Evaluation of dyeing properties of natural dyes extracted from the heartwood of Prosopis juliflora on cotton fabric

Purpose Considered as one of the most unwanted species by the International Union for Conservation of Nature, the Prosopis juliflora plant is a noxious and invasive weed. Recent studies suggest that the heartwood of the plant has an unusually high amounts of flavonoids with potential medicinal properties and dyeing potentials. In this work, acetonic extracts were successfully valorized into a natural dye. Design/methodology/approach After extraction and optimization of dyeing conditions, the fabric was treated by using pre-mordanting, simultaneously mordanting and post mordanting techniques. The dyed samples were then evaluated by using standard methods ISO 105-C06, ISO 105-A02, ISO 105-X12 for wash, light and rub fastness, respectively. Findings Dye fastness ranged from good to very good with mordants improving both wash and rub fastness. Optimum pH for dyeing was found to be at 7.2 at temperatures of 60°C and a dyeing time of 80 min. Application of mordant in dyeing white fabric showed improved dyeing properties in post mordanting than both pre-mordanting and simultaneous mordanting. Originality/value To best of the authors’ knowledge, this paper details for the first time how a noxious weed can be transformed into a natural dye, with potential applications to the textile industry.

Sonochemical co-deposition of antibacterial nanoparticles and dyes on textiles

The sonochemical technique has already been proven as one of the best coating methods for stable functionalization of substrates over a wide range of applications. Here, we report for the first time on the simultaneous sonochemical dyeing and coating of textiles with antibacterial metal oxide (MO) nanoparticles. In this one-step process the antibacterial nanoparticles are synthesized in situ and deposited together with dye nanoparticles on the fabric surface. It was shown that the antibacterial behavior of the metal oxides was not influenced by the presence of the dyes. Higher K/S values were achieved by sonochemical deposition of the dyes in comparison to a dip-coating (exhaustion) process. The stability of the antibacterial properties and the dye fastness was studied for 72 h in saline solution aiming at medical applications.

Effect Of Dyeing On Wrinkle Properties Of Cotton Cross-Linked By Butane Tetracarboxylic Acid (BTCA) In Presence Of Titanium Dioxide (TiO2) Nanoparticles

This study evaluates the wrinkle behaviour and wrinkle resistant properties of cotton fabrics dyed by Direct Blue 2B in the presence and absence of nano-TiO2 particles. A finishing process on samples was performed before dyeing by means of 1,2,3,4-butanetetracarboxylic acid (BTCA) and sodium hypophosphite (SHP) using a pad dry cure method. Such experiments as wrinkle recovery test (AATCC-128), water drop test and dye fastness determination (ISO 105-C01) were conducted to understand how current treatment impacted the cotton fabrics’ properties. Finally, samples were characterised using the X-ray diffractometery method to scrutinise how crystallinity changes and dominates the structural parameter (wrinkle behaviour) of cotton fabrics. Furthermore, scanning electron microscopy (SEM) was used to visualise the surface variations of the samples before and after dyeing process. The results showed that the wrinkle resistant of cross-linked fabrics have been improved after direct dyeing. Furthermore, levelness dyeing and good fastness properties of dyes on cross-linked fabrics were observed.

The Dyeing Properties of Esterified Wools

The effect of esterification of wool on its behavior toward acid dyes has been studied. Esterified wool shows an increase in dye affinity, and dyed esterified wool shows an increase in dye fastness to washing in soap and soap-soda. The process of esterification with methanol/hydrogen chloride is not entirely specific and also causes some modification of amide and other groups.