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Wyszukujesz frazę "carboxymethyl chitosan" wg kryterium: Temat


Wyświetlanie 1-5 z 5
Tytuł:
Synthesis of chitosan and carboxymethyl chitosan hydrogels by electron beam irradiation
Autorzy:
Czechowska-Biskup, Renata
Wach, Radosław
Stojek, Piotr
Kamińska, Martyna
Rosiak, Janusz M.
Ulański, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/1034681.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Tematy:
PEGDA
carboxymethyl chitosan
chitosan
hydrogel
radiation crosslinking
Opis:
Solutions of chitosan (CS) and carboxymethyl chitosan (CMCS) were subjected to irradiation by electron beam in presence of a crosslinking agent (poly(ethylene glycol) diacrylate - PEGDA) in order to produce carboxymethyl chitosan- and chitosan-based hydrogels. PEGDA macromonomer itself undergoes simultaneous polymerization and crosslinking either in neutral water or in acidic medium. Acidic solutions of chitosan of 0.5, 1 and 2% can be effectively crosslinked with PEGDA to form a gel. Although CMCS undergoes radiation-initiated crosslinking only at high concentration in water (over 10%), the presence of PEGDA in solution facilitated hydrogel formation even at lower concentration of CMCS. Formation of CS and CMCS hydrogels required irradiation doses lower than those needed for sterilization, i.e. 25 kGy, in some cases even as low as 200 Gy. Sol-gel analysis revealed relatively high gel fraction of obtained hydrogels, up to 80%, and good swelling ability. Both parameters can be easily controlled by composition of the initial solution and irradiation dose. Possible mechanisms of crosslinking reactions were proposed, involving addition of the polysaccharide macroradicals to a terminal double bond of PEGDA.
Źródło:
Progress on Chemistry and Application of Chitin and its Derivatives; 2016, 21; 27-45
1896-5644
Pojawia się w:
Progress on Chemistry and Application of Chitin and its Derivatives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flotation separation of chalcopyrite from talc using carboxymethyl chitosan as depressant
Autorzy:
Qian, G.
Bo, F.
Danping, Z.
Jujie, G.
Powiązania:
https://bibliotekanauki.pl/articles/110249.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
talc
chalcopyrite
flotation
separation
carboxymethyl chitosan
Opis:
Flotation separation of chalcopyrite from talc using carboxymethyl chitosan as a depressant was studied. Flotation tests indicated that carboxymethyl chitosan had a selective depression effect on talc and the use of carboxymethyl chitosan as the depressant could achieve flotation separation of chalcopyrite from talc at pH 7. Adsorption studies showed that carboxymethyl chitosan only adsorbed on the surface of talc. This was the reason why carboxymethyl chitosan had high depression selectivity for talc. The zeta potential measurements and XPS analysis indicated that carboxymethyl chitosan adsorbed on the talc surface mainly through physical interaction and hydrophobic interaction may be the main driving force.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 1255-1263
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Utilization of N-carboxymethyl chitosan as a selective depressant for talc in flotation of chalcopyrite
Autorzy:
Liu, Cheng
Feng, Qiming
Shi, Qing
Zhang, Wencai
Song, Shaoxian
Powiązania:
https://bibliotekanauki.pl/articles/110512.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
chalcopyrite
talc
flotation separation
N-carboxymethyl chitosan
Opis:
Flotation separation of chalcopyrite from talc is difficult because of the natural hydrophobicity of two minerals. In this work, the flotation separation of chalcopyrite from talc using N-carboxymethyl chitosan as a depressant for talc was studied. The micro-flotation results indicated that the flotation separation of chalcopyrite from talc cannot be realized effectively at pH 9 with low concentration of N-carboxymethyl chitosan, in the presence of calcium ions, talc was more efficiently depressed by N-carboxymethyl chitosan, while the chalcopyrite recovery was not influenced. Contact angle, zeta potential and adsorption results showed that Ca2+ and CaOH+ absorbed on the talc surface and increased the absorption amount of N-carboxymethyl chitosan on the mineral surface, and increased hydrophilicity of talc surface, resulting the selective depression for talc in chalcopyrite flotation.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 1; 108-115
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and potential cytotoxicity evaluation of carboxymethyl chitosan hydrogels
Autorzy:
Kłosiński, Karol K.
