Ultralow Adhesion and Friction of Fluoro-Hydro Alkyne-Derived Self-Assembled Monolayers on H-terminated Si(III)

S.P. Pujari, E. Spruijt, M.A. Cohen Stuart, C.J.M. van Rijn, J.M.J. Paulusse, H. Zuilhof

Research output: Contribution to journalArticleAcademicpeer-review

60 Citations (Scopus)

Abstract

New fluorine-containing terminal alkynes were synthesized and self-assembled onto Si(111) substrates to obtain fluorine-containing organic monolayers. The monolayers were analyzed in detail by ellipsometry, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared reflection absorption spectroscopy (FT-IRRAS), static water contact angle measurements (CA), and atomic force microscopy (AFM). The SAMs exhibit excellent hydrophobicity, with static water contact angles of up to 119° and low critical surface tensions of 5-20 mN/m depending on the number of F atoms per molecule. IRRAS confirmed the formation of highly ordered monolayers, as indicated by the antisymmetric and symmetric stretching vibrations of the CH(2) moieties at 2918-2920 and 2850-2851 cm(-1), respectively. Upon increasing the number of fluorine atoms in the alkyne chains from 0 to 17, the adhesion of bare silica probes to the SAMs in air decreases from 11.6 ± 0.20 mJ/m(2) for fluorine-free (F0) alkyne monolayers to as low as 3.2 ± 0.03 mJ/m(2) for a heptadecafluoro-hexadecyne (F17)-based monolayer. Likewise, the friction coefficient decreases from 5.7 × 10(-2) to 1.2 × 10(-2). The combination of high ordering, excellent hydrophobicity, low adhesion, and low friction makes these fluoro-hydro alkyne-derived monolayers highly promising candidates for use in high-performance microelectronic devices.
Original languageEnglish
Pages (from-to)17690-17700
JournalLangmuir
Volume28
Issue number51
DOIs
Publication statusPublished - 2012

Keywords

  • atomic-force microscopy
  • covalently attached monolayers
  • extremely mild attachment
  • silicon surfaces
  • organic monolayers
  • porous silicon
  • visible-light
  • x-ray
  • gold
  • films

Fingerprint

Dive into the research topics of 'Ultralow Adhesion and Friction of Fluoro-Hydro Alkyne-Derived Self-Assembled Monolayers on H-terminated Si(III)'. Together they form a unique fingerprint.

Cite this