Mechanism involved in the dyeing of wool with an oil‐in‐water microemulsion system

Abstract

This article investigates the influence of oilin-water (o/w) microemulsions, used as media for both dye solubilization and dye baths, on the dye uptake on fiber surfaces. An acetic acid solution/Synperonic L7/benzyl alcohol microemulsion system was used to solubilize a water-insoluble antimicrobial natural dye (C.I. Natural Orange 2) and to dye wool fabric at an acidic pH. The results clearly show that the dye exhaustion on the fabric took place mainly when the temperature of the dye bath promoted a change in the molecular organization of the microemulsions with the liberation of the dye solubilized in the oil droplets of the microemulsions. Although uniformly and evenly dyed fabrics were obtained, they showed very low wash fastness. To confirm the mechanism involved and to achieve dyed fabrics with good wash-fastness properties, two different dyeing methods were also studied. The first method was dyeing at a constant low temperature, at which the o/w microemulsion remained a monophase system; the second one was dyeing at a high temperature, at which it was transformed into a multiphase system. Both the dye exhaustion and wash fastness improved considerably for the fabrics dyed at a high temperature. Moreover, uniform and even dyeing was achieved.

Synthesis and application of nonionic Gemini surfactants based on grape seed oil

“…When nylon is dyed with acid dyes, the hydrogen ions provided by the acid dyebath generate positive charges on the amino group of the fibre, which can easily absorb the negative charge of the acid dye. 27,28 The process of forming ionic bonds is very rapid. In addition, there are hydrogen bonds and van der Waals forces between the dye and the fibre.…”

Synthesis of acid dyes containing polyetheramine moieties and their low‐temperature dyeing properties on wool fiber

“…On the other hand, to achieve the low‐temperature dyeing of wool, many endeavors have been made, such as liquid‐ammonia pretreatment, enzyme pretreatment, corona treatment, UV radiation, alkaline agent treatment, low‐temperature plasma pretreatment, the use of a microemulsion system, and microencapsulation . However, these dyeing methods at low‐temperature have not yet been used practically.…”

Solubilisation study of water‐insoluble dye in cationic single/dimeric surfactant micelles: effect of headgroup, non‐polar tail, and spacer chain in aqueous and salt solution

“…This has been reported to be greatly influenced by external factors such as temperature, pressure, pH, and ionic strength [1][2][3][4][5][6][7][8][9][10][11][12][13]. Surfactant-dye interactions are important to understanding dye solubilisation in surfactant micelles and the dyeing mechanism, including the kinetics and thermodynamics of the dyeing process.…”

“…Hence, the solubilising power of the surfactant is expressed as the number of moles of solubilised substances per mole of micellar surfactant and depends not only on the nature of the micelles but also on the structure of the solubilised dye molecules. This has been reported to be greatly influenced by external factors such as temperature, pressure, pH, and ionic strength .…”