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VPLIV PROTIMIKROBNE OBDELAVE NA BIORAZGRADLJIVOST CELULOZNIH TEKSTILNIH SUBSTRATOV
Darja Jaušovec, 2010, dissertation

Abstract: V doktorski disertaciji je bil proučen vpliv protimikrobnega sredstva 3-(trimetoksisilil)-propildimetiloktadecil amonijevega klorida (TMPAC) na biorazgradljivost dveh celuloznih substratov. V prvem delu naloge je bila preiskana biorazgradljivost TMPAC obdelane bombažne tkanine v primerjavi z neobdelano ob uporabi vrstične elektronske mikroskopije, FT-IR ATR spektroskopije, diferenčne dinamične kalorimetrije in z določanjem izgube mase. Iz rezultatov je bilo razvidno, da protimikrobno sredstvo TMPAC zmanjšuje stopnjo razgradnje bombažne tkanine, kar je bilo dokazano predvsem z morfološkimi in kemijskimi spremembami med procesom razgradnje. Kemijske spremembe so bile raziskane s pomočjo FT-IR ATR spektroskopije in dokazane zlasti s prisotnostjo amidnih in karboksilnih funkcionalnih skupin. Amidne funkcionalne skupine so nastale kot posledica prisotnosti proteinov nastalih z mikrobno rastjo, medtem, ko so karboksilne funkcionalne skupine nastale kot posledica oksidativne razgradnje celuloze. Dejstvo, da protimikrobno sredstvo TMPAC znižuje stopnjo razgradnje bombažne tkanine je bilo pojasnjeno z močno hidrofobnim značajem TMPAC obdelane površine, kar smo dokazali z večjim stičnim kotom TMPAC obdelanega bombaža v primerjavi z neobdelanim. V drugem delu naloge je bila proučena encimska razgradnja modelnega celuloznega filma obdelanega s protimikrobnim sredstvom TMPAC, v primerjavi z neobdelanim filmom ob uporabi mikroskopije na atomsko silo in elipsometrije. Uporabljene celulaze so bile pridobljene iz gliv Trichoderma viride in Aspergillus niger. Po dodatku encimov k modelnemu celuloznemu filmu, je po začetni adsorpciji encimov na substrat sledila nadaljnja razgradnja celuloze. Encimska razgradnja celuloze je bila dokazana s konstantno izgubo v masi filma ter z ne-monotonim obnašanjem v debelini filma, ki dokazuje, da encimi ne razgrajujejo samo površine filma ampak tudi penetrirajo v film. Učinkovitost uporabljenih celulaz je bila različna in veliko višja stopnja razgradnje je bila opažena pri uporabi celulaze Trichoderma viride. Stopnja razgradnje se je ob uporabi te celulaze očitno znižala, ko je bil celulozni film predhodno obdelan s protimikrobnim sredstvom TMPAC, medtem, ko pa protimikrobno sredstvo ni imelo pomembnega učinka na razgradnjo ob prisotnosti celulaze Aspergillus niger. Dokazano je bilo, da v odvisnosti od tipa celulaze, protimikrobno sredstvo TMPAC zavira encimsko učinkovitost na fazni meji trdno-tekoče. TMPAC povzroča hidrofobnost modelnega celuloznega filma in s tem zavira adsorpcijo encimov na površino substrata.
Keywords: Ključne besede: celuloza, biorazgradljivost, protimikrobno sredstvo, modelni celulozni film, encimska razgradnja, elipsometrija
Published: 02.11.2010; Views: 2269; Downloads: 148
.pdf Full text (11,62 MB)

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Grafting of ethylcellulose microcapsules onto cotton fibres
Roxana Badulescu, Vera Vivod, Darja Jaušovec, Bojana Vončina, 2008, original scientific article

Abstract: In this paper a treatment of cotton with ethylcellulose (EC) microcapsules wasinvestigated. EC microcapsules containing Rosemary oil were obtained by phase separation method. The surface and morphology of microcapsules were characterized by scanning electron microscopy (SEM). Microcapsules with a regular spherical shape in the 10-90 m size range were prepared and grafted onto cotton using the crosslinking reagent 1,2,3,4-butanetetracarboxylic acid (BTCA) in the presence of catalysts. The influence of the two catalysts, cyanamide (CA) and N,N'-dicyclohexylcarbodiimide (DCC) on curing efficiency (grafting) was investigated. SEM and Fourier transform infrared spectroscopy (FT-IR) were used to study the formation of ester bonds between BTCA and hydroxyl groups of cotton and/or hydroxyl groups of EC. When DCC was used as acatalyst, the esterification took place slowly at room temperature. In the case of CA, the cotton was cured at 110 °C for several minutes. After 2 min curing, the microcapsules, which kept their original shape, were bonded to thecotton fibers. Increasing the curing time altered the microcapsule shell. Grafting and crosslinking reactions of the thermofixed EC microcapsules onto cotton were proposed.
Keywords: textiles, chemical modification, cotton fibres, ethylcellulose, microcapsules, BTCA, SEM, FT-IR, grafting
Published: 01.06.2012; Views: 1050; Downloads: 22
URL Link to full text

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[Beta]-cyclodextrin as a retarding reagent in polyacrylonitrile dyeing
Bojana Vončina, Vera Vivod, Darja Jaušovec, 2007, original scientific article

Abstract: ß-Cyclodextrin was tested as a dye complexing agent - as a dye retardant in the dyeing of PAN fibres with cationic dyes. Significant improvement of colouruniformity and some improvements in colour depth were observed when PAN fibres were dyed in the presence of ß-cyclodextrin as compared to dyeing in the presence of a commercial retardant.
Keywords: textile dyeing, cationic dyes, cyclodextrin, polyacrylonitrile fibres, complexation
Published: 01.06.2012; Views: 934; Downloads: 8
URL Link to full text

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