Tatjana Kreže

X-ray study of pre-treated regenerated cellulose fibres

Abstract. Regenerated cellulose fibres have had an important role to play in the man-made fibre field. The very special characteristics of different types of regenerated cellulose fibres, e.g. mechanical properties, sorption characteristics, and aesthetics were conditioned by the differences in their fine structure due to fibre formation processes. Additionally, the finishing processes could influence the fibre structure. A study was done of the crystalline structures of a solvent-spun cellulose fibre type (Lenzing Lyocell), made according to the NMMO process, and two conventional cellulosic fibre types, made by the viscose process (Lenzing Viscose and Lenzing Modal). The fibres were pre-treated (bleached and slack mercerised) and structural changes were followed by wide angle and small angle x-ray scattering (WAXS and SAXS), respectively. The periodical structure, determined by long spacing, was nearly the same in all the different types of fibres. A slight increase was observed after the treatment of viscose and modal fibres, but an unpronounced fall of a long period accompanied the pre-treatment of lyocell fibres. Some changes in crystallinity and crystalline orientation occurred due to the treatment conditions. The structural changes were correlated to the iodinesorption and mechanical properties.

Antimicrobial and antioxidant functionalization of viscose fabric using chitosan–curcumin formulations:

The purpose of this work was to develop new additive combinations between chitosan and curcumin in solutions as a fiber-coating. Diverse additive combinations between chitosan and curcumin in solutions were adsorbed onto viscose fabrics in order to reach the essential antimicrobial and antioxidant functionalization for medical textiles. The goal of this paper was to examine the adsorption of these two compounds as an additive formulation on viscose textile material as well as to analyze the desorptions of both substances from the fabric surface. Finally, the antimicrobial and antioxidant properties of viscose fabrics functionalized by chitosan–curcumin formulations were respectively examined. Curcumin as an adsorbate for textiles in combination with chitosan represents an added-value because of its anti-oxidative properties, and showing the potential to enhance existing antimicrobial performance of chitosan when applied using the preferred procedure.

One-shot carboxylation of microcrystalline cellulose in the presence of nitroxyl radicals and sodium periodate

Correction for ‘One-shot carboxylation of microcrystalline cellulose in the presence of nitroxyl radicals and sodium periodate’ by Sergiu Coseri et al., RSC Adv., 2015, 5, 85889–85897.

Correlation between structure and adsorption characteristics of oriented polymers

Abstract In a more or less swollen state the methods by which the fiber structure is determined provide more realistic information about their properties and structure in wet conditions, because of the swelling and alteration of fiber structure. These results, however, of sorption analyses are very rarely in accordance with those obtained from structural analyses. One such ”wet” method is the iodine sorption test. The iodine sorption test was originally proposed by Schwertassek [1] and since then has been constantly modified by other researchers [2–7]. In this presented work the correlation between different structural parameters, iodine sorption (ISV) and conventional sorption analyses (water vapor sorption and water retention power) of polyamide 6 (PA 6) and cellulose fibers was studied. The results demonstrate that the iodine sorption value best correlates with the degree of crystallinity and the perfection of the crystalline phase of both polyamide and cellulose fibers. The correlation is linear.