scholarly journals Self-Assembly of NaOL-DDA Mixtures in Aqueous Solution: A Molecular Dynamics Simulation Study

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7117
Author(s):  
Li Wang ◽  
Rui Xu ◽  
Ruohua Liu ◽  
Peng Ge ◽  
Wei Sun ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Aqueous Solution ◽  
Self Assembly ◽  
Electrostatic Interactions ◽  
Large Scale ◽  
Dynamics Simulation ◽  
Solvent Accessible Surface Area ◽  
Molar Ratio ◽  
Mixed System ◽  
Mixed Systems

The self-assembly behaviors of sodium oleate (NaOL), dodecylamine (DDA), and their mixtures in aqueous solution were systematically investigated by large-scale molecular dynamics simulations, respectively. The interaction mechanisms between the surfactants, as well as the surfactants and solvent, were revealed via the radial distribution function (RDF), cluster size, solvent-accessible surface area (SASA), hydrogen bond, and non-bond interaction energy. Results showed that the molecules more easily formed aggregates in mixed systems compared to pure systems, indicating higher surface activity. The SASA values of DDA and NaOL decreased significantly after mixing, indicating a tighter aggregation of the mixed surfactants. The RDF results indicated that DDA and NaOL strongly interacted with each other, especially in the mixed system with a 1:1 molar ratio. Compared to van der Waals interactions, electrostatic interactions between the surfactant molecules were the main contributors to the improved aggregation in the mixed systems. Besides, hydrogen bonds were found between NaOL and DDA in the mixed systems. Therefore, the aggregates in the mixed systems were much more compact in comparison with pure systems, which contributed to the reduction of the repulsive force between same molecules. These findings indicated that the mixed NaOL/DDA surfactants had a great potential in application of mineral flotation.

scholarly journals Atomistic simulation studies of ionic cyanine dyes: self-assembly and aggregate formation in aqueous solution

2021 ◽  
Author(s):  
Gary Yu ◽  
Martin Walker ◽  
Mark Richard Wilson
Keyword(s):  
Molecular Dynamics ◽  
Aqueous Solution ◽  
Liquid Crystals ◽  
Self Assembly ◽  
Atomistic Simulation ◽  
Large Scale ◽  
Cyanine Dyes ◽  
Simulation Studies ◽  
Aggregate Formation ◽  
Dynamics Simulations

Cyanine dyes are known to form large-scale aggregates of various morphologies via spontaneous self-assembly in aqueous solution, akin to chromonic liquid crystals. Atomistic molecular dynamics simulations have been performed on...

Large scale atomistic simulation of single-layer graphene growth on Ni(111) surface: molecular dynamics simulation based on a new generation of carbon–metal potential

Nanoscale ◽  
2016 ◽  
Vol 8 (2) ◽  
pp. 921-929 ◽  
Author(s):  
Ziwei Xu ◽  
Tianying Yan ◽  
Guiwu Liu ◽  
Guanjun Qiao ◽  
Feng Ding
Keyword(s):  
Molecular Dynamics ◽  
Self Assembly ◽  
Large Scale ◽  
Md Simulation ◽  
Single Layer ◽  
Dynamics Simulation ◽  
Single Layer Graphene ◽  
Simulation Based ◽  
Bond Order Potential ◽  
New Generation

A molecular dynamics (MD) simulation of carbon atom self-assembly on a Ni(111) surface based on a well-designed empirical reactive bond order potential and atomistic details.

scholarly journals Investigation of the Interaction of Drug Tetradecyltrimethylammonium Bromide with Cetyltrimethylammonium Bromide at Different Temperature

2020 ◽  
pp. 15-24
Author(s):  
Md. Matiar Rahman ◽  
Salina Rahman ◽  
Nasiruddin .
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Critical Micelle Concentration ◽  
Hydrophobic Interaction ◽  
Electrostatic Interactions ◽  
Cetyltrimethylammonium Bromide ◽  
Dynamics Simulation ◽  
Tetradecyltrimethylammonium Bromide ◽  
Transfer Energy ◽  
Mixed Systems

