Mechanistic Understanding of the Effect of Temperature and Salinity on the Water/Toluene Interfacial Tension

Jian, Cuiying; Poopari, Mohammad Reza; Liu, Qingxia; Zerpa, Nestor; Zeng, Hongbo; Tang, Tian

doi:10.1021/acs.energyfuels.6b01995

Cited by 36 publications

(47 citation statements)

References 68 publications

(136 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The linearity relationship with temperature agrees with those compiled and obtained by Vargaftik et al [51] and Schmidt and Schneider [19]. Jian et al [52] calculated the numbers of hydrogen bonds formed by water molecules at different temperatures and observed a decrease in hydrogen bonds per water molecule with increasing temperature. This explains the lower surface tension with increasing temperature observed in our study, and the same effect may occur in natural seawater.…”

Section: Surface Tensionsupporting

confidence: 87%

Effects of Natural and Artificial Surfactants on Diffusive Boundary Dynamics and Oxygen Exchanges across the Air–Water Interface

Adenaya

Haack

Stolle

et al. 2021

Oceans

View full text Add to dashboard Cite

Comparing measurements of the natural sea surface microlayer (SML) and artificial surface films made of Triton-X-100 and oleyl alcohol can provide a fundamental understanding of diffusive gas fluxes across the air–water boundary layers less than 1 mm thick. We investigated the impacts of artificial films on the concentration gradients and diffusion of oxygen (O2) across the SML, the thickness of the diffusive boundary layer (DBL), and the surface tension levels of natural seawater and deionized water. Natural and artificial films led to approximately 78 and 81% reductions in O2 concentration across the surfaces of natural seawater and deionized water, respectively. The thicknesses of the DBL were 500 and 350 µm when natural SML was added on filtered and unfiltered natural seawater, respectively, although the DBL on filtered seawater was unstable, as indicated by decreasing thickness over time. Triton-X-100 and oleyl alcohol at a concentration of 2000 µg L−1 in deionized water persistently increased the DBL thickness values by 30 and 26% over a period of 120 min. At the same concentration, Triton-X-100 and oleyl alcohol decreased the surface tension of deionized water from ~72 mN m−1 to 48 and 38 mN m−1, respectively; 47% recovery was recorded after 30 min with Triton-X-100, although low surface tension persisted for 120 min with oleyl alcohol. The critical micelle concentration values of Triton-X-100 ranged between 400 and 459 µg L−1. We, therefore, suggest that Triton-X-100 resembles natural SML because the reduction and partial recovery of the surface tension of deionized water with the surfactant resembles the behavior observed for natural slicks. Temperature and salinity were observed to linearly decrease the surface tension levels of natural seawater, artificial seawater, and deionized water. Although several factors leading to O2 production and consumption in situ are excluded, experiments carried out under laboratory-controlled conditions are useful for visualizing fine-scale processes of O2 transfer from water bodies through the surface microlayer.

show abstract

Section: Surface Tensionsupporting

confidence: 87%

Effects of Natural and Artificial Surfactants on Diffusive Boundary Dynamics and Oxygen Exchanges across the Air–Water Interface

Adenaya

Haack

Stolle

et al. 2021

Oceans

View full text Add to dashboard Cite

show abstract

“…16,17 Therefore, knowledge about the oil−brine IFT as well as other interfacial properties is of great importance in the optimization of oil production and oil−brine separation. 1,2,4,18 A large number of experimental 19−27 and modeling 1,28−40 works have been reported on the interfacial properties between oil and neat water over wide range of temperature and pressure. While these works are informative, they can only provide limited information about oil−brine interfaces, since the effect of salt ions in brine is non-negligible.…”

Section: Introductionmentioning

confidence: 99%

Effects of Salinity and N-, S-, and O-Bearing Polar Components on Light Oil–Brine Interfacial Properties from Molecular Perspectives

