Accueil
Résultat de la recherche
3 résultat(s) recherche sur le tag ''chemical'
Ajouter le résultat dans votre panier Affiner la recherche Générer le flux rss de la recherche
Partager le résultat de cette recherche
Change in surface chemistry of the cuticle of human hair by chemical and photochemical oxidation / Sigrid B. Ruetsch in IFSCC MAGAZINE, Vol. 7, N° 4 (10-11-12/2004)
[article]
Titre : Change in surface chemistry of the cuticle of human hair by chemical and photochemical oxidation Type de document : texte imprimé Auteurs : Sigrid B. Ruetsch, Auteur ; Yash K. Kamath, Auteur Année de publication : 2004 Article en page(s) : p. 299-307 Note générale : Bibliogr. Langues : Anglais (eng) Tags : 'Chemical and photochemical oxidation' 'surface lipids (F-layer)' microfluorometry 'single fiber surface wettability scanning' 'fiber-to-fiber friction force measurements' 'X-ray photoelectron spectroscopy' Index. décimale : 668.5 Parfums et cosmétiques Résumé : This is a multifaceted study on the characterization and quantification of damage to the hair fiber surface caused by photochemical and cosmetic chemical oxidative processes. Unique techniques were used, including a microfluorometric method that had been adapted to characterize and quantify the delipidation and acidification of the human hair surface during light exposure and cosmetic chemical grooming processes such as bleaching. During photochemical and chemical oxidation, breakdown of the lipid domains (also called the F-layer) of the outer b-layer occurs on the exposed scale faces and cysteic acid groups are generated on the cuticle cell surface. The newly formed acid functionalities can be tagged with the cationic fluorochrome Rhodamine B, allowing not only quantification of the level of progressive acidification but also localization of the newly formed acid functionalities. On the other hand, the negative charges generated on the hair surface by oxidation can also bind low molecular weight quaternary cationic conditioning compounds such as cetyltrimethylammonium bromide. This process can be considered a relipidation by adsorption. We have shown that the entire process of delipidation/acid formation and subsequent relipidation by adsorption on the scale faces can be quantified by X-ray photoelectron spectroscopy. Since X-ray photoelectron spectroscopy analysis is highly sensitive and able to detect atomic species at the very surface of the hair fibers, receiving signals from an escape depth as shallow as 25 Å, it appeared ideal for the characterization of treatment-induced changes in the hair surface. However, X-ray photoelectron spectroscopy provides an average elemental composition of the hair surface including scale faces and scale edges. The microfluorometric technique, on the other hand, can distinguish progressive delipidation of the scale faces from changes occurring at the broken scale edges. This distinction was shown and characterized in detail by slow speed microfluorometric scanning of the hair surface. Chemical and photochemical oxidative processes at the hair surface result in certain collateral effects. Particularly changes in surface wettability and fiber friction are of significance to the cosmetic chemist because they affect the spreading and wicking of products in hair as well as the managability and the body of hair assemblies. Methods of characterizing these effects are discussed briefly. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=10483
in IFSCC MAGAZINE > Vol. 7, N° 4 (10-11-12/2004) . - p. 299-307[article]Réservation
Réserver ce document
Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité 003885 - Périodique Bibliothèque principale Documentaires Disponible Emulsion polymers : The backbone of waterborne paints / Mamta Kapadia in PAINTINDIA, N° annuel 2002 (2002)
[article]
Titre : Emulsion polymers : The backbone of waterborne paints Type de document : texte imprimé Auteurs : Mamta Kapadia, Auteur Année de publication : 2002 Article en page(s) : p. 85-114 Langues : Anglais (eng) Catégories : Polymères en émulsion
Revêtements (produits chimiques):Peinture (produits chimiques)
Revêtements en phase aqueuse:Peinture en phase aqueuseTags : Use 'Paint film' 'Mechanical properties' Biocide 'Foam inhibitor' Dispersant 'Thickening agent' Adjuvant Filler Pigments 'Chemical composition' 'Physical Polymer Binders Formulation 'Water base paint' Index. décimale : 667.9 Revêtements et enduits Résumé : The purpose of this paper is to review the emulsion technology and identify the system best suited to combine performance with economy in water based paints with special emphasis on economical exterior paints and exterior elastomeric wall coatings. Note de contenu : - Types of emulsion polymers
- Important properties of emulsion polymers : Solids content - pH - Viscosity - Particle size - Glass transition temperature and MFT - Chemical composition
- Selection of emulsion depending on the end use
- Basic ingredients of an emulsion paint : Pigment - Extenders - Thickeners
- Relationship of shear rate to coatings properties : Dispersants - Defoamers - Anti freeze and coalescing agents - Biocides - Results of in-can microbial contamination - Requirement of a biocide for wet state protection - Requirements of a biocide for dry film protection - pH stabilisers
- Elastomeric wall coatings : History - Essential properties of an EWC - Form barrier to liquid water and carbon dioxide gas - Permeable to water vapour they "breathe" - Bridge the cracks - Maintain flexibility and strength over a broad temperature range - Resist dirt pickup - Possess excellent exterior durability
- Surface preparation
- Application
Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=12454
in PAINTINDIA > N° annuel 2002 (2002) . - p. 85-114[article]Réservation
Réserver ce document
Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité 001275 - Périodique Bibliothèque principale Documentaires Disponible Cashew nut shell liquid (CNSL) / Rishabh Resins in PAINTINDIA, N° annuel 2002 (2002)
[article]
Titre : Cashew nut shell liquid (CNSL) : A nature's gift to surface coatings industry Type de document : texte imprimé Auteurs : Rishabh Resins, Auteur ; Chemicals, Auteur Année de publication : 2002 Article en page(s) : p. 115-124 Langues : Anglais (eng) Tags : 'Chemical composition' 'Organic fluid' 'Shell (anatomy)' 'Cashew nut' Binders Formulation Paint 'Coating material' Index. décimale : 667.9 Revêtements et enduits Note de contenu : - Properties of CNSL
- Chemistry of CNSL
- Condensation products
- Other derivatives from CNSL : - Refined oil
- CNSL based finishies
- Surface coating from cardanol
- Pure phenolic resins from cardanol
- Epoxy resins from cardanol
- Cardanol specification and applications
- Oil soluble resins
- Electrical insultating and impregnating varnishes
- Surface coatings and paints
- Lamination industry
- Surface active agent
- Pesticides
- Rubber compoundings
- Azo dyes
- Wax substitutes
- Mineral oil additives
- Adhesives
- Adhesives for plywood
- Food can lacquers
- Brake lining and clutch facings
- Typical formulations for high gloss enamels from cardanol alkyd media
-Paints from cardanol
- Pentadecylophenal from cardanol
- Coatings based on CNSL distillation residue
Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=12455
in PAINTINDIA > N° annuel 2002 (2002) . - p. 115-124[article]Réservation
Réserver ce document
Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité 001275 - Périodique Bibliothèque principale Documentaires Disponible