Synthesis, application, and antibacterial activity of new direct dyes based on chromene derivatives

Aim: The goal of this study is to synthesise, analyse, and employ two new direct dyes based on chromenes derivatives as the chromophoric moiety in dyeing wool, silk, and cotton, with good colour strength, light fastness, and other desirable features. Background: The quest for new direct dyes with antimicrobial qualities for Gram-positive, Gram-negative bacteria, and fungus is underway. These dyes are commonly used on cotton, silk, and wool materials, which have great light fastness, washing, rubbing, and sweating fastness. Methods: Antibacterial activity has been measured for all dyeing fabrics. The parent structure 1 has been synthesized previously as part of the experiment. Then, these dyes are prepared by diazotization followed by coupling reaction, Results and Discussion: The p-Aminobenzenesulfonic acid (C1) and 4-Aminoazobenzene-3,4'-disulfonic acid (C2) are diazotized in hydrochloric acid with sodium nitrite, then coupled with compound 1 in a molar ratio (1: 1) at 250C until the pH is fixed at 5. Finally, the monoazo and diazo direct dyes (D1 and D2) are created. Conclusion: Wool, silk, and cotton materials benefit from the synthetic dyes' increased antibacterial action and dyeing qualities (exhaustion and fixing). They also offer better fastness qualities (light, rubbing, and perspiration).

Graphene Oxide Embedded Copper Composite as an Efficient Mordant to Enhance the Properties of Natural Dye Coated Cotton Fabric.

In the textile sector, the utilization of synthetic dyes is environmentally unfriendly and has a very harmful impact on human health and the environment. Hence, natural dye is assumed to be a suitable alternative for sustainable textile manufacturing and colouration, but it remains challenging to prepare the dyes having high stability with textile fablric. Herein we have demonstrated the dyeing process for cotton fabric with natural dye extractions from turmeric (Curcuma longa L.) and tea (Camellia sinensis) in the presence of mordant. Subsequently, we have prepared copper and 2-methyl 8-hydroxyquinoline functionalized graphene oxide (GO) (CHG) trinary-composite as mordant to improve the stability and colour strength of naturally extracted dyes. The prepared trinary-composite was investigated using various techniques such as FTIR, XRD, UV, and TGA analysis. To evaluate the effect of CHG composite, it mixed with natural extracted dyes such as turmeric and tea dyes, converted to CHG functionalized turmeric and tea dyes (TuCHG and TeCHG) for the dyeing of cotton fabric. TuCHG and TeCHG dyed cotton fabrics exhibited superior colourfastness, wash fastness and rub fastness in comparison to only turmeric and tea dyes dyed cotton fabrics. TuCHG and TeCHG dyes also demonstrated decent antibacterial properties. The present study indicates the new aspect for prepared mordant to increase natural dye colour strength and stability. Thus, this process is a much safer, cost-effective and sustainable method for the application of natural dyes with enhanced substantively for cotton fabric.

Study on Exhaustion Behaviour of Red Chili on Cotton Fabric

Dying is a popular practice in textile industry which is prevalent at all parts of the world from the period of ancient civilization. Initially, natural dyes i.e. dye derived from natural resources like vegetables, flowers, minerals, plants etc. were used. Now-a-days, due to technological and scientific innovations synthetic dyes are processed at large scale in the laboratories as it is still one of the most profitable industry globally. However, the rapid utilization of chemicals in textile industry for production of synthetic dyes causes degradation of environment like soil pollution, water pollution etc. Hence, it is necessary to promote the utilization of natural dyes globally. In this paper, the exhaustion of dye extracted from red chillies, one of the most used vegetables same has been studied on cotton fabrics at different temperatures using UV-Visible light spectrophotometer. The colour strength of the fabric before and after application of soap therein are also studied experimentally. Keywords: Natural dye, red chillies, cotton fabrics, exhaustion of dye, absorption.

