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The characterisation of surface area and surface heterogeneity profiles of hair by inverse gas chromatography / Frank Thielmann in IFSCC MAGAZINE, Vol. 5, N° 3 (07-08-09/2002)
[article]
Titre : The characterisation of surface area and surface heterogeneity profiles of hair by inverse gas chromatography Type de document : texte imprimé Auteurs : Frank Thielmann, Auteur ; Duncan Pearce, Auteur ; Yash K. Kamath, Auteur Année de publication : 2002 Article en page(s) : p. 189-193 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Caractérisation
Cheveux -- analyse
Cheveux -- Anatomie
Chromatographie en phase inverseLa chromatographie en phase inverse est un type de chromatographie. La base d'une phase inverse est une phase normale sur laquelle des chaînes alkyles (ou autres selon la polarité recherchée) ont été greffées au niveau des groupes silanols (end-capping).
En général, la phase stationnaire est majoritairement composée de petites particules de silice sur lesquelles on a greffé des fonctions chimiques, le plus souvent de chaines alkyles à 8 ou 18 atomes de carbones. Les fonctions silanols (Si-OH) qui subsistent engendrent des interactions hydrophiles parasites, qui rendent les résultats non reproductibles surtout pour les molécules basiques. Pour éviter cela, la surface de la silice est généralement recouverte par une fonction méthyle et les fonctions silanols ne sont plus libres mais sous la forme (Si-O-CH3), c'est cette étape que l'on appelle "end-capping". Les fonctions chimiques utilisées pour le "end-capping" peuvent toutefois être de nature très diverses et les colonnes de dernières générations résistant à des pH extrêmes sont généralement "end-capped" avec des fonctions proposant une plus grande gène stérique, tel que le tert-butyle (Si-O-C(CH3)3).
Selon le taux de greffage, on obtient une plus ou moins grande résolution.
Cette phase est dite "inverse" car de polaire et hydrophile (sans les "greffes"), la phase devient apolaire et hydrophobe.
Conditionneurs (cosmétique)
Energie de surface
Oxydoréduction
Traitement chimiqueIndex. décimale : 668.5 Parfums et cosmétiques Résumé : In the present paper the surface areas and adsorption potential distributions of nine different hair samples have been determined by Inverse Gas Chromatography (IGC). These samples were subjected to chemical grooming procedures followed by conditioner treatments both of which alter the surface energy of hair. Since surface energy affects the strength of adsorption of molecules on the surface, this can be characterized by determining the adsorption potential distribution of the surface of hair using specific probe molecules. The distribution function reflects the energetic heterogeneity profile of a surface and provides interesting information on the nature and population of surfaces sites of different interaction energy. In this study IGC is shown to be a fast and accurate technique for the determination of these distribution functions. The data can be used to explain the adsorption behavior of various surfactants and conditioners from different formulations and how these surface deposits alter the energy of the fiber surface. The results indicate that chemical reactions such as bleaching (oxidation) and perming (reduction) increase the surface energy of the fiber by increasing the number of acidic anionic groups in the surface of hair and consequently increase the adsorption potential of the surface. The energy of the resulting surface depends on the orientation of adsorbed molecules. For example, coverage of anionic surface by cationic conditioner molecules can result in a decrease in the surface energy because of the projection of lipid chain of the surfactant away from the surface. Although IGC has been used in the study of surface energetics of polymers and fibers, its use in unraveling the surface energetics of hair, especially when hair is subjected to damaging grooming treatments and treatments which alleviate such damage, is novel. This is especially true of bleaching and perming which introduce acidic sites in the hair and treatment with surfactants and conditioners which adsorb on these sites and leave a protective residue in the hair. These residues alter the surface energy of hair. The changes that occur on the outer surface can be determined by wettability measurements. However, the changes that occur by alyerations in porosity (as in perming) and penetration of low molecular weight materials such as surfactants and humectants, and their adsoprtion on the internal surface of hair can be determined only by methods like IGC. The method can be very sensitive depending on the selection of appropriate probe molecules. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=10646
in IFSCC MAGAZINE > Vol. 5, N° 3 (07-08-09/2002) . - p. 189-193[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 003875 - Périodique Bibliothèque principale Documentaires Disponible The effect of alkali treatment and addition of microcrystalline cellulose (MCC) on physical and tensile properties of ramie/polyester laminated composites / Jamasri in REVUE DES COMPOSITES ET DES MATERIAUX AVANCES, Vol. 32, N° 2 (04/2022)
[article]
Titre : The effect of alkali treatment and addition of microcrystalline cellulose (MCC) on physical and tensile properties of ramie/polyester laminated composites Type de document : texte imprimé Auteurs : Jamasri, Auteur ; Ferriawan Yudhanto, Auteur Année de publication : 2022 Article en page(s) : p. 77-84 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cellulose La cellulose est un glucide constitué d'une chaîne linéaire de molécules de D-Glucose (entre 200 et 14 000) et principal constituant des végétaux et en particulier de la paroi de leurs cellules.
