Long-term stability of self-assembled monolayers of an aromatic bifunctional molecule during adsorption of silver colloidal particles

The long term stability of 4-carboxythiophenol (4-CTP) self-assembled monolayers (SAMs) grown on gold and alumina substrates under prolonged exposure to the silver colloidal solution is reported. Quartz crystal microgravimetry (QCM) measurements indicate a loss of mass from silver colloidal particle films formed on SAMs grown on alumina during prolonged immersion in the silver sol. The SAMs are also found to desorb from Au substrates immersed in the silver colloidal solution. QCM evidence for the adsorption and similar desorption processes occurring during immersion of bare alumina surfaces in colloidal solutions of Ag clusters capped with monolayers of 4-CTP is presented.