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31.
Flax fibres sorption properties influenced by different pretreatment processes
Tatjana Kreže, Severina Iskrač, Majda Sfiligoj-Smole, Karin Stana-Kleinschek, Simona Strnad, Darinka Fakin, 2005, izvirni znanstveni članek

Opis: The sorption behavior of raw and treated flax fibers was investigated. This paper presents the effect of conventional pretreatment processes (alkaline, acid) in comparison to environment-friendly enzymatic processes on the sorption ability of flax fibers. Weight-loss, moisture sorption, water retention value and contact angle were determined in order to interpret the pretreatment results. In addition, the influence of the process on the fibers' mechanical properties was studied. The ecological parameters of the treatment wastewaters were analyzed.
Ključne besede: textile fibres, flax, flax fibre properties, pretreatments, sorption properties, mechanical properties, ecological parameters
Objavljeno: 01.06.2012; Ogledov: 1191; Prenosov: 22
URL Povezava na celotno besedilo

32.
The plasma polymerisation process for the deposition of amino-containing film on the poly(ethylene terephthalate) dressing-layer for safe wound-healing
Zdenka Peršin, Adolf Jesih, Karin Stana-Kleinschek, 2012, izvirni znanstveni članek

Opis: This article presents a new approach for preparing antimicrobial layer as a part of multi-composite dressing for safe and efficient wound - healing within a moist environment. Plasma polymerisation using a mixture of argon, ammonia, and hexane gases was used for preparing a thin polymer film on the poly(ethylene terephthalate) (PET) surface. The plasma deposition efficiency, regarding the amount of nitrogen, was evaluated by the Kjeldahl method, whilst the absorption of C.I. Acid Orange 7 dye onto accessible amino groups was monitored within the UV/VIS spectral region. The quantitative amount of charged surface groups was determined by potencometric titration. The results obtained using Kjeldahl method indicated the presence of a substantial amount of nitrogen within the deposited film. Furthermore, mono - azo acidic dye was absorbed onto the polymerised sample, pointing to the formation of an ionic bond between the sulphuric and amino groups. The plasma deposited PET samples resulted in inhibitions regarding all the pathogen microorganisms used, mostly those present in the infected wound.
Ključne besede: plasma polymerisation, argon, ammonia, hexane, poly(ethylene terephthalate), antimicrobial properties, wound dressing
Objavljeno: 01.06.2012; Ogledov: 1127; Prenosov: 61
.pdf Celotno besedilo (75,93 KB)
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33.
Effects of plasma treatment on water sorption in viscose fibres
Miha Devetak, Nejc Skoporc, Martin Rigler, Zdenka Peršin, Irena Drevenšek Olenik, Martin Čopič, Karin Stana-Kleinschek, 2012, izvirni znanstveni članek

Opis: We investigated water sorption in viscose nonwoven fibres manufactured by Tosama d.d. with the surface density of 175 g/m2. A comparison between untreated fibres and by oxygen plasma treated fibres was made using optical polarization microscopy. Plasma treatment was done for 10 minutes at pressure of 75 Pa at current of 250 mA at the power of 500 W. Swelling was characterized by measurements of fibre diameter. Modifications of intensity of the polarized light transmitted through the fibre were measured as a function of time of exposure to water. Characteristic swelling and intensity modification times were resolved for untreated and oxygen plasma treated fibres. The swelling time of oxygen plasma in comparison to untreated plasma is reduced by the factor of 0.54 and intensity change time by the factor of 0.4. From the characteristic swelling and intensity change times it was concluded that oxygen plasma treatment of viscose increases the speed of water sorption.
Ključne besede: plasma treatment, viscose, optical polarization microscopy
Objavljeno: 01.06.2012; Ogledov: 970; Prenosov: 31
.pdf Celotno besedilo (545,63 KB)
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34.
Binding silver nano-particles onto viscose non-woven using different commercial sol-gel procedures
Tanja Pivec, Zdenka Peršin, Silvo Hribernik, Tina Maver, Mitja Kolar, Karin Stana-Kleinschek, 2012, izvirni znanstveni članek

