scholarly journals The Role of Surface Hydrophobicity on the Structure and Dynamics of CO2 and CH4 Confined in Silica Nanopores

2021 ◽  
Vol 3 ◽  
Author(s):  
Sohaib Mohammed ◽  
Ajay Krishna Sunkara ◽  
Casey Elizabeth Walike ◽  
Greeshma Gadikota
Keyword(s):  
Electrostatic Interactions ◽  
Pore Diameter ◽  
Van Der Waals ◽  
Md Simulations ◽  
Surface Hydrophobicity ◽  
Van Der Waals Interactions ◽  
Structure And Dynamics ◽  
Transport Behavior ◽  
Subsurface Environments ◽  
Geological Formation

Advancing a portfolio of technologies that range from the storage of excess renewable natural gas for distributed use to the capture and storage of CO2 in geological formation are essential for meeting our energy needs while responding to challenges associated with climate change. Delineating the surface interactions and the organization of these gases in nanoporous environments is one of the less explored approaches to ground advances in novel materials for gas storage or predict the fate of stored gases in subsurface environments. To this end, the molecular scale interactions underlying the organization and transport behavior of CO2 and CH4 molecules in silica nanopores need to be investigated. To probe the influence of hydrophobic surfaces, a series of classical molecular dynamics (MD) simulations are performed to investigate the structure and dynamics of CO2 and CH4 confined in OH-terminated and CH3-terminated silica pores with diameters of 2, 4, 6, 8, and 10 nm at 298 K and 10 MPa. Higher adsorption extents of CO2 compared to CH4 are noted on OH-terminated and CH3-terminated pores. The adsorbed extents increase with the pore diameter. Further, the interfacial CO2 and CH4 molecules reside closer to the surface of OH-terminated pores compared to CH3-terminated pores. The lower adsorption extents of CH4 on OH-terminated and CH3-terminated pores result in higher diffusion coefficients compared to CO2 molecules. The diffusivities of both gases in OH-terminated and CH3-terminated pores increase systematically with the pore diameter. The higher adsorption extents of CO2 on OH-terminated and CH3-terminated pores are driven by higher van der Waals and electrostatic interactions with the pore surfaces, while CH4 adsorption is mainly due to van der Waals interactions with the pore walls. These findings provide the interfacial chemical basis underlying the organization and transport behavior of pressurized CO2 and CH4 gases in confinement.

Polymorphism of Trimeric Perfluoro-ortho-phenylene Mercury, [Hg(o-C6F4)]3

2004 ◽  
Vol 59 (11-12) ◽  
pp. 1483-1487 ◽  
Author(s):  
Mason R. Haneline ◽  
François P. Gabbaï
Keyword(s):  
Single Crystal ◽  
Electrostatic Interactions ◽  
Van Der Waals ◽  
Relativistic Effects ◽  
Van Der Waals Interactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Π Interactions

Three new modifications of trimeric perfluoro-ortho-phenylene mercury (2) have been investigated by single crystal X-ray diffraction. In each of these modifications, the molecules of 2 form extended stacks. Within each stack, the successive molecules are parallel and separated by approximately 3.3 - 3.4 Å. The packing observed in the different structures is rationalized on the basis of secondary mercury-π interactions, mercuriophilic interactions and electrostatic interactions. Altogether, little preference is given for one particular type of interaction. The packing appears to be dominated by non-directional van der Waals interactions between molecules of 2 which are largely aromatic and whose overall polarizability is magnified by relativistic effects at the mercury(II) centers.

Publisher's Note: “Density, structure, and dynamics of water: The effect of van der Waals interactions” [J. Chem. Phys. 134, 024516 (2011)]

2011 ◽  
Vol 134 (5) ◽  
pp. 059901 ◽  
Author(s):  
Jue Wang ◽  
G. Román-Pérez ◽  
Jose M. Soler ◽  
Emilio Artacho ◽  
M.-V. Fernández-Serra
Keyword(s):  
Van Der Waals ◽  
Chem Phys ◽  
Van Der Waals Interactions ◽  
Density Structure ◽  
Structure And Dynamics

scholarly journals How electrostatic and non-electrostatic interactions play a role in water wettability of possible nanostructure surfaces

