The partitioning of emulsifiers in o/w emulsions: A comparative study of SANS, ultrafiltration and dialysis

Oehlke, Kathleen; Garamus, Vasil M.; Heins, Anja; Stöckmann, Heiko; Schwarz, Karin

doi:10.1016/j.jcis.2008.02.042

Cited by 29 publications

(28 citation statements)

References 54 publications

(86 reference statements)

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“…The difficulty arises from the fact that it is physically impossible to isolate the interfacial region from the oil or water ones, and this means that any attempt to measure the distribution of emulsion components needs to be carried out in the intact emulsion. Several researchers approached the problem of determining the antioxidant distribution in emulsions using a combination of ultracentrifugation techniques followed by determination of analyte concentrations by employing different analytical tools in combination with mathematical models to determine the distribution of molecules of interest in a variety of emulsified systems . The methods, however, do not provide the percentage of antioxidant in the interfacial region and the obtained results can be biased because the emulsion is broken previous to any measurement …”

Section: Introductionmentioning

confidence: 99%

Effects of acidity and emulsifier concentration on the distribution of vitamin C in a model food emulsion

Pastoriza-Gallego

Losada‐Barreiro

2012

J of Physical Organic Chem

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We have analyzed the effects of acidity and emulsifier concentration on the distribution of ascorbic acid or vitamin C (VC) in a model emulsion prepared by mixing octane, acidic (HCl) water and the non‐ionic surfactant hexaethyleneglycol monododecyl ether (C12E6). VC is oil insoluble, and only the partition constant between the interfacial and aqueous regions (PWI) is needed to describe its distribution within the emulsion. The PWI values are calculated from the kinetic analyses of the variation of the observed rate constant (kobs) determined electrochemically for the reaction between the hydrophobic 4‐hexadecylbenzenediazonium (16‐ArN2+) ions and VC with the emulsifier concentration. The determined PWI values (PWI = 4–25) are low in comparison with those obtained for more hydrophobic antioxidants like vitamin E, and pH dependent, decreasing upon decreasing the acidity of the medium. These low values are reflected in the distribution of VC so that a large fraction (70%) is located in the aqueous region at low emulsifier concentrations. At a given pH, the %VC in the aqueous region decreases upon increasing the emulsifier concentration; meanwhile, at a given emulsifier concentration %VC increases upon lowering the acidity. The intrinsic rate constants in the interfacial region kI for the reaction between 16‐ArN2+ and VC have also been determined at different acidities. Their variation with the pH follows an upward bend curve, suggesting an inverse dependence of kI with the acidity of the medium, in keeping with the proposed mechanism for the reaction. The results may be of some interest to the food and pharmaceutical industries because of the extensive use of VC as antioxidant or preservative and because of the health benefits of VC. Copyright © 2012 John Wiley & Sons, Ltd.

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Section: Introductionmentioning

confidence: 99%

Effects of acidity and emulsifier concentration on the distribution of vitamin C in a model food emulsion

Pastoriza-Gallego

Losada‐Barreiro

2012

J of Physical Organic Chem

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“…However, for monomer/water emulsions, due to the solubilization of monomer in micelles, micelles may be formed before the interface is completely covered [48][49][50]. Hence, the equilibrium between adsorbed surfactant molecules at the interface and free surfactant molecules in the bulk has to be regarded.…”

Section: Determination Of the Ideal Surfactant Concentrationmentioning

confidence: 99%

Continuous Preparation of Polymer/Inorganic Composite Nanoparticles via Miniemulsion Polymerization

Merkel

Hecht

Schoth

et al. 2015

Colloid Process Engineering

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Composite nanostructured particles can be produced by polymerization of monomer miniemulsion droplets loaded with inorganic nanoparticles. The article gives an overview on the development of a scalable continuous process for the production of such hybrid nanoparticles via miniemulsion polymerization. Different possibilities for the necessary surface modification of the inorganic material are discussed in detail. Furthermore, the influence of the surfactant concentration on the droplet size after emulsification as well as on the nucleation mechanisms during polymerization is highlighted. Possible process routes for the emulsification of the nanoparticle-loaded monomer phase are compared taking into account different process and material parameters, such as energy consumption, abrasion, dispersed phase viscosity, inorganic particle load and size, and morphology of the resulting hybrid particles. The possibility of an industrial implementation via an integrated high pressure homogenization process and a subsequent continuous polymerization are presented.

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“…Before estimating the oligonucleotides association efficiency, the membrane recovery was evaluated to verify whether any adsorption or interaction mechanisms between oligonucleotides and the ultrafiltration units had occurred 20 ( Figure 2). Irrespective of oligonucleotides concentration (0.5 to 20 nmol/mL) and type (phosphodiester or phosphorothioate), the recovery proved to be higher than 92%.…”

Section: Uv Spectra Of Phosphodiester and Phosphorothioate Oligonucmentioning

confidence: 99%

Validation of a spectrophotometric method to estimate the adsorption on nanoemulsions of an antimalarial oligonucleotide

2011

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Recebido em 3/12/10; aceito em 22/3/11; publicado na web em 10/6/11This study describes the validation of a spectrophotometric method to estimate oligonucleotides association with cationic nanoemulsions. Phosphodiester and phosphorothioate oligonucleotides targeting Plasmodium falciparum topoisomerase II were analyzed at 262 nm. Linear response (r > 0.998) was observed from 0.4 to 1.0 nmol/mL, the relative standard deviation values for the intra-and inter-days precision were lower than 2.6% and the recovery ranged from 98.8 to 103.6% for both oligonucleotides. The association efficiency was estimated based on an ultrafiltration/centrifugation method. Oligonucleotides recovery through 30 kDa-membranes was higher than 92%. The extent of oligonucleotides association (42 to 98%) varied with the composition of nanoemulsions.

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The partitioning of emulsifiers in o/w emulsions: A comparative study of SANS, ultrafiltration and dialysis

Cited by 29 publications

References 54 publications

Effects of acidity and emulsifier concentration on the distribution of vitamin C in a model food emulsion

Effects of acidity and emulsifier concentration on the distribution of vitamin C in a model food emulsion

Continuous Preparation of Polymer/Inorganic Composite Nanoparticles via Miniemulsion Polymerization

Validation of a spectrophotometric method to estimate the adsorption on nanoemulsions of an antimalarial oligonucleotide

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