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1.
The influence of increased cross-linker chain length in thermosensitive microspheres on potential sun-protection activity
Witold Musiał, Vanja Kokol, Bojana Vončina, 2010, izvirni znanstveni članek

Opis: The sun protection should involve substances with protecting activity against both UVB and UVA radiation. In this research the evaluation of thermosensitive microspheres as potential molecules for sunscreen formulations was approached, using modified Boots star rating system. The microspheres, thermosensitive N-isopropylacrylamide derivatives, have potential protecting activity against UV radiation. The MX and DX microspheres, with ethylene glycol dimethacrylate and diethylene glycol dimethacrylate crosslinker respectively, due to theirs thermosensitivity exhibit increase in protecting activity against UV radiation when heated to 45°C. The MX microspheres have higher increase in terms of UV absorbance, comparing to DX microspheres, when heated in the 25°C to 45°C range. Studied microspheres have high potential forapplication as components of sun-screens used in elevated temperatures.
Ključne besede: thermosensitive microspheres, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, ultraviolet radiation, sun-screen
Objavljeno: 31.05.2012; Ogledov: 947; Prenosov: 14
URL Povezava na celotno besedilo

2.
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: 1091; Prenosov: 58
.pdf Celotno besedilo (75,93 KB)
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3.
Tuning of poly(ethylene terephtalate)(PET)surface properties by oxygen plasma treatment
Aleš Doliška, Metod Kolar, 2011, izvirni znanstveni članek

Opis: Modification of surface properties of poly(ethyleneterephtalate) (PET) thin films by treatment with weakly ionized oxygen plasma was studied by contact angles of water and diiodomethane (DIM) drops. Samples were exposed to oxygen plasma with the ion density of 5 x 1015/m[sup]3 and the neutral oxygen atom density of 3 x 1021/m[sup]3. Just after the treatment they were characterized by contact angle measurements. Results showed a quick decrease of the water contact angle in the first few seconds of plasma treatment, while prolonged treatment did not cause any substantiated modification. The contact angles of DIM, on the other hand, remained rather constant for the first several secondsof plasma treatment, and increased after prolonged treatment. It was found that the dispersion component of the surface free energy decreased with increasing treatment time, while the polar component increased with treatment time. The results were explained by surface functionalization as well as by roughness effects.
Ključne besede: poly(ethylene terephtalante), PET, oxygen plasma, contact angle, hydrophilic, functionalization
Objavljeno: 01.06.2012; Ogledov: 1137; Prenosov: 22
.pdf Celotno besedilo (329,87 KB)
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4.
5.
Microvoid system in fibres
Majda Sfiligoj-Smole, Diana Gregor-Svetec, 2002, izvirni znanstveni članek

Opis: The macrovoid system of poly(ethylene terephthalate) (PET) and poly(propylene) (PP) fibres was studied by small-angle x-ray scattering (SAXS). Commercial PET textile fibres were treated in different media and the influence on fibre homogeneity was followd by SAXS. PP technical fibres were manufactured on a laboratory spin-drawing device and subsequently drawn at different drawing conditions on a laboratory drawing device. The influence of drawing on the pore system was followed.
Ključne besede: textile industry, textile fibres, morphology, structure, investigations, SAXS, poly(ethylene terephtalate), PET, poly(propylene), PP, voids, microvoids
Objavljeno: 10.07.2015; Ogledov: 589; Prenosov: 45
.pdf Celotno besedilo (284,24 KB)
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6.
Zastrupitev z etilenglikolom
Nina Hojs, Robert Ekart, Franc Svenšek, 2011, strokovni članek

