info:eu-repo/semantics/article
Configurational entropy of adsorbed rigid rods: Theory and Monte Carlo simulations
Fecha
2009-05Registro en:
Centres, Paulo Marcelo; Ramirez Pastor, Antonio Jose; Configurational entropy of adsorbed rigid rods: Theory and Monte Carlo simulations; Elsevier Science; Physica A: Statistical Mechanics and its Applications; 388; 10; 5-2009; 2001-2019
0378-4371
CONICET Digital
CONICET
Autor
Centres, Paulo Marcelo
Ramirez Pastor, Antonio Jose
Resumen
The configurational entropy of straight rigid rods of length k (k-mers) adsorbed on square, honeycomb, and triangular lattices is studied by combining theory and Monte Carlo (MC) simulations in grand canonical and canonical ensembles. Three theoretical models to treat k-mer adsorption on two-dimensional lattices have been discussed: (i) the Flory-Huggins approximation and its modification to address linear adsorbates; (ii) the well-known Guggenheim-DiMarzio approximation; and (iii) a simple semi-empirical model obtained by combining exact one-dimensional calculations, its extension to higher dimensions and Guggenheim-DiMarzio approach. On the other hand, grand canonical and canonical MC calculations of the configurational entropy were obtained by using a thermodynamic integration technique. In the second case, the method relies upon the definition of an artificial Hamiltonian associated with the system of interest for which the entropy of a reference state can be exactly known. Thermodynamic integration is then applied to calculate the entropy in a given state of the system of interest. Comparisons between MC simulations and theoretical results were used to test the accuracy and reliability of the models studied.