Formation of Concentrated Nanoemulsions by Extreme Shear

Meleson, K.; Graves, Sara M.; Mason, Thomas G.

doi:10.1081/smts-200056102

Cited by 175 publications

(150 citation statements)

References 29 publications

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“…Moreover, as N increases, the average radius decreases initially, yet it begins to saturate toward a constant value, a s , at the largest N we explore. To characterize the decrease, we fit each a(N ) at a particular pressure to the following empirical equation [10]:…”

Section: Resultsmentioning

confidence: 99%

“…Microfluidic and ultrasonic techniques both produce the kind of extreme shear that is required to break emulsions down to diameters below 100 nm [7][8][9]. Sub-micron emulsions are sometimes called "mini-emulsions", and we define "nanoemulsions" to be emulsions having diameters around 100 nm or less [10]. Because the submicroscopic droplet sizes make it difficult to observe the droplets and because very strong shear is required to create them, nanoemulsions have been studied far less than conventional emulsions.…”

Section: Introductionmentioning

confidence: 99%

“…We have developed a systematic procedure using a high-pressure microfluidic device to create bulk quantities of oil in water nanoemulsions with diameters as small as 30 nm [10]. Although the raw nanoemulsions have a peaked monomodal size distribution, as determined by dynamic light scattering, we use ultracentrifugation to fractionate the droplets and make them more monodisperse.…”

Section: Introductionmentioning

confidence: 99%

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Extreme emulsification: formation and structure of nanoemulsions

Mason¹,

Graves²,

Wilking³

et al. 2006

Condens. Matter Phys.

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Nanoemulsions are metastable dispersions of nanodroplets of one liquid that have been ruptured by shear in another immiscible liquid. The ruptured droplets are stabilized against subsequent coalescence by a surfactant. Because the nanodroplets do not form spontaneously, as they can in lyotropic "microemulsion" phases, the structure of nanoemulsions is primarily dependent on the history of the applied shear stresses relative to the interfacial restoring stresses. By applying extremely high shear rates and controlling the composition of the emulsion, we have been able to rupture microscale droplets down to diameters as small as 30 nm in a microfluidic process that yields bulk quantities suitable for commercial production. Following ultracentrifugal fractionation to make the droplets uniform, we study the structure of these emulsions using small angle neutron scattering (SANS) at dilute and concentrated volume fractions. We contrast the structure of a concentrated nanoemulsion with the structure factor of hard spheres at a similar volume fraction.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Extreme emulsification: formation and structure of nanoemulsions

Mason¹,

Graves²,

Wilking³

et al. 2006

Condens. Matter Phys.

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“…We first create a polydisperse microscale oil-in-water premix emulsion by emulsifying trimethyl-terminated polydimethylsiloxane (PDMS) silicone oil (viscosity 10 cSt, mass density 0.935 g/cm 3 , Gelest) at ϕ = 0.3 into a 20 mM aqueous SDS solution (MP Biomedicals, Ultrapure) (Meleson et al 2004). We process this premix emulsion at a liquid pressure of 10,000 psi through a 75-μm Y-type diamond interaction chamber using a Microfluidics M-110P homogenizer, recirculating for three passes using a cooling coil immersed in an ice-water bath.…”

Section: Methodsmentioning

confidence: 99%

Entropic, electrostatic, and interfacial regimes in concentrated disordered ionic emulsions

2016

Self Cite

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We develop a free energy model that describes two key thermodynamic properties, the osmotic pressure Π and the linear elastic shear modulus G′ p (i.e. plateau storage modulus), of concentrated monodisperse emulsions which have isotropic, disordered, droplet structures, and are stabilized using ionic surfactants. This model effectively incorporates the concept of random close packing or jamming of repulsive spheres into a free energy F that depends on droplet volume fraction ϕ and shear strain γ both below and above the a critical jamming point ϕ c ≈ 0.646. This free energy has three terms: entropic, electrostatic, and interfacial (EEI). By minimizing F with respect to an average droplet deformation parameter that links all three terms, we show that the entropic term is dominant for ϕ well below ϕ c , the electrostatic term is dominant for ϕ near but below ϕ c , and the interfacial term dominates for larger ϕ. This EEI model describes measurements of G′ p (ϕ) for charge-stabilized uniform emulsions having a wide range of droplet sizes, ranging from nanoscale to microscale, and it also is consistent with measurements of Π(ϕ). Moreover, it describes G′ p (ϕ) for similar nanoemulsions after adding non-amphiphilic salt, when changes in the interfacial tension and the Debye screening length are properly taken into account. By unifying existing approaches, the EEI model predicts constitutive properties of concentrated ionic emulsions that have disordered, out-ofequilibrium structures through near-equilibrium free energy minimization, consistent with random driving Brownian excitations.

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“…Whatever the CMC is achieved in lower concentration of hydrophilic polymer (<135 mg/ml), the formed polymeric micelle would be more resistant to dilution effect. [9] Lower CMC conferred by two different strategies: (1) Increasing the chain length of the core-forming polymer. [10] (2) Decreasing the chain length of hydrophilic shell-forming polymer.…”

Section: Micelle Formation Mechanismmentioning

confidence: 99%

Untitled

Esfahani¹

2017

AJP

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Almost half of the orally administered drugs are poorly soluble in water; therefore they have low absorption in the gastrointestinal (GI) tract. In addition, drugs which are administered orally must remain stable during passing the GI tract, despite different physiologic challenges such as pH changes, and dilution effect. Hence, new methods are needed to increase the solubility of these drugs while making them more stable in the physiologic environment. Polymeric micelles are one of the new nanocarriers which are able to increase the solubility of these drugs while protecting them from pH changes, dilution effect, and biological barriers such as filtration in the spleen or scavenging by the phagocytic system. This article provides some important and basic information including polymeric micelles characteristics, structure, and preparation.

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Formation of Concentrated Nanoemulsions by Extreme Shear

Cited by 175 publications

References 29 publications

Extreme emulsification: formation and structure of nanoemulsions

Extreme emulsification: formation and structure of nanoemulsions

Entropic, electrostatic, and interfacial regimes in concentrated disordered ionic emulsions

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