Opis: Zastrupitve z etilenglikolom so dokaj redke. Etilenglikol je sam po sebi malo toksičen, hudo zastrupitev povzročajo predvsem njegovi presnovni produkti. Prikazani primer obravnava značilno klinično sliko (nevrološka, kardiopulmonalna in ledvična faza) in laboratorijske rezultate (povišana serumska osmolalnost, povišana osmolalna vrzel, metabolična acidoza s povišano anionsko vrzeljo, kristali kalcijevega oksalata v urinu) ob zastrupitvi z etilenglikolom. Hitra prepoznava je nujna, saj sta obolevnost in smrtnost po zastrupitvi visoki. Zdravljenje vključuje vzdrževanje dihalne poti, dihanja in krvnega obtoka, infuzijo bikarbonata, dajanje antidota (etanol, fomepizol), hemodializo, včasih tudi zdravljenje s kofaktorji presnove etilenglikola (tiamin, piridoksin, magnezij).
Ključne besede: Acid-Base Equilibrium, Acido-bazno ravnotežje, diagnosis, Diagnostika, Emergency Treatment, Ethylene Glycol, Etilenglikol, klinična slika, Nujno ukrepanje, Osmolar Concentration, Osmolarna koncentracija, poisoning, therapy, Zastrupitve, Zdravljenje
Objavljeno: 30.12.2015; Ogledov: 1314; Prenosov: 60
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7.
Covalent binding of heparin to functionalized PET materials for improved haemocompatibility
Metod Kolar, Miran Mozetič, Karin Stana-Kleinschek, Mirjam Fröhlich, Boris Turk, Alenka Vesel, 2015, izvirni znanstveni članek

Opis: The hemocompatibility of vascular grafts made from poly(ethylene terephthalate) (PET) is insufficient due to the rapid adhesion and activation of blood platelets that occur upon incubation with whole blood. PET polymer was treated with NHx radicals created by passing ammonia through gaseous plasma formed by a microwave discharge, which allowed for functionalization with amino groups. X-ray photoelectron spectroscopy characterization using derivatization with 4-chlorobenzaldehyde indicated that approximately 4% of the –NH2 groups were associated with the PET surface after treatment with the gaseous radicals. The functionalized polymers were coated with an ultra-thin layer of heparin and incubated with fresh blood. The free-hemoglobin technique, which is based on the haemolysis of erythrocytes, indicated improved hemocompatibility, which was confirmed by imaging the samples using confocal optical microscopy. A significant decrease in number of adhered platelets was observed on such samples. Proliferation of both human umbilical vein endothelial cells and human microvascular endothelial cells was enhanced on treated polymers, especially after a few hours of cell seeding. Thus, the technique represents a promising substitute for wet-chemical modification of PET materials prior to coating with heparin.
Ključne besede: poly(ethylene terephthalate), vascular graft, biocompatibility, heparin, plasma, functionalization, haemolysis, platelet adhesion, endothelization
Objavljeno: 21.06.2017; Ogledov: 349; Prenosov: 180
.pdf Celotno besedilo (1,70 MB)
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8.
Modification of PET-polymer surface by nitrogen plasma
Rok Zaplotnik, Metod Kolar, Aleš Doliška, Karin Stana-Kleinschek, 2011, izvirni znanstveni članek

Opis: Low pressure weakly nitrogen plasma was applied for incorporation of nitrogen-containing functional groups onto poly(ethylene terephthalate) - PET polymer. Nitrogen plasma was created in an electrode-less radiofrequency discharge at the nominal power of 200 W and the frequency of 27.12 MHz. Nitrogen molecules entered the discharge region were highly excited, partially dissociated and weakly ionized. Transformation into the state of plasma allowed for creation of chemically reactive particles with a high potential energy while the kinetic energy remained close to the value typical for room temperature. The chemical reactivity allowed for rapid functionalization with nitrogen-rich functional groups. The appearance of these groups was monitored by X-ray photoelectron spectroscopy - XPS. The polymer surface was quickly saturated with nitrogen indicating that the modification was limited to an extremely thin surface film.
Ključne besede: poly(ethylene terephthalate), nitrogen plasma, surface modification, functional groups, X-ray photoelectron spectroscopy
Objavljeno: 17.03.2017; Ogledov: 325; Prenosov: 61
.pdf Celotno besedilo (150,48 KB)
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