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Utilization of carboxymethyl chitosan in cosmetics / A. Jimtaisong in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Vol. 36, N° 1 (02/2014)
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Titre : Utilization of carboxymethyl chitosan in cosmetics Type de document : texte imprimé Auteurs : A. Jimtaisong, Auteur ; N. Saewan, Auteur Année de publication : 2014 Article en page(s) : p. 12-21 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Antimicrobiens
Antioxydants
Carboxyméthyl chitosane
Diffusion (physique)
Eau -- Rétention
Emulsions -- Emploi en cosmétologie
Solubilité
Stabilisants (chimie)
Toxicologie cellulaire
VectorisationIndex. décimale : 668.5 Parfums et cosmétiques Résumé : Le carboxyméthyl chitosane est un des dérivés les plus étudiés du chitosane en raison de sa solubilité dans l'eau dans la gamme de pH la plus large par rapport à la molécule mère ; ainsi son utilisation s'est étendue dans diverses applications. Dans cette revue, les différentes conditions de préparation qui en résultent dans le chitosane N et le O-carboxylé, le degré divers de substitution et leur solubilités dans l'eau sont récapitulés. Cinq caractéristiques importantes de carboxyméthylchitosane d’études récentes, qui sont l'absorption ou la rétention d'humidité, les propriétés antimicrobiennes, les capacités anti-oxydantes, le système de vectorisation et de stabilisation des émulsions, ont été évalués pour l'utilisation cosmétique. En outre, les informations de cytotoxicité ont été incorporées pour assurer sa sécurité dans les applications. Note de contenu : - PREPARATIONS AND PROPERTIES OF CARBOXYMETHYL CHITOSAN : Use of carboxymethyl chitosan in cosmetics - Moisture absorption-retention properties of carboxymethyl chitosan - Anti-microbial activities of carboxymethyl chitosan - Antioxidant activities of carboxymethyl chitosan - Application of carboxymethyl chitosan in delivery system - Carboxymethyl chitosan as an emulsion stabilizer
- THE SAFETY ISSUE OF CARBOXYMETHYL CHITOSANDOI : 10.1111/ics.12102 En ligne : http://onlinelibrary.wiley.com/doi/10.1111/ics.12102 Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=20508
in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE > Vol. 36, N° 1 (02/2014) . - p. 12-21[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 15985 - Périodique Bibliothèque principale Documentaires Disponible Viscosity analysis of a polymer-based drug delivery system using open-source CFD methods and high-pressure capillary rheometry / Herwig Rainer Juster in INTERNATIONAL POLYMER PROCESSING, Vol. XXIX, N° 5 (11/2014)
[article]
Titre : Viscosity analysis of a polymer-based drug delivery system using open-source CFD methods and high-pressure capillary rheometry Type de document : texte imprimé Auteurs : Herwig Rainer Juster, Auteur ; T. Distlbacher, Auteur ; Georg Steinbichler, Auteur Année de publication : 2014 Article en page(s) : p. 570-578 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Diffusion (physique)
Fluides numérique, Mécanique desLa mécanique des fluides numérique (MFN), plus souvent désignée par le terme anglais computational fluid dynamics (CFD), consiste à étudier les mouvements d'un fluide, ou leurs effets, par la résolution numérique des équations régissant le fluide. En fonction des approximations choisies, qui sont en général le résultat d'un compromis en termes de besoins de représentation physique par rapport aux ressources de calcul ou de modélisation disponibles, les équations résolues peuvent être les équations d'Euler, les équations de Navier-Stokes, etc.
La MFN a grandi d'une curiosité mathématique pour devenir un outil essentiel dans pratiquement toutes les branches de la dynamique des fluides, de la propulsion aérospatiale aux prédictions météorologiques en passant par le dessin des coques de bateaux. Dans le domaine de la recherche, cette approche est l'objet d'un effort important, car elle permet l'accès à toutes les informations instantanées (vitesse, pression, concentration) pour chaque point du domaine de calcul, pour un coût global généralement modique par rapport aux expériences correspondantes.
