Asphaltene Adsorption on Iron Oxide Surfaces

2015 ◽  
pp. 200-221 ◽  
Keyword(s):  
Iron Oxide ◽  
Oxide Surfaces

Simulating Surface Forces Between Iron Oxide Surfaces Immersed in Methyl Oleate Using Molecular Dynamics

2018 ◽  
Author(s):  
William W. F. Chong ◽  
Hedong Zhang
Keyword(s):  
Molecular Dynamics ◽  
Iron Oxide ◽  
Methyl Oleate ◽  
Md Simulation ◽  
Surface Forces ◽  
Oxide Surfaces ◽  
Load Bearing ◽  
Multi Scale ◽  
Molecular Potentials ◽  
Solvation Forces

Using Molecular Dynamics (MD) simulation, the current study determined the surface forces between iron oxide surfaces when immersed in methyl oleate. Condensed-phase Optimized Molecular Potentials for Atomistic Simulation Studies (COMPASS) force field was used to model the methyl oleate molecules. For the nano-confinement simulation, the iron oxide wall was modelled from its crystal structure. The nano-confinement simulation model was setup in a manner where the confined methyl oleate molecules were in contact with the bulk molecules surrounding each side of the iron oxide walls. Through the simulation, the load-separation gap profile was obtained by reducing the separation gap between the ferric oxide walls. When the separation gap was reduced from 2.75 nm to 1.88 nm, the load is shown to increase monotonically. Such increase in load bearing ability of the contact is observed to correspond to a more densely packed methyl oleate molecules, reflected by four well-formed layers across the separation gap. As the gap is dropped from 1.88 nm to 1.63 nm, the load instead reduces, indicating deteriorating load bearing ability of the contact. However, the load bearing ability of the contact is then shown to recover when the gap was further reduced till 1.38 nm. This oscillatory load trend is shown to be as a result of a layer of methyl oleate molecules being squeezed out of contact, corroborated by the density profile change where four well-formed layers were reduced to only three layers from 1.88 nm to 1.38 nm gap. This also indicates that the simulated contact exhibits structural forces, known as solvation forces. Thus, the MD simulation discussed in this study is demonstrated to be capable of providing a foundation to allow for a multi-scale simulation, integrating various force laws at different length scales, to study larger scale tribological contacts.

Photodesorption of fulvic acid from iron oxide surfaces into aqueous solutions

2001 ◽  
Vol 174 (2) ◽  
pp. 167-175 ◽  
Author(s):  
Robert B. Bjorklund ◽  
Susanne Karlsson ◽  
Hans Borén ◽  
Bert Allard ◽  
Ingemar Lundström
Keyword(s):  
Iron Oxide ◽  
Aqueous Solutions ◽  
Fulvic Acid ◽  
Oxide Surfaces

Interactions of Different Redox States of Phenyl-Capped Aniline Tetramers with Iron Oxide Surfaces and Consequences for Corrosion Inhibition

2017 ◽  
Vol 164 (14) ◽  
pp. C1013-C1026 ◽  
Author(s):  
Tanzina Chowdhury ◽  
Amirmasoud Mohtasebi ◽  
Svetlana Kostina ◽  
Xiangrong Zhang ◽  
Joseph R. Kish ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Corrosion Inhibition ◽  
Oxide Surfaces ◽  
Redox States

scholarly journals Structure and reactivity of iron oxide surfaces

1999 ◽  
Vol 114 ◽  
pp. 363-380 ◽  
Author(s):  
Sh. K. Shaikhutdinov ◽  
Y. Joseph ◽  
C. Kuhrs ◽  
W. Ranke ◽  
W. Weiss
Keyword(s):  
Iron Oxide ◽  
Oxide Surfaces

The Adsorption of Perfluorooctane Sulfonate onto Sand, Clay, and Iron Oxide Surfaces

2007 ◽  
Vol 52 (4) ◽  
pp. 1165-1170 ◽  
Author(s):  
Ramona L. Johnson ◽  
Amy J. Anschutz ◽  
Jean M. Smolen ◽  
Matt F. Simcik ◽  
R. Lee Penn
Keyword(s):  
Iron Oxide ◽  
Perfluorooctane Sulfonate ◽  
Oxide Surfaces
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