Titre : |
Simple and effective particle-size characterization of opaque emulsions |
Type de document : |
texte imprimé |
Auteurs : |
Lucile Bonnin, Auteur ; Burkhard Müller, Auteur ; Thomas Gassenmeier, Auteur ; Reinhard H. H. Neubert, Auteur |
Année de publication : |
2018 |
Article en page(s) : |
p. 38-44 |
Note générale : |
Bibliogr. |
Langues : |
Anglais (eng) |
Catégories : |
Caractérisation Emulsions -- Emploi en cosmétologie Emulsions -- Stabilité Evaluation Granulométrie Taille des particules
|
Index. décimale : |
668.5 Parfums et cosmétiques |
Résumé : |
Because emulsions are metastable, predicting their stability and phase bahavior is a crucial topic of research. Indeed, emulsions are widely used in the chemical industry and formulators must be able to asses their stability e.g. life-cycle or shelves-life. Although several devices, avaible on the market, are claiming to be able to asses emulsions' stability, they often use laser or ultrasound diffraction techniques which offer limited capabilities for studying opaque emulsions. This study is decribing how the usage of a simple light microscope, already present as a standard equipment in lots of laboratories, can lead to the precise assessment of the particle-size distribution of various cosmetic o/w emulsions. The light microscope was equipped with an objective (40x) having a negative phase-contrast ring. The particle-size characterization by means of phase-contrast microscopy enabled to draw conclusion about the stability over time of two o/w emulsions and to observe the influence of additives on their phase behavior. This novel image analysis method delivered relevant information about the particle-size distribution i.e. stability, of the emulsions at an earlier stage than classical stability tests mathods. |
Note de contenu : |
- Cosmetic O/W opaque emulsion : composition and formulation
- Phase-contrast microscopy
- Fig. 1 : Appearance of the o/w opaque cosmetic emulsion
- Fig. 2 : Microstructure of the o/w emulsion forming a gel network (re-drawn from Klein [9])
- Fig. 3 : 40x objective equipped with a negative phase-contrast (Ph 2) mode
- Fig. 4 : Representation of the phase-contrast microscopy base principle
- Fig. 5 : Image analysis process of the o/w emulsion under phase-contrast microscopy
- Fig. 6 : O/W emulsion's photomicrograph after automatic recognition of the particles clustered according to their radius (R) size
- Fig. 7 : O/W emulsions containing either no (a) or 1% w/w additive (b) under phase-contrast light microscopy at t0
- Fig. 8 : Particle-size distribution of the o/w emulsion containing no additive at t0 and after 3 months storage at RT with N(t0)=13873 and N(3 months)= 12661
- Fig. 9 : Particle-size distribution of the o/w emulsion containing 1% w/w of additive at t0 and after 3 months storage at RT with N(t0)= 10689 and N(3 months)= 10229
- Table 1 : Composition of the opaque cosmetic o/w emulsion
- Table 2 : Statistical results of the particle count for both o/w emulsions at t0 and after 3 months storage at RT |
En ligne : |
https://drive.google.com/file/d/1tV5s3MbmMDc_ID0VGKhlM-NRRxS4LjVX/view?usp=drive [...] |
Format de la ressource électronique : |
Pdf |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=31328 |
in SOFW JOURNAL > Vol. 144, N° 10 (10/2018) . - p. 38-44