Médicaments
Modèles mathématiques
Polymères
Rhéologie
ViscositéIndex. décimale : 668.9 Polymères Résumé : In this study the viscosity behavior of the polymer-based drug delivery system (Soluplus-Fenofibrate) at high shear rates was investigated using (i) Computational Fluid Dynamics (CFD) methods and (ii) experimental data acquired with a high-pressure capillary rheometer. The barrel and capillary were rebuilt in the virtual domain by means of finite-volume methods and used for fluid dynamic simulations. Our primary focus was on validating the Carreau-Winter and Yasuda material models in the Open Field Operation and Manipulation program (OpenFOAM) and investigating their usefulness in this type of simulation. First, the models were fitted to experimental data from a well-known system – polystyrene type (145D, BASF). The results showed that the Yasuda model fit must be applied to obtain the correct material properties when simulating a non-Newtonian melt flow in a wide range of shear rates. The Carreau-Winter model was found to be valid only in the zero shear-rate viscosity region. On the basis of these findings, the Soluplus-Fenofibrate system was subsequently characterized and simulated. We observed that Fenofibrate (lipid-regulating agent) acts as a plasticizer in this polymer system and decreases system viscosity at lower shear rates compared to pure the Soluplus (polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer) at the same temperatures. Our results show that the viscosity models can be implemented accurately even for processes with high shear rates, which also involve high temperatures. Note de contenu : - EXPERIMENTAL : 1. Material - 2. Measurement method - 3. Analysis of experimental data for viscosity model parameters - 4. Additional material testing
- MODELING : 1. Assumptions on polymer flow - 2. Governing equations - 3. Operating conditions - 4. Solver
- VALIDATION OF MATERIAL MODELS : 1. Implementation of Carreau model in openfoam - 2. Implementation of the Carreau model in the whinrheo II rheological evaluation program - 3. Comparison of model parameters: Carreau-Winter vs Yasuda - 4. Results of the model comparison
- SIMULATION OF THE SOLUPLUS-FENOFIBRATE SYSTEMDOI : 10.3139/217.2892 En ligne : https://drive.google.com/file/d/1IqqZ2e6FnJ8NfOZjhlRYpgEKPUZHo92S/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=22222
in INTERNATIONAL POLYMER PROCESSING > Vol. XXIX, N° 5 (11/2014) . - p. 570-578[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 16633 - Périodique Bibliothèque principale Documentaires Disponible Water concentration distribution in coatings during accelerated weathering protocols / Brian R. Hinderliter in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 12, N° 3 (05/2015)
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Titre : Water concentration distribution in coatings during accelerated weathering protocols Type de document : texte imprimé Auteurs : Brian R. Hinderliter, Auteur ; Erik D. Sapper, Auteur Année de publication : 2015 Article en page(s) : p. 477-487 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Diffusion (physique)
Durée de vie (Ingénierie)
Essais accélérés (technologie)
Prévision, Théorie de la
Revêtements -- Effets de l'humidité:Peinture -- Effet de l'humiditéIndex. décimale : 667.9 Revêtements et enduits Résumé : The long outdoor service life of painted metal and wood objects, often measured in decades, requires the use of accelerated weathering protocols to predict the long-term efficacy and performance of new barrier protective coating candidates. The mechanism of damage imposed on a coating system in accelerated weathering tests must have parity with the damage mechanisms occurring within the system as it undergoes natural, in-service weathering. Similarly, the physical conditions involved in the accelerated exposure regime, including water distribution as it is defined both temporally and spatially, must show equivalency to the natural exposure regime. An added complication in accurately accelerating coating damage is that the wet and dry cycles of accelerated weathering and corrosion test protocols are often performed at different and elevated temperatures from in-service exposure, which results in altered bulk transport and diffusion rates of water during each phase of the weathering or corrosion protocol, when compared to those rates experienced in field or in-service conditions. In this study, Fick’s law of diffusion is applied to coating surfaces exposed to surface water concentrations at cyclical intervals for a set of two-stage accelerated weathering protocols. The governing equations are solved using Laplace transforms followed by time rescaling to account for the variation in temperature, which impacts the diffusion coefficient between the wet and dry portions of several accelerated weathering protocols. This serves to predict the asymptotic average water concentration within the coating as well as at the