Influence of monovalent ion size on colloidal forces probed by Monte Carlo simulations

2011 ◽  
Vol 13 (29) ◽  
pp. 13349 ◽  
Author(s):  
José Guadalupe Ibarra-Armenta ◽  
Alberto Martín-Molina ◽  
Manuel Quesada-Pérez
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Colloidal Forces ◽  
Monovalent Ion ◽  
Ion Size

scholarly journals Ion-mediated interactions between like-charged polyelectrolytes with bending flexibility

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yitong Zheng ◽  
Cheng Lin ◽  
Jin-Si Zhang ◽  
Zhi-Jie Tan
Keyword(s):  
Monte Carlo ◽  
Nucleic Acids ◽  
Monte Carlo Simulations ◽  
Conformational Space ◽  
Potentials Of Mean Force ◽  
Monovalent Ion

AbstractIon-mediated interactions between polyelectrolytes (PEs) are crucial to the properties of flexible biopolymers such as nucleic acids and proteins but the effect of PE flexibility on such interactions has not been explicitly addressed until now. In this work, the potentials of mean force (PMFs) between like-charged PEs with different bending flexibility have been investigated by Monte Carlo simulations and a cylindrical confinement around each PE was involved to model two PEs in an array. We found that in the absence of trivalent salt, the PMFs between like-charged PEs in an array are apparently repulsive while the bending flexibility can visibly decrease the repulsive PMFs. With the addition of high trivalent salt, the PMFs become significantly attractive whereas the attractive PMFs can be apparently weakened by the bending flexibility. Our analyses reveal that the effect of bending flexibility is attributed to the increased PE conformational space, which allows the PEs to fluctuate away to decrease the monovalent ion-mediated repulsion or to weaken the trivalent ion-mediated attraction through disrupting trivalent ion-bridging configuration. Additionally, our further calculations show that the effect of bending flexibility on the ion-mediated interactions is less apparent for PEs without cylindrical confinement.

Testing a modified model of the Poisson–Boltzmann theory that includes ion size effects through Monte Carlo simulations

2009 ◽  
Vol 11 (2) ◽  
pp. 309-316 ◽  
Author(s):  
José Guadalupe Ibarra-Armenta ◽  
Alberto Martín-Molina ◽  
Manuel Quesada-Pérez
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Size Effects ◽  
Modified Model ◽  
Poisson Boltzmann ◽  
Ion Size

Monte Carlo simulations of the electrical double layer forces in the presence of divalent electrolyte solutions: effect of the ion size

Soft Matter ◽  
2011 ◽  
Vol 7 (4) ◽  
pp. 1441-1449 ◽  
Author(s):  
Alberto Martín-Molina ◽  
José Guadalupe Ibarra-Armenta ◽  
Enrique González-Tovar ◽  
Roque Hidalgo-Álvarez ◽  
Manuel Quesada-Pérez
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Double Layer ◽  
Electrical Double Layer ◽  
Electrolyte Solutions ◽  
Ion Size

scholarly journals Specific ion effects on the electrokinetic properties of iron oxide nanoparticles: experiments and simulations

2015 ◽  
Vol 17 (26) ◽  
pp. 17069-17078 ◽  
Author(s):  
Fernando Vereda ◽  
Alberto Martín-Molina ◽  
Roque Hidalgo-Alvarez ◽  
Manuel Quesada-Pérez
Keyword(s):  
Monte Carlo ◽  
Iron Oxide ◽  
Monte Carlo Simulations ◽  
Iron Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Water Interface ◽  
Electrokinetic Properties ◽  
Specific Ion Effects ◽  
Ion Effects ◽  
Ion Size

Specific ion effects have been observed in the magnetite/water interface. Monte Carlo simulations qualitatively explain them in terms of ion size and ionic polarizabilities.

Low-voltage EDS of magnesium ferrite Dendrites in a FEG-SEM

1996 ◽  
Vol 54 ◽  
pp. 478-479
Author(s):  
Matthew T. Johnson ◽  
Ian M. Anderson ◽  
Jim Bentley ◽  
C. Barry Carter
Keyword(s):  
Monte Carlo ◽  
Quantitative Analysis ◽  
Monte Carlo Simulations ◽  
Cross Section ◽  
Spatial Resolution ◽  
Low Voltage ◽  
Magnesium Ferrite ◽  
X Ray ◽  
Interaction Volume ◽  
Ferrite Spinel

Energy-dispersive X-ray spectrometry (EDS) performed at low (≤ 5 kV) accelerating voltages in the SEM has the potential for providing quantitative microanalytical information with a spatial resolution of ∼100 nm. In the present work, EDS analyses were performed on magnesium ferrite spinel [(MgxFe1−x)Fe2O4] dendrites embedded in a MgO matrix, as shown in Fig. 1. spatial resolution of X-ray microanalysis at conventional accelerating voltages is insufficient for the quantitative analysis of these dendrites, which have widths of the order of a few hundred nanometers, without deconvolution of contributions from the MgO matrix. However, Monte Carlo simulations indicate that the interaction volume for MgFe2O4 is ∼150 nm at 3 kV accelerating voltage and therefore sufficient to analyze the dendrites without matrix contributions.Single-crystal {001}-oriented MgO was reacted with hematite (Fe2O3) powder for 6 h at 1450°C in air and furnace cooled. The specimen was then cleaved to expose a clean cross-section suitable for microanalysis.

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