Composites à fibres végétales -- Propriétés mécaniques
Elasticité
Essais dynamiques
Fibres de ramie
Polyesters
Stratifiés -- Propriétés mécaniques
Structure cristalline (solide)
Traitement chimiqueIndex. décimale : 668.4 Plastiques, vinyles Résumé : The aim of this research is to investigate the effect of alkali treatment of ramie fibers and addition of MCC on the properties of ramie/polyester laminated composites. The alkali treatment was performed using NaOH solution at a room temperature. The laminated composites was manufactured using a vacuum infusion method for three layers of treated woven ramie fibers in the polyester matrix. The MCC (microcrystalline cellulose) powder 0.5 wt.% was added into the polyester resin and then mixed by a mechanical stirrer at a rotation speed of 350 rpm for 5 minutes. The physical characterization was evaluated using FTIR, XRD, and SEM methods. The tensile test of a single fiber and laminated composites was carried out according to the ASTM D3379 and ASTM D3039, respectively. The experimental results show that the XRD of treated fiber with 5 wt.% NaOH solution has the highest crystallinity index of 66.3%. It impacts the increase of tensile strength and elastic modulus of single ramie fiber by 18% and 55%, respectively. The addition of MCC into the polyester matrix of laminated composite can increase the tensile strength and elastic modulus by 18% and 21%, respectively, compared to the untreated laminated composite. In addition, the treated fibers laminated composite can improve the adhesion and chemical bonding between fibers and polyester as a matrix. The addition of MCC filler may prevent the initial propagation of cracks on interlaminar surfaces of laminated composite. Note de contenu : - MATERIALS AND METHODS : Alkali treatments - X-Ray diffraction testFTIR (Fourier Transform Infra-Red) test - SEM (Scanning Electron Microscope) - Tensile test of a single ramie fiber Ramie/polyester laminate composite fabrication - Tensile test of laminated composite
- RESULTS AND DISCUSSION : X-Ray diffraction analysis - FTIR (Fourier Transform Infrared) analysis of ramie fibers - Tensile strength of single ramie fiber - Tensile strength of ramie/polyester laminate composites (LC) - Photo SEM of ramie/polyester laminate composite after tensile testDOI : https://doi.org/10.18280/rcma.320204 En ligne : https://www.iieta.org/download/file/fid/74280 Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37700
in REVUE DES COMPOSITES ET DES MATERIAUX AVANCES > Vol. 32, N° 2 (04/2022) . - p. 77-84[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 23632 - Périodique Bibliothèque principale Documentaires Disponible The effect of chemical treatment on the mechanical and thermal properties of composite materials based on clay reinforced with sawdust / Fadhila Mouissa in MATERIAUX & TECHNIQUES, Vol. 109, N° 1 (2021)
[article]
Titre : The effect of chemical treatment on the mechanical and thermal properties of composite materials based on clay reinforced with sawdust Type de document : texte imprimé Auteurs : Fadhila Mouissa, Auteur ; Azzedine Benyahia, Auteur ; Mokhtar Djehiche, Auteur ; Kamel Belmokre, Auteur ; Nadir Deghfel, Auteur ; Ali Redjem, Auteur ; Zine El Abidine Rahmouni, Auteur Année de publication : 2021 Article en page(s) : 11 p. Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Argile
Composites à fibres végétales -- Propriétés mécaniques
Sciure de bois
Thermocinétique
Traitement chimiqueIndex. décimale : 620.13 Matériaux de construction : pierre, ciment, béton, liants de Résumé : This study investigates the effect of the chemical treatment of sawdust on the mechanical and thermal properties of a clay composite reinforced with sawdust in variable mass proportions: 0.5, 1, 1.5, 2 and 2.5%, intended for use as brick in rural houses in desert areas. The sawdust was chemically treated with 5 wt% NaOH and 0.01 wt% KMnO4 solutions. The mechanical test results of the reinforced composite with alkali-treated sawdust show an increase in flexural and compression strength, reaching a maximum value of 0.89 and 4.85 MPa, respectively. However, the thermal test results show a significant decrease in the thermal conductivity of the sawdust-reinforced composite. The best result recorded is that of untreated sawdust, which has a value of 0.37 (W.m−1.K−1) compared to the one reinforced with treated sawdust. Note de contenu : - MATERIALS AND METHODS : Lime - Water - Clay preparation procedures - Chemical treatments of sawdust - Preparation of composites - Measuring apparatuses
- RESULTS AND DISCUSSION : Particle size analysis of clay - Basic chemical composition of clay - X-ray diffractions - Infrared spectroscopy analysis - SEM analysis - Mechanical tests - Thermal properties
- Table 1 : Chemical compositions of the lime
- Table 2 : Chemical composition of the mixing water
- Table 3 : List of abbreviations used
- Table 4 : Chemical compositions of the clayRéférence de l'article : 101 DOI : https://doi.org/10.1051/mattech/2021013 En ligne : https://www.mattech-journal.org/articles/mattech/pdf/2021/01/mt200032.pdf Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=36125
in MATERIAUX & TECHNIQUES > Vol. 109, N° 1 (2021) . - 11 p.[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 22873 - Périodique Bibliothèque principale Documentaires Disponible The efficiency of various treatments in protecting wood surfaces against weathering / V. Jirous-Rajkovic in SURFACE COATINGS INTERNATIONAL. PART B : COATINGS TRANSACTIONS, Vol. 87, B1 (02/2004)
[article]
Titre : The efficiency of various treatments in protecting wood surfaces against weathering Type de document : texte imprimé Auteurs : V. Jirous-Rajkovic, Auteur ; D. Radovan, Auteur ; A. Bogner, Auteur Année de publication : 2004 Article en page(s) : p. 15-19 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Bois -- Détérioration
Bois -- Revêtements protecteurs
Bois -- Vernis
Bois extérieurs
Essais accélérés (technologie)
Essais d'adhésion
Lasures
Nitrate de fer
Photostabilisants
Résistance aux conditions climatiques
Revêtements organiques
Stabilisant à la lumière de type amine encombrée
Traitement chimiqueIndex. décimale : 667.9 Revêtements et enduits Résumé : Wood exposed to the outdoors undergoes photo-oxidative degradation in a natural weathering process.