Antibiotic interaction between tetradecyltrimethylammonium bromide (TTAB) with cetyltrimethylammonium bromide (CTAB) has been studied in solution and within the attendance of salts at several temperatures (298.15, 303.15, 308.15, 313.15 and 318.15 K). One critical micelle concentration (CMC) was noted for pure CTAB and their mixture with the drug tetradecyltrimethylammonium bromide (TTAB). The CMC values for mixed systems (TTAB + CTAB) within the presence of salt exhibited lower in magnitude as compared to their absence. This acknowledged the first micellization of the mixture of TTAB and CTAB. All the G0m values were found to be negative for all systems. The H0m and S0m values disclosed that hydrophobic and electrostatic interactions were increased within the presence of salts compared to their absence at lower and better temperatures respectively. The opposite thermodynamics parameters like transfer energy (G0m.tr.), transfer enthalpy (H0m.tr.) also as transfer entropy (S0m.tr.) were also determined and discussed intimately. The inherent enthalpy gain (H0m) and therefore the compensation temperature (Tc) were also estimated and deliberated. Molecular dynamics simulation exposes that aqueous also as salt environment have an impact on the hydrophobic interaction between tetradecyltrimethylammonium bromide (TTAB) with cetyltrimethylammonium bromide (CTAB).

Combustion Driven by Fragment-based Ab Initio Molecular Dynamics Simulation

2019 ◽  
Author(s):  
Liqun Cao ◽  
Jinzhe Zeng ◽  
Mingyuan Xu ◽  
Chih-Hao Chin ◽  
Tong Zhu ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Large Scale ◽  
Methane Combustion ◽  
Combustion Method ◽  
Dynamics Simulation ◽  
Ab Initio Molecular Dynamics ◽  
Computational Time ◽  
Combustion Mechanism ◽  
Daily Lives

Combustion is a kind of important reaction that affects people's daily lives and the development of aerospace. Exploring the reaction mechanism contributes to the understanding of combustion and the more efficient use of fuels. Ab initio quantum mechanical (QM) calculation is precise but limited by its computational time for large-scale systems. In order to carry out reactive molecular dynamics (MD) simulation for combustion accurately and quickly, we develop the MFCC-combustion method in this study, which calculates the interaction between atoms using QM method at the level of MN15/6-31G(d). Each molecule in systems is treated as a fragment, and when the distance between any two atoms in different molecules is greater than 3.5 Å, a new fragment involved two molecules is produced in order to consider the two-body interaction. The deviations of MFCC-combustion from full system calculations are within a few kcal/mol, and the result clearly shows that the calculated energies of the different systems using MFCC-combustion are close to converging after the distance thresholds are larger than 3.5 Å for the two-body QM interactions. The methane combustion was studied with the MFCC-combustion method to explore the combustion mechanism of the methane-oxygen system.

Sputtering of Graphite by Hydrogen Isotopes in the Fusion Environment: A Molecular Dynamics Simulation Study

2018 ◽  
Vol 4 (4) ◽  
Author(s):  
Qiang Zhao ◽  
Yang Li ◽  
Zheng Zhang ◽  
Xiaoping Ouyang
Keyword(s):  
Molecular Dynamics ◽  
Incident Energy ◽  
Large Scale ◽  
Incident Angle ◽  
Hydrogen Isotopes ◽  
Dynamics Simulation ◽  
Calculation Results ◽  
Sputtering Yield ◽  
Increasing Temperature ◽  
Sputtering Yields

The sputtering of graphite due to the bombardment of hydrogen isotopes is crucial to successfully using graphite in the fusion environment. In this work, we use molecular dynamics to simulate the sputtering using the large-scale atomic/molecular massively parallel simulator (lammps). The calculation results show that the peak values of the sputtering yield are between 25 eV and 50 eV. When the incident energy is greater than the energy corresponding to the peak value, a lower carbon sputtering yield is obtained. The temperature that is most likely to sputter is approximately 800 K for hydrogen, deuterium, and tritium. Below the 800 K, the sputtering yields increase with temperature. By contrast, above the 800 K, the yields decrease with increasing temperature. Under the same temperature and incident energy, the sputtering rate of tritium is greater than that of deuterium, which in turn is greater than that of hydrogen. When the incident energy is 25 eV, the sputtering yield at 300 K increases below an incident angle at 30 deg and remains steady after that.

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