Darka Mihailović

Functionalization of PET fabrics by corona and nano silver

In this work, the antibacterial and other properties of polyester fabrics previously functionalized by corona and/or silver nano particles have been studied. Corona air plasma was used as a pretreatment of raw, washed and washed-thermostabilized polyester fabrics to increase the adhesion of nano silver particles resulting in an excellent antibacterial effect. X-ray photoelectron spectroscopy was applied to analyze the surface composition and chemical bonding of the surface atoms on untreated and treated fabrics. The surface morphological changes of polyester fibers were observed by scanning electron microscopy (SEM). The quantity of silver on the polyester fabrics was determined by the use of the inductively coupled plasma-atomic emission spectrometry method. The antimicrobial properties of functionalized polyester fabrics were tested according to American Society for Testing and Materials ASTM Designation: E 2149-01. Additionally, the dyeing of polyester fabrics with selected disperse dye as well as capillary action tests were performed to confirm the chemical and morphological changes of polyester fibers after corona treatment. Considerable differences in surface composition were found between the raw and washed or washed-thermostabilized fabrics. The surface of raw fabrics is richer in carbon and the concentrations of the C—O and O—C=O groups are lower than on the other samples. An opposite effect is observed for washed and washed thermostabilized fabrics. SEM analyses show that the plasma treatment also affects the surface morphology. The chemical surface composition and morphology are highly related to the hydrophobicity and hydrophylicity, and the achievement of better nano silver adhesion and enhanced dyeing and antimicrobial properties of differently prepared corona plasma-treated polyester fabrics. Therefore, corona air-treated raw polyester fabrics demonstrated optimum antimicrobial properties due to the excellent adhesion of nano silver.

Improved properties of oxygen and argon RF plasma-activated polyester fabrics loaded with TiO2 nanoparticles.

The potentials of low-pressure capacitively coupled RF oxygen and argon plasmas for the activation of polyester fibers surface that can enhance the deposition of colloidal TiO(2) nanoparticles were discussed. SEM and XPS analysis confirmed the plasma-induced morphological and chemical changes on the surface of polyester fibers. Oxygen and argon plasma pretreated polyester fabrics loaded with TiO(2) nanoparticles provided maximum reduction of Gram-negative bacteria E. coli and UV blocking. The self-cleaning effects tested on blueberry juice stains and photodegradation of methylene blue in aqueous solution proved excellent photocatalytic activity of TiO(2) nanoparticles deposited onto fiber surface. Although both plasmas significantly contributed to overall improvement of properties of such nanocomposite textile material, oxygen plasma treatment, in particular, enhanced the deposition of colloidal TiO(2) nanoparticles and thus ensured superior effects.

Recycled wool‐based nonwoven material for decolorisation of dyehouse effluents

Purpose – The purpose of this paper is to investigate the possible application of recycled wool‐based nonwoven material (RWNM) for removal of different dyes that are used in textile dye houses.Design/methodology/approach – The sorption kinetics, the influence of initial dye concentration, pH and temperature are analyzed. Basic, reactive, direct and metal complex dyes are studied.Findings – The sorption properties are highly influenced by the type of the dye owing to differences in their chemical structure and thus, the mechanism of binding to wool. Modification of material with chitosan and hydrogen peroxide improves the sorption capacities and sorption rates but no general trend can be established. Consequently, the sorption behaviour is analyzed separately for each type of the dye.Originality/value – The results indicate that RWNM can be used as an efficient, low‐cost sorbent for decolorisation of effluents.

The Study of Sorption of Toxic Basic Dyes from Aqueous Solutions on H2O 2 Treated Recycled Wool-based Nonwoven Material and Related Toxicity Analysis

The aim of this study was to investigate the potential use of recycled wool-based nonwoven material for removal of basic dyes C.I. Basic Yellow 28 and C.I. Basic Red 46 from aqueous solutions. To improve the sorption properties, the recycled wool-based nonwoven material was treated with hydrogen peroxide. The sorption capacity, the sorption kinetics, and the influence of initial dye concentration and pH on the sorption were studied. The acute toxicity of dyes was evaluated using a ToxAlert® 100 biological test, which is based on inhibition of the bioluminescence of Vibrio fischeri . The percent of inhibition (%I) before and after the sorption, 50 % effective concentration (EC 50) and toxicity units (TU) were determined. The results indicated that recycled wool-based nonwoven material can be used as an efficient sorbent for removal of investigated basic dyes. Hydrogen peroxide treatment considerably improved the sorption properties of the material for both dyes. The sorption kinetics of dyes on the hydrogen peroxide treated material obeyed pseudo-second order kinetic model. The Freundlich sorption isotherm was found to represent well the experimental sorption data. The increase of initial dye concentration and pH positively affected the sorption of basic dyes. An ion exchange mechanism of dye sorption was confirmed by desorption studies. The toxicity decreased after the sorption of both dyes.