Static properties of a dendrimer with generation g = 5 with positively charged terminal groups in an athermal solvent are studied by lattice Monte Carlo simulations using the cooperative motion algorithm as the tossing scheme. The calculations are performed both for a salt-free system with neutralizing counterions and for a small amount of added monovalent and divalent salt. The full Coulomb potential and the excluded volume interactions between ions and beads are taken explicitly into account with the reduced temperature tau, the number of salt cations (anions) n(s), and salt valence z(s) as the simulation parameters. The bahaviour of the systems is analyzed by the mean effective charge per end-bead , Coulomb mean energy , mean-square radius of gyration , pair correlation functions g(alphabeta), and charge density rho(ch). The simulations show that for n(s)> or = 0 and decreasing tau: (a) there is encapsulation in the dendrimer and condensation onto the terminal groups of anions accompanied by a monotonic decrease in and and by subsequent swelling and shrinking of the molecule; (b) encapsulation, condensation and shrinking are the most significant and swelling weaker for |z(s)| = 2; (c) penetration of salt cations into the dendrimer is minor when compared to that of anions; (d) rho(ch) is reduced and becomes negative close to the center of mass of the dendrimer and on its periphery; (e) for the considered n(s) > 0, unlike divalent salt ions the monovalent ones cause slight effects when compared to the salt-free case.

Static, structural properties of dendrimers with generations ranging from g = 3 up to g = 7 with charged, monovalent terminal groups and neutralizing counterions in an athermal solvent are studied by lattice Monte Carlo simulations using the cooperative motion algorithm as the tossing scheme. The full Coulomb potential and the excluded volume interactions between pairs of ions and beads are taken explicitly into account with the reduced temperature T* as the main, variable parameter. In particular, the influence of variation of the latter on the mean effective charge per end-bead , total mean energy , mean-square radius of gyration , and mean-square centre-to-end-bead distance is analysed and the molecular weight dependences of , are shown. The simulations indicate that condensation of counterions onto the end-beads occurs as T* is lowered. This effect is accompanied by weak, gradual swelling and shrinking of the molecules.

Taking into account the full Coulomb potential and the excluded volume interactions, properties of dendrimers with generations g = 5, 6 with charged terminal groups and counterions in an athermal solvent are examined by lattice Monte Carlo simulations. The study treats counterions explicitly and focuses on the local structure of the systems inspected by pair correlation functions g ab that provide information on distributions of monomers, terminal groups and ions in space at various temperatures T * . Special emphasis is placed on counterions and their role they play in causing conformational changes of the molecules. The simulations show that counterions penetrate the interior of the dendrimers, and there is a major increase in their concentration there as T * decreases. Some of them condense onto the terminal groups and a reduction in the mean effective charge Q of the dendrimers appears. Within the range of temperatures where the condensation (as a function of T * ) is sharp the molecules weakly swell up when compared to their size at the other temperatures. This kind of behaviour is also reflected by the distributions of monomers and terminal groups.