Analysis of Enervation Conduct of Indian Maddar Natural Dye on Silk Fabric

Dying is a popular practice in textile industry which is prevalent at all parts of the world from the period of ancient civilization. Initially, natural dyes i.e. dye derived from natural resources like vegetables, flowers, minerals, plants etc. were used. Now-a-days, due to technological and scientific innovations synthetic dyes are processed at large scale in the laboratories as it is still one of the most profitable industry globally. However, the rapid utilization of chemicals in textile industry for production of synthetic dyes causes degradation of environment like soil pollution, water pollution etc. Hence, it is necessary to promote the utilization of natural dyes globally. In this paper, the bleached silk fabric was dyed with Indian Madder natural dye at different temperature and the colour strength is measured spectrophotometrically in order to study the effectiveness of the dye. Keywords: Natural dye, bleached silk fabric, Indian Madder, Colour strength

THE EFFECT OF PLASMA TREATMENT ON THE PRINTABILITY OF POLYESTER FABRIC USING COCHINEAL NATURAL DYE

Use of synthetic dyes for dyeing of textile fabrics is most problematic environmental concerned for textile industry. The demand of natural colourants for the dyeing of textile fabrics has been increasing. Thus, sustainable novel technologies for textile dyeing are needed that utilize improved colour strength and enhanced performance characteristics of the fabric. This study attempts to highlight the possibility of using cochineal natural dye in the printing of polyester fabrics after surface modification by O2/Ar plasma treatment. The colour strength, air permeability, crease recovery angle of printed fabrics, colour fastness to rubbing, washing and light, were also studied. The surfaces of untreated and plasma-treated polyester fabrics were analysed by SEM to compare the morphological changes. Surface roughness and cracks were indicated after the plasma pretreatment. The results indicated that plasma treatment could improve the printability of polyester fabric compared with untreated samples, with enhanced the adhesion and penetration of printing paste to the surface. The air permeability of printed fabrics has decreased, while the angle of crease recovery has increased. The fastness properties of printed samples were found suitable to very good.

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.

SURFACE CHEMICAL ANALYSIS OF C.I. LEUCO SULPHUR BLACK 1 DYED COTTON FABRIC AFTER-TREATED WITH PLANT-DERIVED TANNIN-BASED PROTECTIVE AGENT

In this investigation, the X-ray photoelectron spectroscopic technique has been used to examine the surface chemistry of C.I. Leuco Sulphur Black 1 dyed cotton fabric, which has been after-treated with a tannin-based commercial product, Bayprotect CL, and laundered in accordance with ISO 105 C06 and C09 washing protocols. The dyeings were evaluated for colour strength, wash fastness and colour loss. Surface chemical compositions of the dyeings were analysed to relate visual changes with surface chemical changes. Alterations in percentage atomic concentrations of carbon, nitrogen, oxygen and sulphur were compared for untreated, after-treated, unlaundered and laundered dyed samples. After-treated and laundered dyed samples exhibited higher content of surface sulphur and lower surface oxidation, as compared to the untreated counterparts. The S (2p) spectra of after-treated and laundered samples demonstrated reduced over-oxidised (S6+) species at 168 eV. There was 5% and 4% less surface oxidation for ISO 105 C06 and C09 washing systems, respectively.

Sustainable Dyeing of Cellulosic Fabric with Reactive Violet H3R dye: Ultrasonic Assisted Improvement in Color Characteristic