2020 ◽  
Vol 10 (1) ◽  
pp. 69-74
Author(s):  
Nima Novin ◽  
Abolghasem Shameli ◽  
Ebrahim Balali ◽  
Shahab Zomorodbakhsh
Keyword(s):  
Molybdenum Disulfide ◽  
Electrostatic Interactions ◽  
Van Der Waals ◽  
Van Der Waals Interactions ◽  
Water Density ◽  
Density Peak ◽  
Water Contact ◽  
Water Wettability ◽  
Nanostructure Surface

Abstract The present paper investigated the effects of the electrostatic and non-electrostatic interactions on the water wettability of a surface. Based on this aim, examinations are performed on the molybdenum disulfide (MoS2) as possible nanostructure surface. The results obtained through calculating the water contact angle on the MoS2 surface indicate which this surface is a weak hydrophobic substrate. The present simulations illustrate that the electrostatic interactions have little impact on the wettability amount of the MoS2 substrate. However, the molybdenum disulfide is composed of two charged parts with significant values. In addition, it is observed that the relation between density, van der Waals and electrostatic interactions is different from each other. It have been observed that the van der Waals interactions have direct relationship with water density while there is not anything between the electrostatic interactions and water density peak. The Obtained results via simulation demonstrate that the effectiveness of electrostatic interactions on the wettability depends on the sigma in the Lennard–Jones equation. In the other words, the role of electrostatic and van der Waals interactions on the wettability are not indissociable from each other and this method is sufficient in nanostructure systems. Graphic abstract

scholarly journals Density, structure, and dynamics of water: The effect of van der Waals interactions

2011 ◽  
Vol 134 (2) ◽  
pp. 024516 ◽  
Author(s):  
Jue Wang ◽  
G. Román-Pérez ◽  
Jose M. Soler ◽  
Emilio Artacho ◽  
M.-V. Fernández-Serra
Keyword(s):  
Van Der Waals ◽  
Van Der Waals Interactions ◽  
Density Structure ◽  
Structure And Dynamics

Physical Origins of Surface Forces

2019 ◽  
pp. 181-233
Author(s):  
C. Mathew Mate ◽  
Robert W. Carpick
Keyword(s):  
Electrostatic Interactions ◽  
Van Der Waals ◽  
Aqueous Media ◽  
Atomic Level ◽  
Van Der Waals Interactions ◽  
Interaction Forces ◽  
Atoms And Molecules ◽  
Hamaker Constants ◽  
Solvation Forces ◽  
Hydrophobic Attraction

The energies and forces between contacting surfaces originate from the interaction forces between atoms and molecules. This chapter discusses how these atomic level forces lead to various types of force–separation relations as two surfaces are brought into contact. This chapter covers the interactions between atoms (repulsive atomic potentials and van der Waals interactions), the interactions within liquid and aqueous media (solvation forces, electrostatic double layer, hydration repulsion, hydrophobic attraction), and electrostatic interactions from contact electrification. Due to their ubiquitous effect on adhesion, van der Waals interactions are discussed at length, including examples for calculating adhesive forces in different geometries using Hamaker constants.

scholarly journals Changes in the Local Conformational States Caused by Simple Na+ and K+ Ions in Polyelectrolyte Simulations: Comparison of Seven Force Fields with and without NBFIX and ECC Corrections

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 252
Author(s):  
Natalia Lukasheva ◽  
Dmitry Tolmachev ◽  
Hector Martinez-Seara ◽  
Mikko Karttunen
Keyword(s):  
Experimental Data ◽  
Electrostatic Interactions ◽  
Force Fields ◽  
Dynamic Properties ◽  
Water Solution ◽  
Md Simulations ◽  
Side Chain ◽  
Local Structures ◽  
Structure And Dynamics ◽  
Molecular Sizes

