| | SLO | ENG | Cookies and privacy

Bigger font | Smaller font

Search the digital library catalog Help

Query: search in
search in
search in
search in
* old and bologna study programme

Options:
  Reset


1 - 3 / 3
First pagePrevious page1Next pageLast page
1.
Influence of the temperature on the efficiency of cellulose treatment using copolymer chitosan-eugenol
Olivera Šauperl, Jasna Tompa, Julija Volmajer Valh, 2014, original scientific article

Abstract: In order to achieve effective antimicrobial protection of textile materials against microorganisms, a natural compound called chitosan has become very interesting. In regard to the antimicrobial protection of textile materials, functionalization with chitosan does not affect some other properties, such as anti-oxidative or any other action. For this reason, it seems appropriate for chitosan to be combined with any natural antimicrobial active compound, such as eugenol, an extract of clove oil. During this research viscose as a representative of cellulose fibers was used, because it can be functionalized relatively easily. In terms of functionalization, the drying temperature of viscose, after antimicrobial compound application onto substrate, as well as the successful synthesis of copolymer chitosan/eugenol is also important. FTIR spectroscopy was used to evaluate the efficiency of synthesizing a chitosan/eugenol graft copolymer. The spectrophotometric method Acid Orange 7 was chosen as a means for determining the proportion of available antimicrobial active amino groups. In addition, microbiological testing of selected pathogenic micro-organisms was also performed. The results were compared with the results for viscose functionalized by a 1% solution of chitosan.
Keywords: chitosan, eugenol, functionalization, viscose, FTIR spectroscopy, Acid orange 7, antimicrobial
Published: 02.08.2017; Views: 571; Downloads: 332
.pdf Full text (233,00 KB)
This document has many files! More...

2.
Chemical binding of chitosan and chitosan nanoparticles onto oxidized cellulose
Olivera Šauperl, Mirjana Kostić, Jovana Milanovic, Lidija Fras Zemljič, 2015, original scientific article

Abstract: The aim of this study was to analyze binding of chitosan and chitosan nanoparticles onto cellulose via oxidized cellulose. The ability of chitosan and chitosan nanoparticles to be adsorbed onto surfaces was determined by the use of the XPS spectroscopy which provided information about chemical composition of the fiber surface. On the other hand, the gravimetric method was also used by which the amount of chitosan and chitosan nanoparticles bounded onto surface was calculated based on the difference in masses before and after functionalization. The most important was to study the influence of aldehyde groups on the stability of chitosan binding onto cellulose. Thus, desorption of chitosan/chitosan nanoparticles from the fiber surfaces was evaluated by the presence of total nitrogen (TN) in desorption bath as well as by polyelectrolyte titrations. Together with these two methods, desorption was evaluated also by gravimetric method, where the extent of desorption was evaluated on the basis of the differences in the masses of fibers before and after desorption. It is concluded that the chitosan and chitosan nanoparticles are more efficiently bounded onto oxidized cellulose in comparison with the non-oxidized (reference) ones. Despite the binding of the positively-charged amino groups with the negative groups of cellulose and consequently smaller amount of available/residual protonated amino groups that are responsible for bioactivity, such functionalized fibers are still specifically antimicrobial.
Keywords: cellulose, oxidized cellulose, oxidation, chitosan, chitosan nanoparticles, FTIR, XPS, antimicrobial functionalization
Published: 02.08.2017; Views: 701; Downloads: 380
.pdf Full text (144,32 KB)
This document has many files! More...

3.
Adsorption and antibacterial activity of soluble and precipitated chitosan on cellulose viscose fibers
Lidija Fras Zemljič, Tijana Ristić, Tina Tkavc, 2012, original scientific article

Abstract: The aim and novelty of this work was to compare the adsorption of totally-soluble chitosan (acidic solution) against the adsorption of precipitated chitosan, onto cellulose fibers. The influences of both these chitosan-adsorption procedures on a final amino groupćs content in functionalized cellulose fibers were studied, using potentiometric titration and the conventional spectrophotometric C.I. Acid Orange 7 method. Surface modification and adsorption of chitosan were, in addition, monitored by determining XPS spectra. The antimicrobial activities of both chitosan- functionalised cellulose fibers were examined, in regard to pathogen bacteria and fungus.
Keywords: functionalized viscose, chitosan solution, precipitates, potentiometric titration, spectrophotometry, antimicrobial activity
Published: 01.06.2012; Views: 1709; Downloads: 326
.pdf Full text (372,02 KB)
This document has many files! More...

Search done in 0.14 sec.
Back to top
Logos of partners University of Maribor University of Ljubljana University of Primorska University of Nova Gorica