Synthesis, characterization, and antibacterial activity of azodyes incorporated acridine chromophore and their applications in polyester printing

A series of azo dyes incorporated acridine chromophore labelled as 8 (a-d), 10 (a, b), 12 and 14 were prepared in very good yields starting from 9-chloroacridine 1 followed by amination, diazotization and coupling either with rhodanine analogues 6 (a, b) or other coupling partners 9 (a, b), 11 and 13. FT-IR, 1H NMR, and mass spectroscopic analysis were used to establish the structures of the produced azo dispersed dyes. Moreover, the synthesized azo dyes were used to prepare pastes that were used to print polyester fabric using classic silk-screen printing techniques. The dyes were tested for color strength and fastness properties, and they showed good fastness resistance to washing, rubbing, and perspiration, as well as fastness to sublimation and light. The dyes were further screened for their in vitro antibacterial activity against both Gram (+) and Gram (-) bacterial species. Most of them showed promising activities against these tested organisms.

Evaluation of Color Properties of Wool Fabrics Dyed with Calligonum comosum at Different Dye Conditions

In this search, the wool fabric was dyed with a natural dye Calligonum comosum (Callig. Co. dye); the dyeing process was applied under different conditions by changing dye bath temperature, time of dyeing, and pH of dye bath also using different mordants. Ultraviolet protection factor (UPF) was determined for each dyed wool sample. The role of these dying conditions on the via color strength analysis their effects on the reflectance spectra were investigated using the spectro-photometer tool, CIE tristimulus values, and the color parameters. The dye-ability strength and fastness to washing and perspiration properties of these wool samples dyed with (Callig. Co. dye) were carried out spectrophotometrically and evaluated the antimicrobial activity for blank and dyed wool fabrics via gram-positive and gram-negative was followed. The results showed that dyeing wool fabrics with (Callig. Co. dye) increased their protective abilities markedly, and they have effective protection against UV rays, also improving their antimicrobial activity. Moreover, Different conditions of the dye bath changed the optical properties noticeably. The present study will be useful for dermatologists advising patients regarding the UPF properties of clothes made from natural fabrics (wool) and dyed with natural colorants (Callig. Co. dye).

Alternative Thermal Processing Technique for Liquid Foods-membrane Processing

Liquid foods are sensitive to temperature and concentration by conventional methods results in product deterioration. Alternative processes, such as freeze concentration, have the drawback with respect to the maximum achievable concentration (only up to 40 to 45°Brix). In recent years membrane processes such as Microfiltration, Ultrafiltration and reverse osmosis are gaining importance for the concentration of liquid foods. Since heat is not involved in this process, it is also called Alternate thermal processing technique. This process can be employed as a pre-concentration step to reduce water load on subsequent processing steps and can be easily scaled up. Liquid foods such as fruit juices are of high nutritive value as they are naturally enriched with minerals, vitamins and other beneficial components required for human health. When extracted from their sources fruit juices have low solid content, color strength and high-water load. Recent advances and developments in this membrane processing used for the concentration of liquid foods are discussed here.

Rendering viscose fabric dye-able with anionic dyes using plasma treatment technique and chitosan nanoparticles as an eco-friendly approach

Purpose This paper aims at studying the oxygen plasma treatment and the previously prepared and fully characterized chitosan nanoparticles (CNPs) as a green and eco-friendly strategy for surface modification of viscose fabric. This was done to render viscose fabric dye able with two types of acid dyes that do not have direct affinity to fix on it via improving the fabric wettability. Design/methodology/approach To achieve the goal, viscose fabric was activated with oxygen plasma at optimum conditions and coated with different concentrations of CNPs solution via conventional pad dry cure technique. The untreated and plasma-treated fabrics with CNPs were dyed with two types of acid dyes, namely, Acid Orange 7 and Methyl Red under determined conditions. The color strength (K/S), fastness properties to light, rubbing and perspiration, add on %, tensile strength, wettability and durability of the dyed samples were determined and compared. Findings The results divulged that oxygen plasma-treated fabric with CNPs and the aforementioned dyes in question could improve the flowing properties in comparison with untreated fabric: (a) the fabric wettability expressed as wetting area mm2; (b) the dye ability and fastness properties of viscose fabrics expressed as K/S and fastness properties; and (c) the strength properties and add on % of the treated fabric. On the other hand, the durability of the plasma-treated fabric decreased with increasing washing cycles. Originality/value The novelty addressed here was using plasma treatment as an eco-friendly pre-treatment approach for attachment of CNPs as a multifunctional green bio-nano polymer onto viscose fabric, which improved the dyeing properties of the fabric with acid dyes that do not have direct affinity to fix onto it.

