Interfacial Behavior of a Reacting Alkoxysilane Monolayer System

We report here the results on the investigations of the dynamic interfacial behavior of a trifunctional alkoxysilane, octadecyltrimethoxysilane (OTMS) as it is reacting at the air‐water interface. We have investigated both the Π‐A isotherms and A(t) isobars of OTMS at acidic subphases. An attempt to analyze the kinetics of the reaction in the monolayer was limited to the early stages of the reactions and only describes the kinetics of hydrolysis. We also confirmed by rheological measurements that this system does indeed form a network inefficiently and the resulting structure most likely consists of extensive linear segments as has been suggested in earlier reports. The general rheological characteristic indicates the product to have high molecular weight. The product also exhibited a 2D sol‐gel transition that has general features of a percolating network. However, the scaling behavior does not follow exactly that predicted; several reasons for this are discussed. A(t) isobars of OTMS at various subphase pH