coating–metal interface, based on the diffusion and temperature parameters of the coating and the parameters of the accelerated weathering protocol, including the duration of each imposed wet or dry stage. The analytic solution to Fick’s second law also allows the water concentration at the substrate–coating interface to be predicted based on Arrhenius parameters of the diffusion process. This resultant average time of wetness and water concentration variance at the coating–substrate interface can be used to more directly compare corrosion and adhesion loss between various accelerated weathering protocols and natural weathering conditions. The numerical average and range of water concentration as a function of coating depth can then be used to interpret coating damage distribution with depth, and enable more insightful comparison of the results of various accelerated weathering protocols. The simulations indicate that good barrier systems may actually exhibit increased barrier properties in accelerated protocols as compared to systems with mediocre or poor barrier performance as determined by global diffusion coefficients. The good barrier coating imparts substantially less exposure challenge to the interface than the mediocre or poor barrier coatings in accelerated weathering protocols. Therefore, in industry-standard tests, the observed performance gain of good barrier coating systems over poor systems may be unduly exaggerated. However, the overall exposure challenge to the interface of a good barrier coating is likely to be larger in service or field conditions due to the much extended time of wet exposure. Thus, laboratory-accelerated weathering cycles that do not consider the impact of temporal and spatial diffusion could potentially misrepresent the quality of a coating, in most cases overestimating the performance of coatings with good baseline barrier protection for adhesion or corrosion protection. In other words, the accelerated weathering protocols do not equally challenge the interface of different coatings operating in the same in-service conditions. Note de contenu : - Analytic solution method to cyclic boundary conditions
- Nondimensionalization of cyclic Fickian diffusion
- Spatial solution to diffusion equation in Laplace space
- Asymptotic average concentration at metal interface and throughout
- Series solution to cyclic water boundaryDOI : 10.1007/s11998-015-9661-8 En ligne : https://link.springer.com/content/pdf/10.1007%2Fs11998-015-9661-8.pdf Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=24172
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Code-barres Cote Support Localisation Section Disponibilité 17244 - Périodique Bibliothèque principale Documentaires Disponible Water sorption and diffusional properties of a cured epoxy resin measured using alternating ionic liquids/aqueous electrolytes in electrochemical impedance spectroscopy / Brian R. Hinderliter in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 5, N° 4 (12/2008)
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Titre : Water sorption and diffusional properties of a cured epoxy resin measured using alternating ionic liquids/aqueous electrolytes in electrochemical impedance spectroscopy Type de document : texte imprimé Auteurs : Brian R. Hinderliter, Auteur ; Stuart G. Croll, Auteur ; Dennis E. Tallman, Auteur ; Gordon P. Bierwagen, Auteur ; Kerry N. Allahar, Auteur Année de publication : 2008 Article en page(s) : p. 431-438 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Diffusion (physique)
Electrochimie
Electrolytes
Epoxydes
Liquides ioniques
Spectroscopie d'impédance électrochimiqueIndex. décimale : 667.9 Revêtements et enduits Résumé : The protective quality of a coating is often measured by how long it delays the arrival of water to the substrate. The transport of water in, redistribution within, and eventually through a coating to the substrate has long been investigated through electrochemical impedance spectroscopy (EIS). EIS measurements employing alternating nonaqueous (room temperature ionic liquids, RTIL) and aqueous electrolytes elucidated the behavior of water within the coating. Diffusion coefficients could be measured and the redistribution of water into percolating paths identified. The use of RTIL alternating with aqueous electrolytes allows determination of intrinsic properties (water volume fraction at saturation and relative dielectric) and kinetic properties predicted by the Brasher Kingsbury formulation. This article focuses on the sensitivity of these intrinsic and kinetic properties to test duration in an unique experimental method. DOI : 10.1007/s11998-008-9107-7 En ligne : https://link.springer.com/content/pdf/10.1007%2Fs11998-008-9107-7.pdf Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3468
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Code-barres Cote Support Localisation Section Disponibilité 010911 - Périodique Bibliothèque principale Documentaires Disponible