Force titration of amino group-terminated self-assembledmonolayers using chemical force microscopy

H. Zhang, H. X. He, J. Wang, T. Mu, Z. F. Liu

Research output: Contribution to journalArticle

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Abstract

Chemical force microscopy (CFM) was used to measure the adhesion force between an Au-coated Si3N4 tip functionalized with OH groups and a silicon substrate functionalized with NH2 groups. The curve of the adhesion force as a function of the solution pH value (force titration curve) was obtained. The pK1/2 of surface NH2 groups estimated from the force titration curve is 7:4, about 3 pK units lower than the pK value of NH2 functionality in aqueous solution, and in nice agreement with the value of pK1/2 D 7:6 determined by conventional contact angle titration. The surface pK1/2 value that we obtained from the force titration or contact angle titration is the apparent surface pK value, which is expressed as the corresponding bulk solution pH value at which the functional groups at the interface are half-ionized.

Original languageEnglish (US)
JournalApplied Physics A: Materials Science and Processing
Volume66
Issue numberSUPPL. 1
DOIs
StatePublished - 1998

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Titration
Microscopic examination
Contact angle
Adhesion
Silicon
Functional groups
Substrates

ASJC Scopus subject areas

  • Materials Science(all)
  • Chemistry(all)

Cite this

Force titration of amino group-terminated self-assembledmonolayers using chemical force microscopy. / Zhang, H.; He, H. X.; Wang, J.; Mu, T.; Liu, Z. F.

In: Applied Physics A: Materials Science and Processing, Vol. 66, No. SUPPL. 1, 1998.

Research output: Contribution to journalArticle

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AU - Liu, Z. F.

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