Acta Phys. -Chim. Sin. ›› 1997, Vol. 13 ›› Issue (04): 293-296.doi: 10.3866/PKU.WHXB19970402

• Communication • Previous Articles     Next Articles

Force Titration of Self-Assembled Monolayer Using Chemical Force Microscopy

He Hui-Xin,Li Chun-Zeng,Wang Jun-Mei,Zhang Hao-Li,Xu Xiao-Jie,Liu Zhong-Fan   

  1. Center for Institute Materials Research(CIMR),College of Chemistry and Molecular Engineering,Peking University,Beijing 100871,China
  • Received:1996-12-27 Revised:1997-01-20 Published:1997-04-15
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Abstract:

 The concept of force titration was firstly proposed based on the technique of Chemical Force Microscopy (CFM). Self-Assembled Monolayer (SAM) on substrate surface can be titrated with buffer solutions at a nanometer scale by measuring the adhesion force between the SAM-modified substrate and probe tip. The plot of adhesion force vs pH value was termed as force titration curve. As an example, the titration behavior of w-mercaptoundecanoic acid monolayer on gold has been studied. It was found that there is a big hump around pH 5~6 in its force titration curve. Taking the contact angle titration result together, an interaction model for the monolayer was suggested from the chemical hysteresis point of view.

Key words: Chemical force microscopy(CFM), Adhesion force, Force titration, Self-assembled monolayer(SAM)