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. 2019 Feb 14;9(2):259.
doi: 10.3390/nano9020259.

Oil-in-Water Emulsions Stabilized by Cellulose Nanofibrils-The Effects of Ionic Strength and pH

Ragnhild Aaen  1 , Fredrik Wernersson Brodin  2 , Sébastien Simon  3 , Ellinor Bævre Heggset  4 , Kristin Syverud  5   6
Affiliations

Oil-in-Water Emulsions Stabilized by Cellulose Nanofibrils-The Effects of Ionic Strength and pH

Ragnhild Aaen et al. Nanomaterials (Basel). .

Abstract

Pickering o/w emulsions prepared with 40 wt % rapeseed oil were stabilized with the use of low charged enzymatically treated cellulose nanofibrils (CNFs) and highly charged 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized CNFs. The emulsion-forming abilities and storage stability of the two qualities were tested in the presence of NaCl and acetic acid, at concentrations relevant to food applications. Food emulsions may be an important future application area for CNFs due to their availability and excellent viscosifying abilities. The emulsion characterization was carried out by visual inspection, light microscopy, viscosity measurements, dynamic light scattering and mild centrifugation, which showed that stable emulsions could be obtained for both CNF qualities in the absence of salt and acid. In addition, the enzymatically stabilized CNFs were able to stabilize emulsions in the presence of acid and NaCl, with little change in the appearance or droplet size distribution over one month of storage at room temperature. The work showed that enzymatically treated CNFs could be suitable for use in food systems where NaCl and acid are present, while the more highly charged TEMPO-CNFs might be more suited for other applications, where they can contribute to a high emulsion viscosity even at low concentrations.

Keywords: TEMPO-oxidation; cellulose nanofibrils (CNFs); emulsion stability; enzymatical treatment; nanocelluloses; o/w emulsions.

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Conflict of interest statement

The authors declare no conflict of interest. The founding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results.

Figures

Figure 1
Figure 1
Scanning electron microscopy (SEM) images of the top surface of air-dried CNF films recorded at 100× and 10,000× magnification of enzymatically treated CNFs (upper) and TEMPO-oxidized CNFs (lower).
Figure 2
Figure 2
Pictures of the CNF-stabilized emulsions with 0.5 wt % CNFs, containing acetic acid and/or salt. The pictures are taken after (a) one day and (b) one month of storage at 23 °C.
Figure 3
Figure 3
Light microscopy images taken after one month of storage, as well as the droplet size distributions over time for emulsions stabilized with 0.5 wt % CNF-E, for (a) a reference emulsion, (b) an emulsion with 0.2 wt % acetic acid, (c) an emulsion with 1.0 wt % NaCl and (d) an emulsion with 0.2 wt % acetic acid and 1.0 wt % NaCl.
Figure 4
Figure 4
Light microscopy images taken after one month of storage, as well as the droplet size distributions over time for emulsions stabilized with 0.5 wt % CNF-T, for (a) a reference emulsion, (b) an emulsion with 0.2 wt % acetic acid, (c) an emulsion with 1.0 wt % NaCl and (d) an emulsion with 0.2 wt % acetic acid and 1.0 wt % NaCl.
Figure 5
Figure 5
Pictures of emulsions stabilized by CNF-E (upper) or CNF-T (lower) with the addition of acetic acid and NaCl, taken after centrifugation, with two replicates for each sample.
See this image and copyright information in PMC

References

    1. Arslan-Alaton I., Erdinc E. Effect of photochemical treatment on the biocompatibility of a commercial nonionic surfactant used in the textile industry. Water Res. 2006;40:3409–3418. doi: 10.1016/j.watres.2006.07.014. - DOI - PubMed
    1. Gomez V., Ferreres L., Pocurull E., Borrull F. Determination of non-ionic and anionic surfactants in environmental water matrices. Talanta. 2011;84:859–866. doi: 10.1016/j.talanta.2011.02.009. - DOI - PubMed
    1. Jardak K., Drogui P., Daghrir R. Surfactants in aquatic and terrestrial environment: Occurrence, behavior, and treatment processes. Environ. Sci. Pollut. Res. 2016;23:3195–3216. doi: 10.1007/s11356-015-5803-x. - DOI - PubMed
    1. Pickering S.U. CXCVI.-Emulsions. J. Chem. Soc. Trans. 1907;91:2001–2021. doi: 10.1039/CT9079102001. - DOI
    1. Ramsden W. Separation of solids in the surface-layers of solutions and ’suspensions’ (observations on surface-membranes, bubbles, emulsions, and mechanical coagulation).—Preliminary account. Proc. R. Soc. Lond. 1903;72:156–164.

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