title: Effects of aging on structure and stability of TiO2 nanoparticle-containing oil-in-water emulsions.
abstract: Formulations incorporating different cosmetic grade TiO2 nanoparticles were developed according to a self-produced protocol on the basis of typical sunscreen cream oil-in-water emulsions. Role of nanoparticles and, more specifically, the impact of two different lipophilic surface treatments on microstructure and stability of the formulations were assessed. Aging of formulations was performed under classical conditions at room temperature or under accelerated conditions at 50 °C, with or without TiO2, and was characterized by several tools such as rheology, microscopy, and particle size measurements. Changes in emulsion stability and aggregation state of nanoparticles were followed over time. Destabilization phenomena were identified: under accelerated aging, the formulation without nanoparticles underwent a coalescence occurrence whereas the formulation incorporating nanoparticles was subjected to aggregation of the colloidal particles. Besides, TiO2 nanoparticles strongly affected the particle-droplets interactions and thus modified the emulsion microstructure with a coating-dependent effect: destabilization mechanisms occur more rapidly with alumina (and) triethoxycaprylylsilane (coating 1) TiO2 nanoparticles as compared to alumina (and) isopropyl titanium triisostearate (and) triethoxycaprylylsilane crosspolymer (coating 2) nanoparticles.
authors.affiliation: URCOM, EA 3221, FR CNRS 3038, University of Le Havre, 25 rue Philippe Lebon B.P. 540, 76058 Le Havre Cedex, France; LEMA, EA 3222, University of Le Havre, 25 rue Philippe Lebon B.P. 540, 76058 Le Havre Cedex, France.
authors.forename: Manon
authors.initials: M
authors.lastname: Rossano
authors.affiliation: URCOM, EA 3221, FR CNRS 3038, University of Le Havre, 25 rue Philippe Lebon B.P. 540, 76058 Le Havre Cedex, France. Electronic address: nicolas.hucher@univ-lehavre.fr.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Hucher
authors.affiliation: URCOM, EA 3221, FR CNRS 3038, University of Le Havre, 25 rue Philippe Lebon B.P. 540, 76058 Le Havre Cedex, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Picard
authors.affiliation: URCOM, EA 3221, FR CNRS 3038, University of Le Havre, 25 rue Philippe Lebon B.P. 540, 76058 Le Havre Cedex, France.
authors.forename: Daniel
authors.initials: D
authors.lastname: Colletta
authors.affiliation: LEMA, EA 3222, University of Le Havre, 25 rue Philippe Lebon B.P. 540, 76058 Le Havre Cedex, France.
authors.forename: Frank
authors.initials: F
authors.lastname: Le Foll
authors.affiliation: URCOM, EA 3221, FR CNRS 3038, University of Le Havre, 25 rue Philippe Lebon B.P. 540, 76058 Le Havre Cedex, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Grisel
mesh_terms: D002626:Chemistry, Pharmaceutical / Q000379:methods; D003102:Colloids; D004356:Drug Storage; D004655:Emulsions; D008853:Microscopy; D053758:Nanoparticles; D009821:Oils / Q000737:chemistry; D010316:Particle Size; D012212:Rheology; D013473:Sunscreening Agents / Q000008:administration & dosage / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D014025:Titanium / Q000008:administration & dosage / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D003102:Colloids; D004655:Emulsions; D009821:Oils; D013473:Sunscreening Agents; D014867:Water; C009495:titanium dioxide; D014025:Titanium
keywords: Alumina (PubChem CID 14769); Coating; Destabilization; Isopropyl titanium triisostearate (PubChem CID 162941); Particle size measurement; Rheology; Sunscreen; Titanium dioxide (PubChem CID 26042); Titanium dioxide nanoparticle; Triethoxycaprylylsilane (PubChem CID 76262)