ISSN:
1432-0630
Keywords:
PACS: 07.79.-v; 68.35.Bs
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
3 N4 tip functionalized with OHgroups 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=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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s003390051143
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