Pattern Formation in Colloidal Monolayers at the Air–Water Interface

Ghezzi, Fabio; Earnshaw, J. C.; Finnis, Michael W.; McCluney, M.

doi:10.1006/jcis.2001.7495

Cited by 89 publications

(114 citation statements)

References 26 publications

(25 reference statements)

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“…First, the simulations at high densities and low temperatures require a very large number of MC cycles in order to reach equilibrated states. Near the transtition points the number of cycles required to define the phase transition was on the order of 10 6 . In the case of the isotherms T* ) 0.5 and T* ) 0.8, metastable states can be present around the most noticeable phase transition at low surface pressures.…”

Section: Resultsmentioning

confidence: 99%

“…[5][6][7]9,10 The formation of these patterns cannot be explained solely on the basis of repulsive interactions. We have recently measured the pair interaction potential at low particle surface density, 11 and indeed the potential shows a secondary minimum in the micrometer range, similar to those found in colloidal systems trapped between glass plates.…”

Section: Introductionmentioning

confidence: 99%

“…This unexpected attraction has been observed in systems of latex spheres trapped between glass plates 4 or at fluid-fluid interfaces. [5][6][7][8] For colloidal systems trapped between glass plates, the particles repel each other electrostatically through a Yukawatype potential. If the separation of the walls is small enough to restrict the movement of the particles to a plane, a secondary minimum in the micrometer range of the pair interaction potential is formed.…”

Section: Introductionmentioning

confidence: 99%

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Predicting the Phase Diagram of Two-Dimensional Colloidal Systems with Long-Range Interactions

2006

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The phase diagram of a two-dimensional model system for colloidal particles at the air-water interface was determined using Monte Carlo computer simulations in the isothermic-isobaric ensemble. The micrometerrange binary colloidal interaction has been modeled by hard disklike particles interacting via a secondary minimum followed by a weaker longer-range repulsive maximum, both of the order of k B T. The repulsive part of the potential drives the clustering of particles at low densities and low temperatures. Pinned voids are formed at higher densities and intermediate values of the surface pressure. The analysis of isotherms, translational and orientational correlation functions as well as structure factor gives clear evidence of the presence of a melting first-order transition. However, the melting process can be also followed by a metastable route through a hexatic phase at low surface pressures and low temperatures, before crystalization occurs at higher surface pressure.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Predicting the Phase Diagram of Two-Dimensional Colloidal Systems with Long-Range Interactions

2006

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“…A reduction in IFT may be caused by the attachment of SiO 2 NPs at the oil-aqueous interface. The hydrophobic and hydrophilic nature of the SiO 2 NPs causes a manifestation of this attachment (Ghezzi et al 2001;Schwartz et al 2001).…”

Section: Raspberry-like Morphology Of Sio 2 Nanoparticlesmentioning

confidence: 99%

Effects of silica-based nanostructures with raspberry-like morphology and surfactant on the interfacial behavior of light, medium, and heavy crude oils at oil-aqueous interfaces

Bai

Korte

et al. 2017

Appl Nanosci

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Any efficient exploitation of new petroleum reservoirs necessitates developing methods to mobilize the crude oils from such reservoirs. Here silicon dioxide nanoparticles (SiO 2 NPs) were used to improve the efficiency of the chemical-enhanced oil recovery process that uses surfactant flooding. Specifically, SiO 2 NPs (i.e., 0, 0.001, 0.005, 0.01, 0.05, and 0.1 wt%) and Tween Ò 20, a nonionic surfactant, at 0, 0.5, and 2 critical micelle concentration (CMC) were varied to determine their effect on the stability of nanofluids and the interfacial tension (IFT) at the oil-aqueous interface for 5 wt% brine-surfactantSiO 2 nanofluid-oil systems for West Texas Intermediate light crude oil, Prudhoe Bay medium crude oil, and Lloydminster heavy crude oil. Our study demonstrates that SiO 2 NPs may either decrease, increase the IFT of the brinesurfactant-oil systems, or exhibit no effects at all. For the brine-surfactant-oil systems, the constituents of the oil and aqueous substances affected the IFT behavior, with the nanoparticles causing a contrast in IFT trends according to the type of crude oil. For the light oil system (0.5 and 2 CMC Tween threshold concentration resulted in a decrease in IFT, and concentrations above this threshold resulted in an increase in IFT. The IFT decreased until the NP concentration reached a threshold concentration where synergetic effects between nonionic surfactants and SiO 2 NPs are the opposite and result in antagonistic effects. Adsorption of both SiO 2 NPs and surfactants at an interface caused a synergistic effect and an increased reduction in IFT. The effectiveness of the brine-surfactant-SiO 2 nanofluids in decreasing the IFT between the oil-aqueous phase for the three tested crude oils were ranked as follows: (1) Prudhoe Bay [ (2) Lloydminster [ and (3) West Texas Intermediate. The level of asphaltenes and resins in these crude oil samples reflected these rankings. A decrease in the IFT also indicated the potential of the SiO 2 NPs to decrease capillary pressure and induce the movement and recovery of oil in original water-wet reservoirs. Conversely, an increase in IFT indicated the potential of SiO 2 NPs to increase capillary pressure and oil recovery in reservoirs subject to wettability reversal under water-wet conditions. Raspberrylike morphology particles were discovered in 5 wt% brinesurfactant-SiO 2 nanofluid-oil systems. The development of raspberry-like particles material with high surface area, high salt stability, and high capability of interfaces alteration and therefore wettability changes offers a wide range of applications in the fields of applied nanoscience, environmental engineering, and petroleum engineering.

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“…The structural rearrangements and observations of order-disorder transitions in colloidal systems have been reported in a number of theoretical and experimental works on ionic colloidal dispersions/suspensions [19][20][21][22][23][24][25][26][27][28]. Far less attention though has been given to the study of monolayers of colloid spheres [16,[35][36][37][38][39][40][41][42]. Yet, the latter are technologically very important as templates for large-area patterning applications [6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Macroscopic Ordering of Polystyrene Carboxylate-Modified Nanospheres Self-Assembled at the Water−Air Interface

2010

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RECEIVED DATE (to be automatically inserted after your manuscript is accepted if required according to the journal that you are submitting your paper to)In this work we present results from an experimental study of ordering characteristics in monolayers of polystyrene nanospheres self-assembled at a water-air interface. We demonstrate that the interaction of spheres, governed by the dissemination of surface charge, leads to the formation of macroscopic closepacked ordered areas or 'domains' with a well defined orientation of the lattice axes over areas of 25 mm². It was found that by changing the surface chemistry of the spheres it is possible to modify the balance between the attractive and repulsive forces and thus to control the ordering characteristics. We implemented a model which simulates the process of self-assembly and examines the ordering characteristics for layers with different ratio between attractive and repulsive forces. A good qualitative agreement was found between the simulations and experiment. These studies are technologically relevant as a method of producing nanosphere templates for large area patterned materials.2

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Pattern Formation in Colloidal Monolayers at the Air–Water Interface

Cited by 89 publications

References 26 publications

Predicting the Phase Diagram of Two-Dimensional Colloidal Systems with Long-Range Interactions

Predicting the Phase Diagram of Two-Dimensional Colloidal Systems with Long-Range Interactions

Effects of silica-based nanostructures with raspberry-like morphology and surfactant on the interfacial behavior of light, medium, and heavy crude oils at oil-aqueous interfaces

Macroscopic Ordering of Polystyrene Carboxylate-Modified Nanospheres Self-Assembled at the Water−Air Interface

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