Reverse Micellar Dyeing of Cotton Fiber with Reactive Dyes: A Study of the Effect of Water pH and Hardness

Abstract

Effects of hardness and the pH value of water in a water pool on PEG-based nonionic surfactant dyeing of cotton fiber with reactive dyes in a heptane reverse micelle system were investigated in terms of the color yield, reflectance, CIE L * a * b * value, and unlevelness. Results reveal that the effect of the water-pool pH value on the color yield and reflectance are more significant than the effect of hardness in the water pool. The dyed fabrics under an alkaline water-pool condition obtain a lower color yield and higher reflectance percentage than those under acidic and nearly neutral conditions. The increase of hardness in a water pool has higher influence on unlevelness of dyed samples than the increase or decrease of the pH value in a water pool. The changes in hardness and the pH value in a water pool did not result in a significant change in CIE L * a * b * values of dyed specimens, and no chromatic change was found in dyed fabrics. Excellent washing fastness results of the dyed fabrics, guaranteeing adequate removal of unfixed dyes, assure accuracy of the results in a spectrophotometric measurement.

A Comprehensive Review on Liquid-Liquid Extraction Based Systems in Treatment of Textile Wastewater

“…3. Recovery of pollutants from the reverse micellar phase can be easily facilitated by exploiting the de-assembling nature of RMs in aqueous media (61) .…”

Non‐aqueous dyeing of cotton fibre with reactive dyes: A review

“…Further investigations of hydrophilic‐lipophilic balance (HLB) values, reactive dye compatibility matrix, reactive groups of reactive dyes, reactive dye agglomeration, water hardness and pH value in a PEG‐based reverse micellar dyeing system on cotton fibre have also been reported. Experiments on solvent recovery and VOC content detection in a nonane‐based reverse micellar dyeing system have also been conducted.…”

“…Due to growing environmental concerns, several alternative methods for dyeing cotton fibre have been investigated and reported in the literature, including neutral pH dyeing, supercritical carbon dioxide dyeing, reverse micellar dyeing, low‐salt or salt‐free dyeing, clay nanoparticle dyeing, silicone‐based dyeing, two‐solvent miscible dyeing, dyeing with reused wastewater, dye‐solvent suspension dyeing and natural mordant dyeing . The addition of different dyeing methods, modifications of fibre properties (such as cotton cationisation and polymer grafting on cotton), inventions of new reactive dyes with reduced requirements for salt and soda ash, and advancements in effluent treatment technologies, have also been reported.…”

Dyeing of polyamide fabrics with a reverse micellar system using soybean oil as a solvent

“…Thus, in addition to the process reaching a higher colour yield, it effectively reduces the hydrolysis of the dye, chemicals and energy consumption, water treatment and, consequently, the volume of textile effluent. [10][11][12] Recently, Bairabathina and co-workers completed a review of reverse micellar dyeing, 13 describing work carried out in the dyeing of natural fibres with a nonaqueous system by employing ionic, nonionic and mixed surfactants.…”

“…Typically, this type of dyeing process on cellulosic and protein fibres achieves a high rate of adsorption and fixation of the dye without the use of electrolytes and with small amounts of water. Thus, in addition to the process reaching a higher colour yield, it effectively reduces the hydrolysis of the dye, chemicals and energy consumption, water treatment and, consequently, the volume of textile effluent 10–12 …”