scholarly journals In-Situ Continuous Monitoring of the Viscosity of Surfactant-Stabilized and Nanoparticles-Stabilized Pickering Emulsions

2019 ◽  
Vol 9 (19) ◽  
pp. 4044 ◽  
Author(s):  
Upinder Bains ◽  
Rajinder Pal
Keyword(s):  
Volume Fraction ◽  
Dispersed Phase ◽  
Pickering Emulsions ◽  
Volume Fractions ◽  
Shear Thinning Fluids ◽  
Oil In Water ◽  
Droplet Sizes ◽  
High Concentrations ◽  
The Stability

An in-situ method of measuring the viscosity of unstable and stable emulsions on a continuous basis under agitation conditions was developed and utilized to investigate the viscous behaviour of surfactant-stabilized and nanoparticles-stabilized oil-in-water (O/W) emulsions at different volume fractions of the dispersed phase (oil). The stability characteristics (droplet size and phase-separation) of emulsions under quiescent conditions were also determined with the aging of emulsions. Emulsions are Newtonian at low volume fractions of the dispersed phase. At high concentrations of the dispersed phase, emulsions behave as non-Newtonian shear-thinning fluids. The nanoparticles-stabilized (Pickering) emulsions are unstable in comparison with the surfactant-stabilized emulsions. The droplet sizes of Pickering emulsions increase rapidly with aging, whereas the droplet sizes of surfactant-stabilized remain nearly the same over a period of 24 h. However, Pickering emulsions are much more viscous than the surfactant-stabilized emulsions when comparison is made at the same volume fraction of the dispersed phase.

scholarly journals Simulation of the Effect of Oil Volume Fractions in an Oil-Water Flows Along a Circular Pipe: A Finite Element Approach

2018 ◽  
Vol 10 (5) ◽  
pp. 19
Author(s):  
Ferdusee Akter ◽  
Md. Bhuyan ◽  
Ujjwal Deb
Keyword(s):  
Finite Element ◽  
Volume Fraction ◽  
Fluid Velocity ◽  
Galerkin Approximation ◽  
Computational Domain ◽  
Two Phase Flows ◽  
Two Phase ◽  
Volume Fractions ◽  
Oil In Water ◽  
Element Approach

Two phase flows in pipelines are very common in industries for the oil transportations. The aim of our work is to observe the effect of oil volume fraction in the oil in water two phase flows. The study has been accomplished using a computational model which is based on a Finite Element Method (FEM) named Galerkin approximation. The velocity profiles and volume fractions are performed by numerical simulations and we have considered the COMSOL Multiphysics Software version 4.2a for our simulation. The computational domain is 8m in length and 0.05m in radius. The results show that the velocity of the mixture decreases as the oil volume fraction increases. It should be noted that if we gradually increase the volume fractions of oil, the fluid velocity also changes and the saturated level of the volume fraction is 22.3%.

The Role of Excess Attractive Particles in the Elasticity of High Internal Phase Pickering Emulsions

Soft Matter ◽  
2021 ◽  
Author(s):  
Junsu Chae ◽  
Siyoung Choi ◽  
KyuHan Kim
Keyword(s):  
Volume Fraction ◽  
Dispersed Phase ◽  
Pickering Emulsions ◽  
High Internal Phase Emulsion ◽  
Internal Phase

A high internal phase emulsion (HIPE), which has a volume fraction of dispersed phase of over 74%, shows a solid like property because of concentrated polyhedral droplets. Although many studies...

scholarly journals Study of the conservation properties in two-way coupled dispersed multiphase flows using finite volume methods

2021 ◽  
Vol 2116 (1) ◽  
pp. 012071
Author(s):  
Linda Bahramian ◽  
Jordi Muela ◽  
C David Pérez-Segarra
Keyword(s):  
Carrier Phase ◽  
Multiphase Flows ◽  
Volume Fraction ◽  
Finite Volume Methods ◽  
Dispersed Phase ◽  
Volume Fractions ◽  
Large Eddy ◽  
Discrete Operators ◽  
Dispersed Phases ◽  
Dispersed Flows

Abstract In order to simulate dispersed multiphase flows, the coupling level must be determined according to the volume fraction in the system. The volume fraction is the ratio of the total volume of the dispersed phases over the total volume of the flow. In dilute flows, with volume fractions smaller than 10-6, only the influence of carrier phase over the dispersed phase is considered which is known as one-way coupling. Nonetheless, in dispersed flows with higher volume fractions, the effect of the dispersed phase over the continuous one should be taken into consideration, known as two-way coupling. This effect normally is applied as a source term in the conservation equations of the carrier phase. Depending on the numerical method and the discrete operators employed, these source terms can lead to some issues when aiming to preserve physical properties like mass, momentum and energy. Moreover, in order to validate the two-way coupling method, a particle-laden turbulent flow benchmark case with a mass loading of 22% is simulated by means of large eddy numerical simulation (LES). The aim of this work is to study the conservation properties of dispersed multiphase flows like momentum, kinetic energy and thermal energy through two-way coupling between dispersed and continuous phases.

