Investigations of Interfacial Properties of Surfactants with Different Structures at the Oil/Water Interface Using Dissipative Particle Dynamics

Wang, Zhining; Li, Yiming; Guo, Yingyan; Zhang, Haixia

doi:10.1080/01932691.2012.731637

Cited by 8 publications

(6 citation statements)

References 40 publications

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“…The DPD method is a coarse-grained simulation method in which the random force coefficient σ = 3, and the dissipative force coefficient η = 4.5 are controlled in the simulation, allowing the simulation to run at a temperature of K B T = 1. The simulation applies periodic boundary conditions. ,,− The degree of coarse graining used in here is N m = 3. The volume of the beads is 90 Å 3 , the radius of the beads is 6.46 Å, and the mass of the beads is 54 amu. ,, The equilibrium bond length r 0 = 3 Å and a spring constant of 300 kcal (mol·Å 2 ) −1 are assigned for all the beads of aromatic rings. , The time scale τ is calculated by eq , ,, and the simulation scale τ = 3.0158 ps is calculated.…”

Section: Research Methods and Modelsmentioning

confidence: 99%

Dissipative Particle Dynamics-Based Simulation of the Effect of Asphaltene Structure on Oil–Water Interface Properties

Liang,

Liu,

Jiang

et al. 2023

ACS Omega

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Asphaltenes are the main substances that stabilize emulsions during the production, processing, and transport of crude oil. The purpose of this research is to investigate the process of asphaltenes forming interfacial films at the oil−water interface by means of dissipative particle dynamics (DPD) and the effect of asphaltenes of different structures on the oil−water interface during the formation of interfacial film. It is demonstrated that the thickness of the interfacial film formed at the oil−water interface gradually increases as the asphaltene concentration rises and the amount of asphaltene adsorbed at the oil−water interface gradually multiplies. Both the number and type of heteroatoms in asphaltenes affect the interfacial behavior of asphaltenes. The interface activity of asphaltenes can be enhanced by increasing the number of heteroatoms in the asphaltene, and the type of heteroatom affects as well the interfacial activity of the asphaltene as it affects the aggregation behavior of the asphaltene in the system. As the number of asphaltene aromatic rings increases, the oil−water interfacial tension (IFT) trends down gradually, while the effect of alkyl side chains on the reduction of IFT of asphaltenes is different, and asphaltenes with medium length alkyl side chains can reduce IFT more efficiently.

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Section: Research Methods and Modelsmentioning

confidence: 99%

Dissipative Particle Dynamics-Based Simulation of the Effect of Asphaltene Structure on Oil–Water Interface Properties

Liang,

Liu,

Jiang

et al. 2023

ACS Omega

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“…In eq , the spring constant (or the rigidity parameter), k S , controls the stiffness of the molecule, and r 0 is the spring equilibrium distance. There are various suggestions in the literature for values of k S and r 0 : , ( k S = 4 and r 0 = 0), ,,,,− ( k S = 10 and r 0 = 0.86), and ( k S = 100 and r 0 = 0.7). , As is seen by the references, the most common and reliable values among them are ( k S = 4 and r 0 = 0) that were used in our DPD simulations.…”

Section: The Modelsmentioning

confidence: 95%

“…To have an acceptable ( N , V , T ) ensemble in the DPD method, the fluctuation–dissipation relation (eq ) should be satisfied. , For SARA heavy crude oil systems, the resin and asphaltene cores were each considered as a single bead, and the rigidity of the core is not a determining factor and it is not an issue with which to be concerned . However, for all of the connected beads of the studied DPD systems, the rigidity parameter, k S , was kept as a fixed constant in the DPD unit ( k B T / r C 2 ) as k S = 4. ,− The dissipation strength was assumed as ζ = 4.5 in DPD units ( ) and the noise strength as σ = 3, to control the temperature via the fluctuation dissipation theorem (eq ). It is reported that for a typical DPD simulation of such oil/water systems, only about 5 × 10 4 steps are required to follow the beads motion to study the formation and decomposition of aggregates .…”

Section: Simulation Detailsmentioning

confidence: 99%

Self-Accumulation of Uncharged Polyaromatic Surfactants at Crude Oil–Water Interface: A Mesoscopic DPD Study