Opis: The paper presents possible solution of Ag binding using commercial sol-gel systems which enable its low release into a wound, providing a good antimicrobial effect on those bacterial cultures that are most likely present in the wound. The influence of different sol-gel systems on the hydrophilic properties of carrier materials and the level of released silver has been studied. The results showed that sol-gel as binding-systems could provide proper hydrophilic properties of material, whilst binding silver strongly enough providing at the same time excellent antimicrobial activity of the treated viscose meterials.
Ključne besede: silver nano-particles, sol-gel, viscose non-woven, silver release, hydrophilicity, antimicrobial properties
Objavljeno: 01.06.2012; Ogledov: 2014; Prenosov: 40
.pdf Celotno besedilo (235,88 KB)
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35.
Heparin adsorption onto model poly(ethylene terephtalate) (PET) surfaces monitored by QCM-D
Aleš Doliška, Simona Strnad, Karin Stana-Kleinschek, 2012, izvirni znanstveni članek

Opis: The adsorption of anticoagulant heparin onto model poly(ethylene terephtalate) (PET) film was monitored using a quartz crystal microbalance with a dissipation unit (QCM-D). Synthetic vascular grafts are usually made from PET, a material with appropriate mechanical properties but moderate haemocompatibility. Therefore anticoagulant heparin is usually used to improve haemocompatibility of PET surfaces. Heparin possesses a high negative charge and as such does not adsorb directly onto hydrophobic PET, which is also negatively charged. To increase heparin adsorption different cationic polymers were investigated as spacers and the highest adsorption was achieved using polyethyleneimine (PEI) as an anchoring agent. The heparin was adsorbed from water solution as well as from phosphate buffer saline (PBS). Heparin dissolved in PBS adsorb better onto PET than heparin from water solution. The results were characterized using Sauerbrey equation and Voigt based viscoelastic model. We found out that heparin adsorbed onto PET formed a thin and rigid film and that Sauerbrey equation is appropriate for characterization of heparin adsorption onto PET.
Ključne besede: poly(ethyleneterephtalate), PET, heparin, QCM-D, haemocompatibility
Objavljeno: 01.06.2012; Ogledov: 1133; Prenosov: 39
.pdf Celotno besedilo (416,79 KB)
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36.
UV polymerization of poly (N-isopropylacrylamide) hydrogel
Manja Kurečič, Majda Sfiligoj-Smole, Karin Stana-Kleinschek, 2012, izvirni znanstveni članek

Opis: This contribution is focused on the determination of polymerization and crosslinking mechanism of poly (N-isopropyl- acralymide) hydrogel and its swelling properties. Hydrogels were synthesized by environmental friendly UV polymerization method, from monomer N-isopropylacrylamide (NIPAM) and crosslinker N,N´-methylenebisacrylamide (BIS) of different concentrations. UV polymerization was performed in an UV chamber using UVA light with the wave length 350 nm. Surface morphology and pore structure analysis was carried out using SEM microscopy. The polymerization and crosslinking mechanism was determined by Fourier Transform Infrared spectroscopy (FT-IR). It was confirmed that crosslinker concentration influences the hydrogel structure and swelling properties. By increasing the crosllinker concentration the hydrogel structure changes from homogen to heterogen and the equilibrium degree of swelling decreases.
Ključne besede: poly (N-isopropylacrylamide) hydrogel, UV polymerization, FTIR, polymerization mechanism, swelling properties, SEM
Objavljeno: 01.06.2012; Ogledov: 1106; Prenosov: 56
.pdf Celotno besedilo (599,31 KB)
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37.
38.
Funkcionalizacija celuloznih vlaken s formulacijo eugenola in hitozana v različnih strukturnih oblikah
Mateja Golčer, 2015, magistrsko delo

