Jakub Wiener

UV protection properties of silk fabric dyed with eucalyptus leaf extract

A natural dye extracted from eucalyptus leaves was applied to a silk fabric using two padding techniques, namely the pad‐batch and pad‐dry techniques, under different conditions. It was observed that with an increase in the dye concentration, the ultraviolet (UV) protection factor (UPF) values ranged between good and excellent for the silk fabric. In addition, a darker colour, such as that provided by a FeSO4 mordant, gave better protection because of higher UV absorption. A silk fabric dyed in a solution containing the eucalyptus leaf extract showed a shade of pale yellowish‐brown. The exception was when the fabric was dyed with the FeSO4 mordant, resulting in a shade of dark greyish‐brown. The colour fastness to washing and rubbing of the silk fabrics treated with the mordant after dyeing was investigated and the results showed good fastness, whereas colour fastness to light was at a fair level. The results confirmed that natural dyes from eucalyptus leaf extract with metal mordants have potential applications in fabric dyeing and in producing UV‐protective silk fabrics.

Coating of cellulose-TiO2 nanoparticles on cotton fabric for durable photocatalytic self-cleaning and stiffness.

A new route to make cotton fabric self-cleaning and permanently stiff by coating cellulose-TiO2 on its surface is demonstrated herein. Cellulose-TiO2 dispersion was used for coating and was prepared by mixing TiO2 nanoparticles with cellulose in 60% H2SO4 solution. The surface morphology of cellulose-TiO2 nanoparticles coated sample was analyzed by SEM. The appearance of white TiO2 particles on the surface of the cotton fabric confirmed the successful coating process. The Orange II dye was used as stain and its degradation was observed under UV light. X-ray diffraction analysis showed that cellulose II content increases slightly (by 5.3%) after the solvent treatment. Washing fastness study showed that the fabric stiffness was permanent and self-cleaning properties were stable with 1, 3 and 5% TiO2 coated samples. Air and water vapor permeability was not decreased considerably, whereas tensile strength was increased significantly after coating.

Antibacterial Agents in Textile Industry

The spread of HIV and hepatitis viruses by contact of contaminated materials has created increased pressure for protection of personnel with functional clothing; also, all articles of apparel and home textiles are susceptible to problems of hygiene in normal daily use, for example, socks, sport wear and working clothes as well as mattresses, floor coverings, and shoe linings. Textiles for outdoor use are constantly exposed to the influence of microbes and bacteria. Application of natural antimicrobial agents on textiles dates back to antiquity, when the ancient Egyptians used spices and herbs to preserve mummy warps. Textile goods, especially those made from natural fibers, provide an excellent environment for microorganisms to grow, because of their large surface area and ability to retain moisture. Most textile materials currently used in hospitals and hotels are conductive to cross infection or transmission of diseases caused by microorganisms. Practically every class of chemical compound has been utilized to impart antibacterial activity to textiles. Two different aspects of antimicrobial protection provided by chemical finishes can be distinguished. The first is the protection of the textile user against pathogenic or odour causing microorganisms (hygiene finishes). The second aspect is the protection of the textile itself from damage caused by mould, mildew or rot producing microorganisms. Bacteria are not as damaging to fibres, but can produce some fibre damage, unpleasant odours and a slick, slimy feel. Often, fungi and bacteria are both present on the fabric in a symbiotic relationship. (Heywood, 2003; Bellini, 2001)

Dyeing of wool and silk by eucalyptus leaves extract.

Wool and silk fabrics were dyed using the water extract obtained from eucalyptus leaves; essentially higher utilization of dyestuffs and shortening of the dyeing procedure was achieved as a result of the padding dyeing principle followed prior to drying. Simultaneous mordanting by FeSO4 shows brown-grey color of different shades depending on the dye concentration. The dye exploitation of wool is higher than that of silk, and in both cases common “exhaustion” methods are better than “long baths.” The ecological and economical considerations of dyeing by natural dyestuffs are discussed.

Novel techniques to analyse thermal performance of aerogel-treated blankets under extreme temperatures

The thermal properties of polyester/polyethylene non-woven blankets of varying thicknesses impregnated with aerogel were studied and compared. The SEM images were also taken to study the physical configuration of the aerogel-based fibrous webs. Specific thermal properties like conductivity, resistance and effusivity were measured using C-Therm TCi thermal conductivity analyzer. One major objective was to understand the potential of a newly fabricated equipment to study the thermal properties of non-woven textile fabrics treated with aerogel at sub-zero temperatures. Thermal conductivity was calculated using the empirical relation in Fourier’s law. The relationship between the thermal conductivity and thermal resistance of the samples was studied at various environmental temperatures (which was set in the climatic temperature system between (+25°C and −25°C). The newly fabricated equipment was found to be suitable for thermal measurements at sub-zero temperatures. The results were statistically analysed and compared. It was found that fabric thickness and density have a significant effect on the thermal properties and permeability of the aerogel-treated non-woven fabrics. The results also showed that the selected polyester and polyethylene non-woven fabrics were suitable for usage as thermal insulators during construction of buildings and for insulation of oil and gas pipelines.

