Adsorption thermodynamics of a lattice–gas model with non-additive lateral interactions on triangular and honeycomb lattices

Lattice-gas model of nonadditive interacting particles on nanotube bundles

“…The behavior of the curves and the corresponding structures have already been reported in Ref. 40 for a twodimensional system. This finding is not surprising, because the only effect of the longitudinal repulsive interactions is to avoid the formation of occupied-occupied pairs of sites along the channels.…”

“…When P L(T) = 1, the additive case is recovered. [36][37][38][39][40] The adsorption process is simulated through MC simulations in the grand canonical ensemble. [56][57][58] We consider the system in contact with an ideal gas at temperature T and chemical potential μ.…”

“…[56][57][58] We consider the system in contact with an ideal gas at temperature T and chemical potential μ. 39,40 The array as well as the adsorbate are inert upon adsorption. We use the Metropolis scheme 59 to satisfy the principle of detailed balance.…”

“…60 and 61) is used for nonadditive interactions. [36][37][38] The canonical partition function Q(M,N,T,P L ,P T ) for N particles adsorbed on an array of M sites at temperature T and nonadditive lateral interactions is 39,40…”

“…In fact, the deviation of an additive behavior appears to be especially significant in the case of chemisorption where the valence electrons are either concentrated in forming a single bond between two isolated atoms or shared among all neighbors which are occasionally occupying sites in the first coordination shell of the central atom. [36][37][38][39][40] Among the effects caused by nonadditive interactions, it is possible to mention the following: 39,40 (i) the symmetry of particle-vacancy (valid for additive interactions) is broken and, consequently, the adsorption thermodynamic quantities (adsorption isotherms, configurational entropy, differential heat of adsorption, etc.) are asymmetric with respect to half coverage; (ii) the formation of "k-mers" (chains of monomers adsorbed on k adjacent lattice sites) is favored at high coverage; (iii) a rich variety of ordered structures are observed in the adlayer; and (iv) for repulsive couplings, first-and second-order phase transitions occur in the adsorbate at different concentrations.…”