Calorimetric and kinetic analysis of thermal behaviors of chrome-tanned collagen fibers using isoconversional and multivariate non-linear regression methods / Wentao Liu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXII, N° 12 (12/2017)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXII, N° 12 (12/2017) . - p. 399-409 Titre : Calorimetric and kinetic analysis of thermal behaviors of chrome-tanned collagen fibers using isoconversional and multivariate non-linear regression methods Type de document : texte imprimé Auteurs : Wentao Liu, Auteur ; Yuanzhi Zhang, Auteur ; Li Guoying, Auteur Année de publication : 2017 Article en page(s) : p. 399-409 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Calorimétrie Cinétique chimique Collagène Cuirs et peaux -- Analyse Tannage au chrome Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : To further understand the thermal stability of collagen in hide and leather, the thermal denaturation behaviors of chrome-tanned collagen fibers were studied by non-isothermal differential scanning calorimetry (DSC) using isoconversional and multivariate non-linear regression (Multivar-NLR) methods. The differential (Friedman) and the integral (Ozawa-Flynn-Wall) isoconversional methods as well as the Multivar-NLR method showed that the denaturation (or shrinkage) process could be best described by a three-step model, in which a reversible reaction was followed by a rate-limited irreversible step. The simulation of thermal behaviors of collagen at different temperature conditions indicated that the denaturation kinetics could be approximated to a one-step irreversible reaction at low heating rates or temperatures. For the design of new chrome-free tanning systems, which can endow collagen with high enough thermostability, the decrease in the rate of the irreversible denaturation of collagen might be an important criterion as well, besides the increases in the denaturation (or shrinkage) temperature, enthalpy and effective activation energy. Note de contenu : - EXPERIMENTAL : Materials - Preparation of chrome-tanned collagen fibers - Differential scanning calorimetry (DSC)- Kinetic analysis - Isoconversional analysis - Multivar-NLR analysis - Simulation of thermal behaviors of chrome-tanned collagen fibers - RESULTS AND DISCUSSION : Effects of heating rate and chrome-tanning on the thermal denaturation of collagen fibers - Isoconversional kinetic analysis - Multivar-NLR kinetic analysis - Simulation of thermal behaviors of chrome-tanned collagen fibers En ligne : https://drive.google.com/file/d/1PSnXKXyQNIXY8P96zXT0rFmPNHCAYsO4/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=29586 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
19426	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Effect of ionic liquids pretreatment on the extraction of collagen from calf skin / Sicong Liu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIV, N° 10 (10/2019)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXIV, N° 10 (10/2019) . - p. 391-399 Titre : Effect of ionic liquids pretreatment on the extraction of collagen from calf skin Type de document : texte imprimé Auteurs : Sicong Liu, Auteur ; Wentao Liu, Auteur ; Li Guoying, Auteur Année de publication : 2019 Article en page(s) : p. 391-399 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Chimie analytique Collagène Cuirs et peaux de veaux Extraction (chimie) Liquides ioniques Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The use of ionic liquids (ILs) for collagen extraction should be premised of not destroying the triple helix structure of collagen. Herein, the effects of pretreatments by two imidazolium based ILs with different anions, 1-ethyl-methylimidazolium dicyanamide ([EMIM][N(CN)2]) and 1-ethyl-methylimidazolium tetrafluoroborate ([EMIM][BF4]), on the extraction of collagen from calf skins were studied. The dependences of ILs pretreatments on ILs species and concentrations (30%, 50%, and 70% (w/w)) were examined, in terms of the fiber morphology of skins as well as the extraction rate, structural integrity, thermal stability, and aggregation behaviors of collagens. The results of histological analysis and scanning electron microscopy showed that the skin fibers were effectively loosened by the IL s pretreatments. The extraction rate of collagen was improved as the increase of ILs concentration and polarity with the highest value of 28.79%. Moreover, sodium dodecyl sulphatepolyacrylamide gel electrophoresis and Fourier transform infrared spectroscopy confirmed that the structural integrity of collagen was maintained after ILs pretreatments, although the thermal stability of collagen was determined to be slightly decreased by ultra-sensitive differential scanning calorimeter. Finally, pyrene fluorescence analysis and atomic force microscope indicated that the aggregation behavior of collagen was weakened when increasing the ILs concentration and polarity. The green ILs pretreatment of calf skins might be used as an effective approach for the extraction of bioactive collagen with improved yield and purity. Note de contenu : - EXPERIMENTAL : Materials - Ionic liquids pretreatment on NS - Histological analysis - SEM - Extraction of collagen - Extraction rate of collagen - SDS-PAGE - FTIR - Thermal analysis - Fluorescence measurements - AFM - RESULTS AND DISCUSSION : Effect of ILs on calf skin - Extraction rate anaysis - Structural integrity of collagen - Thermal stability of collagen - Aggregation behavior of collagen En ligne : https://drive.google.com/file/d/1IYTryFmWwzS6xJRTho0fxBzDFkzmgrxa/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=33035 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
21208	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Preparation and characterization of alkali-soluble collagen from pigskin shavings / Shuai Shao in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIV, N° 10 (10/2009)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CIV, N° 10 (10/2009) . - p. 344-351 Titre : Preparation and characterization of alkali-soluble collagen from pigskin shavings Type de document : texte imprimé Auteurs : Shuai Shao, Auteur ; Min Zhang, Auteur ; Li Guoying, Auteur ; Wentao Liu, Auteur Année de publication : 2009 Article en page(s) : p. 344-351 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The leather industry discharges large quantities of solid wastes containing high-value native collagen. In this study, the pigskin shavings generated from the shaving of pelts which had been dehydrated with anhydrous sodium sulfate after deliming were pretreated to remove most of salt and fat. Then alkaline treatment method was used to extract collagen from the pigskin shavings. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and circular dichroism (CD) spectra revealed that the alkali-soluble pigskin collagen (ASPC) retained the polypeptide chains and triple helix conformation. The amino acid profiles showed no major deviation from the characteristic collagen composition. Both of the denaturation temperature and the isoelectric point (pI) of ASPC were lower than those of pepsin-solubilized pigskin collagen (PSPC). Scanning electron microscopy showed that ASPC sponges had porous fibrillar network structures, and the pore sizes became larger with the decrease of collagen concentrations and as the pH of the collagen solution approached the pI of ASPC. En ligne : https://drive.google.com/file/d/1oxrpfE-DAUNzUkC1P-_gIBBVEs02RTLj/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=6371 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
011705	-	Périodique	Bibliothèque principale	Documentaires	Disponible

---

1 (1 - 3 / 3)