Girek, Małgorzata K.
Wach, Radosław A.
Czechowska-Biskup, Renata
Arkuszewski, Piotr T.
Szymański, Paweł B
Pasieka, Zbigniew
Powiązania:
https://bibliotekanauki.pl/articles/1034588.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Tematy:
PEGDA
XTT
carboxymethyl chitosan
cytotoxicity
hydrogel
radiation crosslinking
Opis:
The aim of the research was to employ radiation to produce flexible carboxymethyl chitosan (CMCS) based hydrogels of uniform structure to characterise their swelling properties and cytocompatibility for potential applications as hydrogel wound dressings. CMCS in aqueous solution was irradiated with an electron beam in the presence of a poly(ethylene glycol) diacrylate (PEGDA) macromonomer as a crosslinker, at 12 different compositions, i.e. 3–20% CMCS, 3 and 5% PEGDA. The obtained hydrogels were subjected to sol–gel analysis. The amount of insoluble fraction (up to 100%) rose with an increase in the PEGDA/polysaccharide ratio. Moreover, the equilibrium degree of swelling, ca. 15 to 200 g of water per g of gel, which was higher for lower content of crosslinker, decreased with the delivered dose, which was associated with an increase in crosslinking density. The in vitro XTT cell viability assay (murine fibroblasts, L929 cell line) showed no significant cytotoxicity of CMCS gels.
Źródło:
Progress on Chemistry and Application of Chitin and its Derivatives; 2017, 22; 82-96
1896-5644
Pojawia się w:
Progress on Chemistry and Application of Chitin and its Derivatives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Functional three-component polymeric biocomposites for the treatment of bedsores
Autorzy:
Wiśniewska-Wrona, Maria
El Fray, Mirosława
Powiązania:
https://bibliotekanauki.pl/articles/1034423.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Tematy:
Chitosan
FTIR
NMR
alginate
carboxymethyl cellulose
dressing DSC
Opis:
Presented here are the results of investigations into the preparation of three-component dressing materials from various biopolymers in the form of a single-layer film which is suitable as a carrier for pain-relieving (lidocaine) and bacteriostatic (sulphanilamid) therapeutic agents. Physical-chemical, biological and usable properties of the prepared materials were tested and assessed. The amount of added active substance was adopted based on the dose recommended by the Polish Pharmacopeia for external medicinal preparations. Antibacterial activity against gram (-) Escherichia coli and gram (+) Staphylococcus aureus was assessed in some of the biocomposites by quantitative methods. The cytotoxic action in direct contact with the mouse fibroblast NCTC clone 929 was also estimated. Thermal analysis (DSC), infrared spectrophotometry (FTIR) and nuclear magnetic resonance spectroscopy were employed to investigate the impact of the variable contents of chitosan, alginate, carboxymethyl cellulose (CMC), and the active substance upon the chemical- and phase-structure of the prepared three-component polymeric biocomposites. It was found that the quantitative composition of the biocomposites and the additive of active substances lidocaine and sulphanilamide exert a vital impact upon their physical-mechanical and usable properties (imbibition, absorption). Investigations into the release of the medicinal substance from the investigated biocomposites to an acceptor fluid led to the conclusion that the kinetics of the process may be described by a complex first order rate equation with two exponential functions.
Źródło:
Progress on Chemistry and Application of Chitin and its Derivatives; 2018, 23; 185-206
1896-5644
Pojawia się w:
Progress on Chemistry and Application of Chitin and its Derivatives
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-5 z 5

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