Reversible Random Sequential Adsorption of Dimers on a Triangular Lattice

TL;DR

This paper presents simulations of reversible random sequential adsorption of dimers on various lattices, revealing the significance of two-particle events in the dynamics, with implications for modeling Ca++ binding in Langmuir monolayers.

Contribution

It extends previous models to include reversibility and confirms the role of two-particle events in two-dimensional lattice adsorption dynamics.

Findings

Long-time behavior dominated by two-particle events.

Confirmed importance of two-particle events in 2D lattice.

Dynamics consistent with experimental pH effects in Langmuir monolayers.

Abstract

We report on simulations of reversible random sequential adsorption of dimers on three different lattices: a one-dimensional lattice, a two-dimensional triangular lattice, and a two-dimensional triangular lattice with the nearest neighbors excluded. In addition to the adsorption of particles at a rate K+, we allow particles to leave the surface at a rate K-. The results from the one-dimensional lattice model agree with previous results for the continuous parking lot model. In particular, the long-time behavior is dominated by collective events involving two particles. We were able to directly confirm the importance of two-particle events in the simple two-dimensional triangular lattice. For the two-dimensional triangular lattice with the nearest neighbors excluded, the observed dynamics are consistent with this picture. The two-dimensional simulations were motivated by measurements of Ca++ binding to Langmuir monolayers. The two cases were chosen to model the effects of changing pH in the experimental system.