2016

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The dissipative particle dynamics (DPD) technique was applied to study the behavior of several uncharged perylene bisimide-based polyaromatic surfactant (PAS) molecules, with the same polyaromatic core but with different terminal functional types (TP, C5Pe, PAP, and PCH) at the crude oil–water interface. We considered the SARA crude oil model with Persian Gulf oil field composition, which includes saturates, 59%; aromatics, 28.5%; resins, 9.7%; and asphaltenes, 2.8% at two temperatures 298 and 363 K. The DPD interaction parameters for the bead pairs needed in the DPD simulations were evaluated by using the well-known correlation equation, where the required Flory–Huggins interaction parameter in this equation was calculated by the blend methodology model. The results indicated that the C5Pe terminal functional type of PAS is absorbed more effectively on the water droplet interface in the crude oil system and can reduce the interfacial tension (IFT) to facilitate the oil–water separation. The results of this simulation can be used to choose proper demulsifier surfactant for application in various processes in the oil industry as well as enhanced oil recovery (EOR).

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“…The parameter a ij represents the maximal repulsion between the considered particles [154]. The method of dissipative particle dynamics is successfully applied for description of the formation of surfactant and polymer micelles, vesicles, and clusters [155][156][157][158][159] and for defining the structural features and interfacial tension at the oil/ water interface with presence of surfactants [153,160]. For instance, in studies [153,161], the applicability of DPD was shown in the framework of the coarse grain model for estimation of CMC and aggregation number of nonionic surfactants (ethoxylated alcohols, taken as example).…”

Section: Mesoscale Approachesmentioning

confidence: 99%

“…The DPD method was employed in studies [155][156][157]160] delt with the estimation of the bending modulus of the water/ oil interface in the presence of surfactants with different alkyl chain length and the structure of surfactant bilayers. It gives also adequate results in simulations of transitions of vesicle shapes built by amphiphilic three-block-copolymers [164].…”

Section: Mesoscale Approachesmentioning

confidence: 99%

Theoretical description of 2D-cluster formation of nonionic surfactants at the air/water interface

2015

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Recent progress in modeling of the surfactant behavior from atomistic to continuous at the air/water interface across different space-time scales is reviewed. Advantages and disadvantages of modern quantum mechanical, molecular dynamical, and mesoscale methods are discussed for description of interactions between amphiphilic molecules leading to formation of 2D films. The use of nonempirical and semiempirical methods for assessment of the thermodynamic and structural parameters of large van der Waals complexes is of particular interest. An approach for calculation of the thermodynamic and structural parameters of clusterization for nonionic surfactants at the air/water interface is proposed on the basis of the quantum chemical semiempirical PM3 method. This approach implicitly takes into account the influence of the interface on the surfactant molecules via stretching and orienting effect. The calculations are carried out in the supermolecule approximation for a limited number of small amphiphilic aggregates with different alkyl chain. The correlation analysis of the calculated data array provides the increments contributing by the intermolecular CH···HC interactions and interactions between hydrophilic parts into the thermodynamic parameters of formation and clusterization. Obtained increments are further used for constructing the dependencies of the thermodynamic clusterization parameters per one monomer on the alkyl chain length for large clusters up to 2D films. In the framework of the proposed theoretical approach, the next parameters are calculated as follows: enthalpy, entropy, and Gibbs' energy of clusterization for 11 homologous series of nonionic surfactants, threshold chain length enabling the process of monolayer formation at standard conditions, the Btemperature effect^of clusterization, and the structural parameters of the monolayer unit cell (particularly the tilt angle) depending on the size of the hydrophilic headgroup of the amphiphilic compound.

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Investigations of Interfacial Properties of Surfactants with Different Structures at the Oil/Water Interface Using Dissipative Particle Dynamics

Cited by 8 publications

References 40 publications

Dissipative Particle Dynamics-Based Simulation of the Effect of Asphaltene Structure on Oil–Water Interface Properties

Dissipative Particle Dynamics-Based Simulation of the Effect of Asphaltene Structure on Oil–Water Interface Properties

Self-Accumulation of Uncharged Polyaromatic Surfactants at Crude Oil–Water Interface: A Mesoscopic DPD Study

Theoretical description of 2D-cluster formation of nonionic surfactants at the air/water interface

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