Nan

Wen

et al. 2019

J. Phys. Chem. C

View full text Add to dashboard Cite

Oil–brine interfaces play an important role in oil recovery and oil–brine separation, in which the effects of salinity on interfacial tension (IFT) have been much of debate in the past in experiments and modeling studies owing to complex oil compositions. In this work, we use molecular dynamics (MD) simulations to study the oil–brine interfacial properties by designing seven systems containing different oil compositions (decane with/without polar compounds) and the salinity in brine of up to ∼14 wt %. We carefully investigate the salinity and polar component effects by analyzing IFTs, density profiles, orientation parameters, hydrogen bond densities, and charge density profiles. The results indicate that O-bearing compounds (phenol and decanoic acid) can significantly reduce the oil–brine IFT and exhibit the highest Gibbs surface excess relative to water, while the others, including N-bearing compounds (pyridine and quinoline) and S-bearing compounds (thiophene and benzothiophene), only slightly decrease the oil–brine IFTs and show a relatively small Gibbs surface excess. Increasing salinity can slightly increase the oil–brine IFT except in the system containing phenol, which shows a decrease. Phenol and decanoic acid incline to be perpendicular to the interface and generate numerous hydrogen bonds with water in the interfacial region, while others prefer to be parallel to the interface with much fewer hydrogen bonds with water. On the other hand, salinity has an insignificant effect on the orientation of polar molecules and hydrogen bond density in the interfacial region. The charges at the interfaces on the brine and oil sides are negative and positive, respectively, and the polar compounds disturb the arrangement of water molecules in the interfacial regions, while the addition of salt ions result in the higher peak values of charges in terms of water and system. Our study should provide new insights into the oil–brine interfacial issues and clarify some unsettled disputes.

show abstract

“…Water molecules were described by the well-tested simple-point charge (SPC) model . Previous simulations using the obtained topologies have predicted properties consistent with experimental studies, − , for example, bulk density of toluene, toluene/water interfacial tension (IFT) and how it is affected by temperature, salinity and the presence of VO-79, − and the formation of the GO–humic acid sandwich complex, to name a few.…”

Section: Methodsmentioning

confidence: 63%

“…Violanthrone-79 (VO-79, C 50 H 48 O 4 ) was chosen as the model for asphaltene. VO-79 has one central polyaromatic core (PAC) and two side chains, resembling the island-type structure of asphaltene proposed in the literature and has been employed widely to study the behavior of asphaltenes at the oil/water interface. − The model for GO (C 106 H 26 O 20 ) was based on experimental characterizations and simulations in previous studies. , All the carboxyl and hydroxyl groups have net zero charge to mimick an acidic environment, where GO has been shown to be effective in demulsification . Molecular structures of VO-79 and GO are shown in Figure .…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Molecular Dynamics Study on the Mechanism of Graphene Oxide to Destabilize Oil/Water Emulsion

2019

Self Cite

View full text Add to dashboard Cite

Previous experiments have demonstrated the capability of graphene oxide (GO) to destabilize oil-in-water (O/W) and water-in-oil (W/O) emulsions, although there are debates on the underlying mechanism. Using molecular dynamics simulations, this work targets an atomistic-level understanding of the mechanism for GO to destabilize O/W and W/O emulsions in the presence of violanthrone-79 (VO-79), a model compound for asphaltene. For both types of emulsions, a GO/VO-79 binary film is formed on the oil/water interface, which can stabilize VO-79 on the interface. Detailed structural analysis shows that the majority of GO in the binary film is parallel to the interface and cause VO-79 to align with them, changing the original interface morphology. The results favor the mechanism that GO destabilizes W/O or O/W emulsions by first forming a film around the emulsion droplets and then enhancing the adhesion between droplets, or between a droplet and the macroscopic oil/water interface, through film–film interactions. Additional interfacial tension (IFT) calculations confirm that GO can increase the toluene/water IFT in the presence of VO-79, which is beneficial for emulsion destabilization.

show abstract

Mechanistic Understanding of the Effect of Temperature and Salinity on the Water/Toluene Interfacial Tension

Cited by 36 publications

References 68 publications

Effects of Natural and Artificial Surfactants on Diffusive Boundary Dynamics and Oxygen Exchanges across the Air–Water Interface

Effects of Natural and Artificial Surfactants on Diffusive Boundary Dynamics and Oxygen Exchanges across the Air–Water Interface

Effects of Salinity and N-, S-, and O-Bearing Polar Components on Light Oil–Brine Interfacial Properties from Molecular Perspectives

Molecular Dynamics Study on the Mechanism of Graphene Oxide to Destabilize Oil/Water Emulsion

Contact Info

Product

Resources

About