Ultrasonic radiation (U. S.) is the sustainable and green technology which has transformed the domain of textiles. In the current study, ultrasonic treatment was employed to improve the reactive dyeing of cellulosic fabricby Violet H3R dye. For this purpose, U.S. treatment has been given to both solution & fabric upto 50 min. at 30 to 60 oC. Promising results were obtained when cellulosic fabric was exposed to U.S. treatment at at 50 oC for a period of 30 min. using dye bath of 55 mL having 7.5 pH. Glauber salt (8 g/L) was employed as an exhausting agent at 60 oC for 55 min. Various shades of cotton fabric dyed at optimal conditions were obtained which showed that U.S. treatment has enhanced not only the colour strength but also the fastness rating from medium to outstanding. So, it can be concluded from the current study that U. S. treatment is not only good enough for improving the dyeing aptitude of Reactive Violet H3R dye but it also uplifts the color features of dyed cotton fabric. Resumen. La radiación ultrasónica (U:S. por sus siglas en inglés) es la tecnología sostenible y verde que ha transformado el campo de los textiles. En este estudio, se llevó a cabo un tratamiento ultrasónico para mejorar el teñido reactivo de tela celulósica por el tinte Violet H3R. Para este propósito, se llevó a cabo un tratamiento con ultrasonido tanto a la solución como a la tela por hasta 60 minutos a 30 y 60 oC. Se obtuvieron resultados prometedores cuando la tela celulósica se expuso a un tratamiento con ultrasonido a 50 oC durante un período de 30 min, utilizando un baño de tinte (de 55 mL) a pH 7,5 de sal de Glauber (8 g/L). Estas condiciones representan un sistema de agotamiento, aplicado a 60 oC durante 55 min. Se obtuvieron varios tonos de tela de algodón teñidos en condiciones óptimas, lo que mostró que el tratamiento por ultrasonido mejora no solo la intensidad del color sino también el índice de solidez de media a sobresaliente. Por lo tanto, del estudio actual se puede concluir que el tratamiento con ultrasonido no solo es lo suficientemente bueno para mejorar la capacidad de teñido del tinte Reactive Violet H3R, sino que también realza las características del color de la tela de algodón teñida.

Digital Sublimation Printing on Knitted Polyamide 6.6 Fabric Treated with Non-Thermal Plasma

The garment industry demands stamping processes that are increasingly more agile and less damaging to the environment. In this scenario, digital printing, with the sublimation transfer printing technique, presents itself as a viable option for synthetic textile substrates. Among the synthetic fibres, polyamide (P.A.) fibres stand out, as they are light, soft, durable, and boast moderate sweat absorption; however, before sublimation, superficial treatment is necessary in order to present good results such as withstanding washing and maintaining colour intensity. This study addresses the surface modification of the PA6.6 textile substrate by activating non-thermal plasma at atmospheric pressure to receive dye through the sublimation method with dispersed dye. The knitted PA6.6 fabric surface treatment was performed with plasma application at atmospheric pressure using air in the Plasmatreater AS400 equipment. The sublimation transfer effects were evaluated by wash fastness and colourimetric tests. To assess the wettability effect of the control and treated samples, a contact angle test was carried out on PA6.6 samples. Fourier transform infrared spectroscopy (FTIR) proved the changes in chemical functional groups in the fibres. The results showed a decrease in the contact angle of the textile surface, 4–5 grayscale results for colour change and transfer for washing, and an increase in colour strength. In the FTIR tests, there is an increase in the transmittance value of aromatic, carboxylic groups (C=O, 580 cm−1), amides (N=H, 1630 cm−1), and methyl groups (CH 1369 to 1463 cm−1) as well as the presence of new functional groups in the 3064 cm−1 and 2860 cm−1 bands. These conditions allowed sublimation in the knitted PA6.6 fabric and showed increased colour strength and good wash fastness.

Ultrasonic dyeing of wool fabric with aqueous extract of Ratanjot (Onosma echioides) natural dye

The purpose of this study is to compare the conventional and ultrasonic dyeing methods in terms of its colour strength and colour fastness properties of wool fabric dyed with Ratanjot root. The results suggested that dyeing of wool fabric with natural dye Ratanjot (Onosma echioides) using ultrasonic waves, significantly improved the dye uptake percentage to 12.31 per cent from conventional heating methods. The fastness grade were found to be higher with ultrasonic than conventional heating. Additionally, the fabric dyed using ultrasonic waves gave a deeper shade and good colour intensity even at lower dyeing time (75min) and temperature (60°C). Therefore, ultrasound wave represents a promising technique for increasing diffusion of dye by the effect of cavitation, as well as for improving the effectiveness of processes when compared to conventional heating