Pickering-Type Emulsions of ODSA Sizing Agent Stabilized by Nano-Montmorillonite and N-Dodecane

2013 ◽  
Vol 319 ◽  
pp. 233-238 ◽  
Author(s):  
De Hai Yu ◽  
Zhao Yun Lin ◽  
You Ming Li
Keyword(s):  
Particle Concentration ◽  
Ph Value ◽  
Water Interface ◽  
Pickering Emulsions ◽  
Paper Sizing ◽  
Oil In Water ◽  
Effects Of Ph ◽  
Oil Water ◽  
The Stability ◽  
Hydrolysis Resistance

Octadecenylsuccinic anhydride (ODSA) is an internal sizing agent used to hydrophobize paper and paper board in the process of papermaking. Nano-montmorillonite (MMT) particles and n-dodecane were used as the stabilizer to prepare stable ODSA Pickering emulsions. The effects of pH value, particle concentration, hydrolysis resistance and paper sizing performance of the ODSA Pickering emulsions were investigated. It was found that the stability of ODSA emulsions first increased and then decreased as the pH value decreased. More stable oil-in-water (o/w) emulsion can be made using 10 vol.% n-dodecane. Particle concentration was linked to the formation of particle films at oil–water interface, with a required minimum particle concentration of 1.5 wt.%. Paper sizing degree analysis indicated that the ODSA Pickering emulsions show increased hydrolysis resistance and good sizing performance.

scholarly journals Water-in-Oil Nano-Emulsions Prepared by Spontaneous Emulsification: New Insights on the Formulation Process

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1030
Author(s):  
Salman Akram ◽  
Nicolas Anton ◽  
Ziad Omran ◽  
Thierry Vandamme
Keyword(s):  
Volume Fraction ◽  
Scale Up ◽  
Surface Modifications ◽  
Yield Potential ◽  
Dispersed Phase ◽  
Spontaneous Emulsification ◽  
Oil In Water ◽  
Mixing Rates ◽  
Formulation Parameters ◽  
Nano Emulsion

Nano-emulsions consist of stable suspensions of nano-scaled droplets that have huge loading capacities and are formulated with safe compounds. For these reasons, a large number of studies have described the potential uses of nano-emulsions, focusing on various aspects such as formulation processes, loading capabilities, and surface modifications. These studies typically concern direct nano-emulsions (i.e., oil-in-water), whereas studies on reverse nano-emulsions (i.e., water-in-oil) remain anecdotal. However, reverse nano-emulsion technology is very promising (e.g., as an alternative to liposome technology) for the development of drug delivery systems that encapsulate hydrophilic compounds within double droplets. The spontaneous emulsification process has the added advantages of optimization of the energetic yield, potential for industrial scale-up, improved loading capabilities, and preservation of fragile compounds targeted for encapsulation. In this study, we propose a detailed investigation of the processes and formulation parameters involved in the spontaneous nano-emulsification that produces water-in-oil nano-emulsions. The following details were addressed: (i) the order of mixing of the different compounds (method A and method B), (ii) mixing rates, (iii) amount of surfactants, (iv) type and mixture of surfactants, (v) amount of dispersed phase, and (vi) influence of the nature of the oil. The results emphasized the effects of the formulation parameters (e.g., the volume fraction of the dispersed phase, nature or concentration of surfactant, or nature of the oil) on the nature and properties of the nano-emulsions formed.

scholarly journals Rapid demulsification of pickering emulsions triggered by controllable magnetic field

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hui Yang ◽  
Shujuan Wang ◽  
Wei Zhang ◽  
Jiazhong Wu ◽  
Siyu Yang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Oil Recovery ◽  
Solid Particles ◽  
Pickering Emulsions ◽  
Irreversible Adsorption ◽  
Practical Applications ◽  
Oil In Water ◽  
Cyclic Utilization ◽  
The Stability ◽  
Promising Avenue

Abstract Pickering emulsions with on–off properties provide significant advantages over simple solid-stabilized emulsions for the development of novel materials, such as oil-displacing agents for enhanced oil recovery and templates for the fabrication of porous materials. However, the irreversible adsorption of particles as emulsion stabilizers endows the Pickering emulsions with kinetically stable property, resulting in a huge challenge to break the stability. Here we fabricated microscale Pickering emulsions, by the use of paramagnetic particles, which possess excellent stability for several months and more interestingly perform complete demulsification under controllable magnetic fields in several minutes. The alternating asymmetrical magnetic field endows oil-in-water droplets ‘‘big’’ N and S poles on the outer particle layers, and attracts the solid particles to the bottom of the vial after the coalescence and the deformation of the droplets, bringing the prevention of re-emulsion and the cyclic utilization. This facile strategy to produce stable Pickering emulsions with a magnetic-response opens a promising avenue for various practical applications including oil recovery, wastewater treatment, and sludge removal.

The Effect of Silicide Volume Fraction on the Creep Behavior of Nb-Silicide Based In-Situ Composites

2000 ◽  
Vol 646 ◽  
Author(s):  
B.P. Bewlay ◽  
C.L. Briant ◽  
A.W. Davis ◽  
M.R. Jackson
Keyword(s):  
High Temperature ◽  
Creep Rate ◽  
Creep Behavior ◽  
Volume Fraction ◽  
Phase Volume ◽  
In Situ Composites ◽  
Volume Fractions ◽  
Stress Levels

ABSTRACTThis paper will describe the creep behavior of high-temperature Nb-silicide in-situ composites based on quaternary Nb-Hf-Ti-Si alloys. The effect of volume fraction of silicide on creep behavior, and the effects of Hf and Ti additions, will be described. The composites were tested in compression at temperatures up to 1200°C and stress levels in the range 70 to 280 MPa. At high (Nb) phase volume fractions the creep behavior is controlled by deformation of the (Nb) and, as the volume fraction of silicide is increased, the creep rate is reduced. However, at large silicide volume fractions (>0.7) damage in the silicide begins to degrade the creep performance. The creep rate has a minimum at a volume fraction of ∼0.6 silicide. The creep performance of the monolithic and silicide phases will also be discussed.

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