Accueil
Détail de l'auteur
Auteur L. Xu |
Documents disponibles écrits par cet auteur
Ajouter le résultat dans votre panier Affiner la recherche
Interfacial composition and structural parameters of aqueous NaCl(HCl/NaOH)/CnmimBr/1-pentanol/n-octane microemulsions / L. Xu in TENSIDE, SURFACTANTS, DETERGENTS, Vol. 48, N° 6 (11-12/2011)
[article]
Titre : Interfacial composition and structural parameters of aqueous NaCl(HCl/NaOH)/CnmimBr/1-pentanol/n-octane microemulsions Type de document : texte imprimé Auteurs : L. Xu, Auteur ; J.-L. Chai, Auteur ; W. Liu, Auteur ; S. S. Shang, Auteur ; J.-J. Lu, Auteur Année de publication : 2011 Article en page(s) : p. 459-465 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Chimie des surfaces
Dilution
Liquides ioniques
Microémulsions
SurfactantsIndex. décimale : 668.5 Parfums et cosmétiques Résumé : The interfacial composition, thermodynamic properties and structure parameters of the W/O microemulsion systems containing alkyl-3-methyl imidazolium bromide (CnmimBr, n = 12, 14, 16)/1-pentanol/n-octane/aqueous NaCl (HCl or NaOH) have been studied by a dilution method. The molar solubility of 1-pentanol in oil phase (X0a) and the molar fraction of 1-pentanol at the interfacial layer (Xia) were obtained from the dilution equation of the W/O microemulsions. Furthermore, the distribution constant K of 1-pentanol between the interfacial layer and the bulk oil phase was determined, along with the standard Gibbs’ free energy change of transferring alcohol from the continuous oil phase to the interfacial layer, –ΔG00 -> i. Some structure parameters related to the microemulsion droplets were also calculated. The effects of NaCl, HCl and NaOH on the properties and structures of the W/O microemulsions were also explored. It was found that as the content of the aqueous NaCl (HCl and NaOH) increases, X0a and Xia would decrease, the formation of the microemulsion would be more thermodynamically spontaneous, and the radius of the water pool significantly increases. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=12614
in TENSIDE, SURFACTANTS, DETERGENTS > Vol. 48, N° 6 (11-12/2011) . - p. 459-465[article]Réservation
Réserver ce documentMicrorheological study of ternary surfactant-biosurfactant mixtures / L. Xu in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Vol. 41, N° 4 (08/2019)
[article]
Titre : Microrheological study of ternary surfactant-biosurfactant mixtures Type de document : texte imprimé Auteurs : L. Xu, Auteur ; Samiul Amin, Auteur Année de publication : 2019 Article en page(s) : p. 364-370 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Biosurfactants
Cocamidopropyl bétaine
Cosmétiques
Formulation (génie chimique) -- Stabilité
Laureth sulfate de sodium
Rhamnolipides
RhéologieIndex. décimale : 668.5 Parfums et cosmétiques Résumé : - Objective : The main objective of this paper is to understand the rheological impact of rhamnolipids biosurfactant (mono/dirhamnolipids mixture, CCB) on a common personal care mixed surfactants system: anionic sodium laureth sulfate (SLES) and zwitterionic cocamidopropyl betaine (CAPB). The ternary biosurfactant/surfactants mixtures were evaluated at three different formulation conditions. The experimental results can provide a formulation guideline when applying rhamnolipids in cosmetics and personal care products.
- Methods : Traditional mechanical rheometer was used to measure bulk viscosity and lower frequency rheological behaviour of ternary surfactant mixtures. Diffusing wave spectroscopy (DWS) was utilized to access rheological responses at high frequency regime. Structural parameters such as contour length, entanglement length and persistence length of wormlike micelles in the anionic/zwitterionic/biosurfactant mixtures can be extracted from the rheological data gathered by DWS.
- Results : Maxwellian type response was present in SLES/CAPB/CCB system which indicated the formation of wormlike micelle. Contour length of wormlike micelle formed by SLES/CAPB reduced from 445.8 to 88.37 nm with only 2 wt% addition of CCB. In the same system, viscosity decreased and shorter relaxation time were observed. Addition of sodium chloride built the viscosity of SLES/CAPB/CCB to an extent by screening charges between surfactant head groups. Highest viscosity of SLES/CAPB/CCB (10 wt%, 2wt% and 4wt% respectfully) was observed when sodium chloride concentration was at 4 wt%. In the same SLES/CAPB/CCB system, pH impacted the system's rheological response significantly. Due to the zwitterionic nature of CAPB, it became more cationic at lower pH while rhamnolipids became more nonionic. SLES still maintained its anionic nature at low pH and this promoted the interaction between CAPB and SLES. At lower pH, overall loss and storage modulus exhibited higher values while longer relaxation times were observed. Increase in micelles contour length under lower pH conditions were shown by the DWS data.
- Conclusion : This preliminary rheological and microstructure study of the complex biosurfactant/surfactants ternary systems revealed the effect of formulation conditions on the mixtures rheological responses.Note de contenu : - MATERIALS AND METHODS : Effect of ratio - Effect of adding salt - Effect of pH - Technique
- RESULTS AND DISCUSSION : Effect of ratio - Effect of salt addition - Effect of pHDOI : 10.1111/ics.12549 Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=33115
in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE > Vol. 41, N° 4 (08/2019) . - p. 364-370[article]Réservation
Réserver ce document