Photochemical Stability of a Cotton Fabric Surface Dyed with a Reactive Triphenodioxazine Dye

The paper describes the photochemical stability of a commercial triphenodioxazine dye (Reactive Blue_204) linked onto a cotton fabric. Preliminary studies have shown that as a result of irradiation, the dye and its photodegradation products can pass directly onto the skin under conditions that mimic human perspiration and cause side-effects. The cotton dyed fabric was photo irradiated at different time intervals. Standard methods were employed to evaluate the color strength at various levels of pH, temperature, dyeing contact time, and salt concentration. The influence of UV radiation at different doses (λ > 300 nm) on the structural and color modifications of the dyed cotton fabrics was studied. Structural modifications before and after irradiation were compared by applying FTIR, UV–Vis, and near infrared chemical imaging (NIR–CI) techniques. Color modifications were investigated with the CIELAB system. Color differences significantly increased with the irradiation dose. High irradiation doses caused changes in the dye structure.

Smart Cotton Functionalized With Self-Implanted Palladium Nanopanicles: Full Ultraviolet Shielding Potency

Unique technique is currently demonstrated for preparation of ultraviolet protective cotton fabrics with full shielding effect, via self-implantation of palladium nanopanciles. Palladium (Pd) nanopanciles were in-situ immobilized within native & cationized cotton using two different concentrations of palladium precursor (20 & 60 mM) under strong acidic (pH 2) and basic (pH 11.5) media. Cationization (50% and 100%) of cotton fabrics was performed in order to increase the accessibility of fabric for controllable implantation of palladium nanopanciles. Size distribution of palladium nanopanciles in supernatant solution was estimated via Transmission electron microscopy to be 3.2 nm. The estimated data showed that the sample prepared with the highest cationization percent and highest concentration of palladium precursor in strong alkaline medium exhibited the highest yellowness index, color strength and excellent ultraviolet shielding effects. The yellowness index was significantly increased from 15.67 for cationized cotton to 74.99 for the sample prepared with the highest cationization percent and highest concentration of Pd+2 in alkaline medium (Pd-CC (100)4). Tensile strength was insignificantly decreased from 93.2 MPa for cationized cotton to 84.5 MPa for Pd-CC (100)4. Ultraviolet shielding effect was superiorly enhanced with implantation of palladium nanopanciles. The UV protection factor (UPF) was also excellency increased from 1.3 (insufficient) for native cotton to 256.6 (excellent) for Pd-CC (100)4.

Dyeing of Agro-Waste Castor Fibres with Eclipta Prostrata Dye

Fiber extracted from castor plant is a bast fiber like hemp, jute, flax and kenaf. Based on the chemical constitutes; physical and chemical properties of these eco-friendly fibers extracted from agro waste are used in making different materials like union fabrics and reinforcement materials. In the present study, castor fiber was dyed with Eclipta prostrata plant extract and evaluated for colorfastness and color strength properties. The colorfastness properties of castor fiber dyed with pre, simultaneous and post-mordanting methods using four mordants aluminum potassium sulfate (commonly called alum) (KAI(SO4)2 .12H2O),stannous Chloride (SnCl2), copper sulfate (CuSO4) and ferrous sulfate (FeSO4) were tested. The colorfastness to light, wash, crock and perspiration was found to be good for CuSO4 and FeSO4 dyed fibers. Color strength properties for the samples were also assessed and found to be good.