The efficacy of various treatments for the protection of wood surfaces from weathering elements (ultraviolet radiation and water) was investigated by using the measurements of the changes in adhesion on fir and oak samples after their exposure to natural climatic conditions and after accelerated weathering.
The most efficacious of the six UV-protective treatments proved to be the treatment of the wood surfaces with a semi-transparent stain, followed by treatments with a transparent wood stain containing two types of photostabilisers. The stabilisation of the wood surfaces by ferric nitrate did not improve the performance of the wood stain used.Note de contenu : - Wood samples
- Chemical treatments
- Coatings
- Accelerated weathering
- Natural weathering
- Adhesion testing
- Table 1 : Sample codes and description of the treatments
- Table 2 : Mean adhesive strength (MPa) and standard deviations of samples after QUV exposure
- Table 3 : Mean adhesive strength (MPa) and standard deviations of samples after natural exposureDOI : 10.1007/BF02699559 En ligne : https://link.springer.com/content/pdf/10.1007/BF02699559.pdf Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=5477
in SURFACE COATINGS INTERNATIONAL. PART B : COATINGS TRANSACTIONS > Vol. 87, B1 (02/2004) . - p. 15-19[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 000392 - Périodique Bibliothèque principale Documentaires Disponible Waterproofing of sole leather / P. L. Muthiah in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 54, N° 5 (05/1970)
[article]
Titre : Waterproofing of sole leather Type de document : texte imprimé Auteurs : P. L. Muthiah, Auteur ; V. Mohanaradhakrishnan, Auteur Année de publication : 1970 Article en page(s) : p. 183-201 Langues : Anglais (eng) Catégories : Alun
Couleur
Cuir
Décapage
Essais (technologie)
Humidité -- Absorption:Eau -- Absorption
Imperméabilisation
Produits de nourriture du cuir
Retannage
Semelles
Traitement chimiqueIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : The continued and increasing competition from synthetic materials in ail branches of leather industry emphasises the importance of investigations concerned with the improvement of water resistance of leather. Literature survey indicates that a wide variety of materials and methods have been used for improving the water resistance of leather. A suitable material for this purpose demands the following qualities : (a) with a minimum quantity of the material considerable increase in water resistance ; (b) uniform effect throughout the thick-ness of the leather, otherwise the effect will be lost in short time ; (c) preservation of the air and water vapour permeability ; (d) retention of the qualities such as : grip, flexibility and colour ; (e) non-attainment of thermoplastic properties, i.e. the leather must be soft and flexible in a cold climate and should not be sticky at high temperature ; (f) the method of application must be simple ; (g) the materials must be easily available in the market in large quantities and must be cheap.
In order to find a suitable waterproofing material for vegetable tanned sole leather, a preliminary study was undertaken using various waterproofing materials and methods, viz. impregnation with different materials, retanning with zirconium, chromium and aluminium salts and basic aluminium sulphate treatment. Preparation of crust vegetable sole leather and the sampling method were the same as described earlier. The well known Kubelka's apparatus was used for determining the water absorption of leathers.Note de contenu : - Impregnation with different materials
- Retanning with zirconium, chromium and aluminium salts : Studies using basic aluminium sulphate - Studies on the improvements - Neutralisation of colour - Chemical treatments - Field tests
- Results and discussion : Effect of impregnation - Retanning - Studies using basic aluminium sulphate - Effect of oiling before alum treatment - Effect of oiling after alum treatment - Mechanism of waterproofing
- Studies on the improvement of colour
- Field tests
- Table 1 : Effect of waterproofing with various materials
- Table 2 : Effect of retanning and alum dipping
- Table 3 : Effect of stripping
- Table 4 : Effect of re-use of alum liquor
- Table 5 : Effect of oiling
- Table 6 : Colour of the leathers, processed by various methods
- Table 7 : Water absorption of leathers after different treatmentsEn ligne : https://drive.google.com/file/d/1j4LfXSuut-MMCX_O2ejEjIaa-jVTxilK/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37008
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 54, N° 5 (05/1970) . - p. 183-201[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 007082 - Périodique Bibliothèque principale Documentaires Disponible