Effect of electron irradiation on dye and printability of polypropylene (PP) fabrics: a novel method for decoration of PP fabrics

Polypropylene (PP) has a very low value of the surface free energy (approximately 20–25 mJ m−2). And thus, has very weak hydrophilic properties and doesn’t have any affinity to any dyestuffs, such as cationic or anionic dyes. In this study, we covered some parts of PP fabrics by mask, and then irradiated them by electrons with different energies. After electron irradiation, the samples were dyed by cationic dyestuff. The result showed that, electron irradiated parts could be dyed easily and the fabric could be printed and decorated simply. The treated surfaces were investigated by scanning electron microscope (SEM), reflective spectrophotometery, and Fourier transform infrared spectroscopy (FTIR). Also, light and wash fastnesses of printed samples were measured. The results are reported.

Effect of Plasma on the Zeta Potential of Cotton Fabrics

In this work, the effect of a low-temperature plasma on the zeta potential of cotton fabric was studied. The silver particle absorption on cotton fabric when modified by a low-temperature plasma was also investigated. The modification consisted of plasma pre-functionalization followed by a one-step wet treatment with silver nitrate solution. The process was performed in a low-temperature plasma medium, using a magnetron sputtering device. Oxygen and nitrogen were used as working gases in the system, and the results were compared. After preparing the samples, the zeta potentials of the untreated and plasma-treated cotton under a constant pH value solution were estimated and compared. Also, Fourier transform infrared spectroscopy (FTIR) was used to examine the functional groups of the corresponding samples. The amounts of silver absorption on plasma treated and untreated cotton were examined using the energy dispersive X-ray (EDX) method. The results show that the amount of zeta potential for the nitrogen plasma treated sample is less and the absorption of silver particles by cotton can be increased strongly with nitrogen plasma treatment.

Natural Dye from Eucalyptus Leaves and Application for Wool Fabric Dyeing by Using Padding Techniques

Natural dyes are known for their use in colouring of food substrate, leather, wood as well as natural fibers like wool, silk, cotton and flax as major areas of application since ancient times. Natural dyes have a wide range of shades that can be obtained from various parts of plants, including roots, bark, leaves, flowers and fruits (Allen, 1971). Since the advent of widely available and cheaper synthetic dyes in 1856 having moderate to excellent colour fastness properties, the use of natural dyes having poor to moderate wash and light fastness has declined to a great extent. However, recently there has been revival of the growing interest on the application of natural dyes on natural fibers due to worldwide environmental consciousness (Samanta & Agarwal, 2009). Although this ancient art of dyeing with natural dyeing with natural dyes withstood the ravages of time, a rapid decline in natural dyeing continued due to the wide available of synthetic dyes at an economical price. However, even after a century, the use of natural dyes never erodes completely and they are still being used. Thus, natural dyeing of different textiles and leathers has been continued mainly in the decentralized sector for specialty products along with the use of synthetic dyes in the large scale sector for general textiles owing to the specific advantages and limitations of both natural dyes and synthetic dyes. The use of non-toxic and ecofriendly natural dyes on textiles has become a matter of significant importance because of the increased environmental awareness in order to avoid some hazardous synthetic dyes. However, worldwide the use of natural dyes for the colouration of textiles has mainly been confined to craftsman, small scale dyers and printers as well as small scale exporters and producers dealing with high valued ecofriendly textile production and sales (Samanta & Agarwal, 2009; Bechtold & Mussak, 2009; Vankar, 2007). Recently, a number of commercial dyers and small textile export houses have started looking at the possibilities of using natural dyes for regular basis dyeing and printing of textiles to overcome environmental pollution caused by

LIBS analysis of chromium in samples of dyed wool fabric

A method for the analysis of chromium in wool fabric samples was developed. It is fast and cheap with no sample preparation. This method involved the use of double pulse Laser Induced Breakdown Spectrometry (LIBS) for the wool fabric samples dyed by two types of metal complex dyes (C.I. Acid Orange 173 and C.I. Acid Black 60). A commercially available LIBS spectrometer was calibrated with the aid of authentic wool fabric samples previously analysed by F-AAS after microwave digestion. Comparable results can be obtained using this unique procedure if the same set of standards is used for XRF and LIBS calibration. Limits of detection for chromium achieved by suggested LIBS methods (from 5 to 10 mg kg−1) are comparable with the WD XRF ones (from 4 to 5 mg kg−1).

Static and dynamic mechanical properties of novel treated jute/green epoxy composites

The focus of this paper is to evaluate the mechanical and dynamic mechanical properties of woven jute fabric-reinforced green epoxy composites as a function of modification of jute fibers by enzyme, CO2 pulsed infrared laser and ozone treatments. The treated jute fibers were characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. Composites were prepared by the hand layup method and compression molding technique and the resin curing process was optimized with the help of differential scanning calorimetry. The treatments resulted in the enhancement of flexural and impact properties. Statistical analysis of mechanical properties of composites, done by one-way analysis of variance, showed significant differences between the results obtained. Dynamic mechanical analysis (DMA) results revealed that treated composites have a higher storage modulus over the range of temperature. A positive shift of loss modulus and tangent delta peaks of treated composites to higher temperature was observed. The reduction in the tangent delta peak height of treated composites was also observed due to improvement in fiber/matrix interfacial adhesion. The degree of interfacial adhesion between the jute fiber and green epoxy was anticipated using the adhesion factor obtained through DMA data. Complex modulus variations and phase behavior of composites was studied by Cole–Cole analysis.