Mechanism of Reactive Wetting and Direct Visual Determination of the Kinetics of Self-Assembled Monolayer Formation

Reactive wetting (RW) of alkane thiols and disulfides on gold is studied experimentally using the wet stamping technique. Theoretical description based on Langevin dynamics is developed to explain the experimental results and to clarify the physical processes underlying RW. In this description, thermal fluctuations of the three-phase contact line combine with the surface reaction to gradually build a low-energy self-assembled monolayer (SAM) onto which the front propagates. The results of the model match the experiments and allow determination of the kinetic rate constants of SAM formation.