Physicochemical Aspects of the Liposome−Wool Interaction in Wool Dyeing

Abstract

Despite the promising application of liposomes in wool dyeing, little is known about the mechanism of liposome interactions with the wool fiber and dyestuffs. The kinetics of wool dyeing by two dyes, Acid Green 27 (hydrophobic) and Acid Green 25 (hydrophilic), were compared in three experimental protocols: (1) without liposomes, (2) in the presence of phosphatidylcholine (PC) liposomes, and (3) with wool previously treated with PC liposomes. Physicochemical interactions of liposomes with wool fibers were studied under experimental dyeing conditions with particular interest in the liposome affinity to the fiber surface and changes in the lipid composition of the wool fibers. The results obtained indicate that the presence of liposomes favors the retention of these two dyes in the dyeing bath, this effect being more pronounced in case of the hydrophobic dye. Furthermore, the liposome treatment is accompanied by substantial absorption of PC by wool fibers with simultaneous partial solubilization of their polar lipids (more evident at higher temperatures). This may result in structural modification of the cell membrane complex of wool fibers, which could account for a high level of the dye exhaustion observed at the end of the liposome dyeing process.

Behaviour of different anaerobic populations on the biodegradation of textile chemicals

“…The higher removal rate of AT could be attributed to its phospholipidic composition, since lipid degradation is favoured with thermophilic bacteria [8]. As both temperatures used in the present study are higher than the transition temperature of liposome lipids (below 0 • C), the continuous fluid state of these lipids maintains the vesicles without structural alterations [4]. However, high temperatures should cause an increase in fluidity, by decrease of molecular order (viscosity decrease).…”

“…Liposomes are vesicular structures with an internal aqueous phase entrapped by a lipid bilayer. They are formed by surface active biological lipids which are the main constituents of cell membranes [4].…”

Thermodynamics of Wool Dyeing

“…Dyes are synthetic aromatic compounds which can bring bright and firm color to other materials. It is reported that over 100,000 commercially available dyes exist and more than 7x10 5 metric tons of dyes are produced worldwide annually [2]. When a textile fiber is immersed in a solution of dye under suitable conditions, the fiber becomes colored, the color of the solution decreases and dyeing has occurred [3].…”

“…Structurally, a wool fiber is an assembly of cuticle and cortical cells held together by the "cell membrane complex" (See Figure 1). The dyeing and diffusion properties of fibers are known as governed by this membranous structure, which is formed predominantly by internal wool lipids [5]. Cross-section diagram of a merino wool fiber [6] Wool cuticle cells (overlapping cells that surround the cortex) are subdivided into two main layers, namely the exocuticle and endocuticle [7].…”

Micro‐Raman spectroscopic study of artificially aged natural and dyed wool

“…Reference literature also supports this theory as traditional methods for dyeing wool use elevated temperatures and products that can damage the fibres and that the dyeing and diffusion properties of the wool and fibres are governed by wool lipids, and thus an understanding of how the dyeing process changes these structures is key to its optimisation. 28 Wool dyed with woad and artificially aged (800 h) has been investigated to determine the level of photodegradation. The resulting micro-Raman spectrum (Fig.…”