Electrostatic interactions have a determining role in the conformational and dynamic behavior of polyelectrolyte molecules. In this study, anionic polyelectrolyte molecules, poly(glutamic acid) (PGA) and poly(aspartic acid) (PASA), in a water solution with the most commonly used K+ or Na+ counterions, were investigated using atomistic molecular dynamics (MD) simulations. We performed a comparison of seven popular force fields, namely AMBER99SB-ILDN, AMBER14SB, AMBER-FB15, CHARMM22*, CHARMM27, CHARMM36m and OPLS-AA/L, both with their native parameters and using two common corrections for overbinding of ions, the non-bonded fix (NBFIX), and electronic continuum corrections (ECC). These corrections were originally introduced to correct for the often-reported problem concerning the overbinding of ions to the charged groups of polyelectrolytes. In this work, a comparison of the simulation results with existing experimental data revealed several differences between the investigated force fields. The data from these simulations and comparisons with previous experimental data were then used to determine the limitations and strengths of these force fields in the context of the structural and dynamic properties of anionic polyamino acids. Physical properties, such as molecular sizes, local structure, and dynamics, were studied using two types of common counterions, namely potassium and sodium. The results show that, in some cases, both the macroion size and dynamics depend strongly on the models (parameters) for the counterions due to strong overbinding of the ions and charged side chain groups. The local structures and dynamics are more sensitive to dihedral angle parameterization, resulting in a preference for defined monomer conformations and the type of correction used. We also provide recommendations based on the results.

scholarly journals Some Energy Issues for a Nanoscale Electrostatic Potential Well in Saline Solutions

Chemosensors ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 50
Author(s):  
Jingkun Guo ◽  
Zijin Lei ◽  
Fan Wang ◽  
Jingjing Xu ◽  
Shengyong Xu
Keyword(s):  
Electrostatic Potential ◽  
Electrostatic Interactions ◽  
Saline Solution ◽  
Van Der Waals ◽  
Van Der Waals Interactions ◽  
Electrostatic Energy ◽  
Potential Well ◽  
Ionic Solution ◽  
Trapping Performance ◽  
Saline Solutions

An electrostatic potential well may be applied to trap and manipulate charged micro- and nanoparticles. An electrostatic potential well obtained from a certain charge distribution may be used to mimic the electrostatic interactions among biomolecules in live biosystems. In this study, we present a simulation study on the trapping performance of dipole clusters, which are arranged in 10 nm-sized, pentagon-shaped structures in a saline solution. The influence of electrostatic energy, entropy, and van der Waals interaction on the trapping performance of these nanostructures is then systematically calculated. The results show that the electrostatic potential well system demonstrated a moderate trapping capability, which could be enhanced using van der Waals interactions. The entropy significantly contributes to the trapping capability. This study offers some ideas for developing practical biomimetic electrostatic tweezers and nanorobots working in an ionic solution.

scholarly journals Changes in the Local Conformational States Caused by Simple Na+ and K+ Ions in Polyelectrolyte Simulations: Comparison of Seven Force Fields With and Without NBFIX and ECC Corrections

2021 ◽  
Author(s):  
Natalia Lukasheva ◽  
Dmitry Tolmachev ◽  
Hector Martinez-Seara ◽  
Mikko Karttunen
Keyword(s):  
Molecular Dynamics ◽  
Local Structure ◽  
Electrostatic Interactions ◽  
Force Fields ◽  
Water Solution ◽  
Md Simulations ◽  
Side Chain ◽  
Local Structures ◽  
Structure And Dynamics ◽  
Molecular Sizes

Electrostatic interactions have a determining role in conformational and dynamic behavior of polyelectrolyte molecules [1]. In this study, anionic polyelectrolyte molecules, poly(glutamic acid) (PGA) and poly(aspartic acid) (PASA), in water solution with the most commonly used K+ or Na+ counterions were investigated using atomistic molecular dynamics (MD) simulations. Seven common force fields, AMBER99SB-ILDN, AMBER14SB, AMBER-FB15, CHARMM22*, CHARMM27, CHARMM36m and OPLS-AA/L, both with their native parameters and with the non-bonded fix (NBFIX) and electronic continuum corrections (ECC) to were studied. These corrections have bene introduced to correct for the problem of overbinding of ions to the charged groups of polyelectrolytes. Physical properties, such as molecular sizes, local structure and dynamics, were studied using two types of common counterions, potassium and sodium. The results show that in some cases, the macroion size and dynamics depend strongly on the models (parameters) for the counterions due to strong overbinding of ions and charged side chain groups. The local structures and dynamics are more sensitive on dihedral angle parameterization resulting in a preference for defined monomer conformations amd the type of correction used.

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