Opis: Hitozan je zaradi svoje dokazane varne uporabe primeren tudi za razvoj novih protimikrobnih tekstilnih sistemov, kljub temu pa mu ni moč pripisati lastnosti antioksidativnosti, ki lahko pripomore k hitrejšemu celjenju ran ali razjed. Zaradi tega je smiselno v sistem s hitozanom vključiti katero izmed naravnih spojin z dokazanim antioksidativnim delovanjem. Tem kriterijem ustreza eugenol. Namen tega magistrskega dela je bil razviti formulacijo hitozana v kombinaciji z eugenolom v različnih strukturnih oblikah (raztopina, nanodelci, oborina) za funkcionalizacijo viskoze. Protimikrobna in antioksidativna formulacija bi naj služila kot funkcionalen premaz, prednostno na področju celjenja ran na koži in sluznici v ustni votlini. S stališča različnih strukturnih oblik, ki so ključnega pomena za dostopnost protimikrobnih aminskih skupin in za delež vezanega eugenola v sistem s hitozanom, smo predvideli, da bodo posamezne strukturne oblike različno vplivale na ciljani lastnosti protimikrobnost in antioksidatovnost. V prvi fazi je bila izvedena sinteza nanodelcev (hitozana in eugenola, kapsuliranega v hitozan), ki so bili okarakterizirani z vidika morfologije (SEM) ter velikosti in porazdelitve nanodelcev (DLS). Po opravljeni funkcionalizaciji viskoze s posameznimi strukturnimi oblikami obdelovalne kopeli je bila uporabljena FT-IR spektroskopija za proučitev tipičnih funkcionalnih skupin, potenciometrična titracija, podprta z metodo Acid Orange VII, za proučitev deleža aminskih skupin, ter vrednotenje mikrobioloških lastnosti in antioksidativnega značaja funkcionalizirane viskoze. Desorpcijska kopel je bila ovrednotena na osnovi merjenja pH vodnega ekstrakta. Preostali delež vezanega hitozana po desorpciji je bil, enako kot v primeru funkcionalizacije, proučen z metodo Acid Orange VII. Ugotovljeno je, da različne strukturne oblike hitozana in hitozana v kombinaciji z eugenolom različno vplivajo na protimikrobnost in antioksidativnost funkcionalizirane viskoze. Protimikrobna in antioksidativna formulacija se je izkazala za primeren funkcionalen premaz za razvoj tekstilij za potencialno uporabo v medicini, prednostno na področju celjenja ran ter sluznic.
Ključne besede: viskoza, hitozan, eugenol, hitozanski nanodelci, kapsulacija eugenola, obarjanje hitozana in eugenola, formulacija hitozana in eugenola, protimikrobna funkcionalizacija, antioksidativna funkcionalizacija
Objavljeno: 25.11.2015; Ogledov: 957; Prenosov: 153
.pdf Celotno besedilo (2,74 MB)
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39.
40.
Characterization of amino groups for cotton fibers coated with chitosan
Lidija Fras Zemljič, Simona Strnad, Olivera Šauperl, Karin Stana-Kleinschek, 2009, izvirni znanstveni članek

Opis: The adsorption of chitosan onto cellulose cotton fibers introduces antimicrobial properties, mainly created by the amount and location of amino groups. Therefore, it is important to be able to analyze both parameters, especially in a heterogeneous system, namely cotton fibers coated with chitosan. In this research, three different analytical techniques were applied to determine amino groups of cotton fibers coated with chitosan. The number of positively charged groups was determined indirectly by the spectrophotometric method using Acid Orange 7 dye, and the use of polyelectrolyte titration. In addition, the chemical surface composition regarding non-modified, as well as modified cotton fibers (coated with chitosan), was investigated using X-ray Photoelectron Spectroscopy (XPS). The results from a combination of these methods show that chitosan treatment introduces more than 14 mmol/kg of accessible amino groups onto the cotton fibers. The results were in good agreement with the results of XPS. The use of spectrophotometric and titration methods in combination with XPS appears to be a very useful tool for identifying the formation of amino groups in modified cotton fibers and their surfaces.
Ključne besede: cotton, cellulose, oxidation, chitosan, amino-groups, titration, XPS
Objavljeno: 01.06.2012; Ogledov: 1066; Prenosov: 104
URL Povezava na celotno besedilo

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