A. Datta

Order in molecular liquids near solid-liquid interfaces

Abstract Much less is known about structure at solid–liquid interfaces than at solid or liquid surfaces, largely because it is more difficult for experimental probes to penetrate into an interface. In recent years, the availability of synchrotron radiation (which is intense and collimated, and whose energy and thus penetration depth can be varied) has made scattering experiments at such interfaces possible. This article reviews some recent studies of ordering at the liquid side of a solid–liquid interface.

Using X-rays to characterize the process of self-assembly in real time

Abstract We have performed in situ X-ray reflectivity studies of the growth of octadecyltrichlorosilane (OTS) monolayers on oxidized Si(111) from solutions in heptane. We find that for all concentrations, the film grows through the formation of islands of vertical molecules. The coverage follows a simple Langmuir form as a function of time, except for very low concentration solutions at early times, where a time offset is required to fit the curve. We have also examined films removed from solution, and we find that rinsing removes molecules and causes the remaining molecules to tilt. Thus, samples studied using the ‘interrupted growth’ technique are not representative of the actual growth process.