Phase diagrams of heteronuclear dimers adsorbed on a square lattice

Abstract

Monte Carlo simulation in the grand canonical ensemble has been performed to study phase transitions in monolayer films formed by heteronuclear dimers. The phase diagrams have been estimated for some model systems. The results reveal a great variety of vapor–liquid coexistence behaviors depending on the relative strengths of interactions between molecule segments. The structural transitions have been found.

Properties of the two-dimensional heterogeneous Lennard-Jones dimers: An integral equation study

“…If we take a 2D dimer and we add hydrogen bond interaction like in MB water, we can obtain models for alcohols like methanol and t-butanol. Most of the studies to understand the properties of dimers used computer simulations on a lattice [28][29][30][31][32][33][34][35][36] and some also on continuous-space. 27,37,38 This work is an extension of Ref.…”

Adsorption on the carbon nanotubes

“…N is the number of adsorbed dimers. The term NJ 1 is subtracted in the Hamiltonian since the summation over all the nearest-neighbor site pairs overestimates the total energy by including N bonds belonging to the N adsorbed dimmers [40][41][42]. By the Monte Carlo annealing, we obtained twelve different types of ground states of dimer adsorption on the (6, 0) SWCNT, more than the single-site adsorption.…”

“…The adsorbed diatomic molecules are modelled as dimers, which occupy two neighboring lattice sites, and we use the dimmer model to describe it [40][41][42]. The Hamiltonian of the System is given as:…”

Statistical Thermodynamics of Lattice Gas Models of Multisite Adsorption

“…There are papers devoted to the description of the first order phase transition such as "surface gas -surface liquid" [75,76,80]. The most important conclusion from all these studies is that with increasing molecular size the critical temperature shifts to higher values.…”

“…In the study of phase diagrams of these films interesting phenomena were found. In particular, the coexistence of three phases and a variety of structural transitions, and ordered linear type structure exists even at high temperatures [75].…”