary amines measured by TFBA derivatization is probably related to the side reaction of benzaldehydes with conjugated imines, the proposed IFA derivatization of primary amines can be an alternative procedure for the quantification of surface amine groups.

Keywords

Amine layers APTES Derivatization Plasma polymers XPS

Authors

MANAKHOV, A.; ČECHAL, J.; MICHLÍČEK, M.; SHTANSKY, D.

Released

31. 8. 2017

ISBN

0169-4332

Periodical

Applied Surface Science

Year of study

414

Number

1

State

Kingdom of the Netherlands

Pages from

390

Pages to

397

Pages count

8

URL

https://www.sciencedirect.com/science/article/abs/pii/S0169433217311546

BibTex

@article{BUT139932,
  author="Anton {Manakhov} and Jan {Čechal} and Miroslav {Michlíček} and Dmitry V. {Shtansky}",
  title="Determination of NH2 concentration on 3-aminopropyl tri-ethoxy
silane layers and cyclopropylamine plasma polymers by liquid-phase
derivatization with 5-iodo 2-furaldehyde",
  journal="Applied Surface Science",
  year="2017",
  volume="414",
  number="1",
  pages="390--397",
  doi="10.1016/j.apsusc.2017.04.127",
  issn="0169-4332",
  url="https://www.sciencedirect.com/science/article/abs/pii/S0169433217311546"
}