Extraction of Natural Dye from Aerial Parts of Argy Wormwood Based on Optimized Taguchi Approach and Functional Finishing of Cotton Fabric

The aerial parts of the Argy Worm Wood (AWW) plant have been used in different Chinese foods as a colorant and a taste enhancer for a long time. Despite its application as a food colorant, it has rarely been considered for the coloration of textiles. Keeping in mind the variation in color strength due to the change in phytochemical contents by seasonal change and other variables, the extraction of AWW aerial parts was optimized using the Taguchi method. Optimization was performed on the basis of total phytochemical contents (phenols, flavonoids, and tannins) in the extracted solutions. For this purpose, two different solvent systems, namely sodium hydroxide/water (NaOH/water) and ethanol/water (EtOH/water), were applied through a simple aqueous extraction method at varying levels of solvent concentration, and extraction temperature and duration. Maximum phytochemicals yield of 21.96% was obtained using NaOH/water system with 9 g/L NaOH/water at 85 °C for 20 min and 25.5% with 75% aqueous ethanol at 85 °C for 40 min. Optimized extracts were characterized by UV-Vis and FTIR spectrophotometry, which showed the presence of multiple phytochemicals in the extracts. The dyeing temperature and time were also optimized. Dyed cotton fabrics showed medium to high colorfastness to washing and excellent antibacterial and UV radiation absorption properties. The effect of pre-mordanting with salts of iron and copper was also studied on the color fastness properties. Cotton fabrics dyed with two different solvent system extracts displayed various shades of brown with NaOH/water, and green with aqueous ethanol with and without pre-mordanting. The present study provides the textile industry with a promising source of functional bio-colorant and a value-adding approach for the AWW plant industry.

Mordant-free dyeing of nylon fabric with mahogany (Swietenia mahagoni) seed pods: A cleaner approach of synthetic fabric coloration

The extraction and consequent application of natural colorants obtained from mahogany ( Swietenia mahagoni) seed pod powder is described here. The colored solution was extracted by facile boiling in an acidic medium. Fourier-transform infrared spectroscopy indicated that the mahogany seed pod extract contained lignocellulosic substances. The typical strong broad band for -OH stretching vibration appeared at around the 3400 cm−1 region in the spectra indicating the presence of alcoholic groups in the substance. The acidic boiling of the mahogany seed pod extract showed the color bearing character at λmax 400–480 nm in the visible range of the ultra-violet spectrum. Subsequently, commercial single jersey-knitted nylon fabric was dyed with the mahogany seed pod extract. The effects of temperature, pH, and time were investigated meticulously for the above dyeing. The optimum conditions for nylon fabric dyeing with the mahogany seed pod extract were selected as the temperature of 100°C, dyeing time of 60 min, and dyebath pH 4.5. The results were interpreted in terms of color strength and fastness properties. The color fastness to wash and perspiration of nylon fabric dyed with mahogany seed pod extract was found to be moderate to good in the grey scale rating 3–4 to 4 grade in the case of optimum dyeing condition whereas color fastness to light was observed to be poor in the blue wool scale rating 2 grade. It was observed that dyeing time, temperature, and pH had profound influences on the color strength of the dyed material. The color strength was increased with the increase of dyeing period and dyebath temperature. The acidic dye liquor produced the darker hues while the alkaline condition had no effect on color yielding. The fabric was dyed uniformly, confirming the evenness of dyeing which is very important for successful commercial dyeing.

Investigation onto the Effect of Surface Etching using Chemical Etchants on the Dye-Ability of UHMWPE Fibre

Ultra high molecular weight fibre cannot be dyed using conventional dyeing techniques as they are extremely hydrophobic and do not possess any polar groups. Wet etching of the surface was used as the pre-treatment process to improve the dyeability of the Ultrahigh Molecular Weight Polyethylene (UHMWPE) knitted fabric using potassium dichromate and sulphuric acid as etchants. The surface modified fabric was dyed at 130°C using High Temperature (HT) dyeing technique with disperse dye and evaluated in terms of Color Strength (K/S), washing fastness, rubbing fastness, and tenacity. It has been observed that wet etching improved the colour strength substantially with an overall good fastness to washing and rubbing but the tenacity decreased with an increase in etching time.