K. Sawada and Mitsuo Ueda (2001) studied enzyme processing and dyeing of textile in reverse micellar solution. They examined the bioscouring of cotton with pectinase (pH 4) (Aspergillus niger EC 184.108.40.206) and the modification of wool with protease Bioprase APL-30 (Bacillus subtilis) (pH 7) in the reverse micellar system. At the same time, dyeings of cotton fabrics, polyester fabrics and cotton/polyester fabrics (one-bath dyeing) were carried out with direct dyestuffs, dispers dyestuffs, reactive/dispers dyestuffs, respectively.
It is well known that some kinds of surfactants form reverse micelle in non-polar solvent. The reverse micellar system has excellent properties to solubilize relatively large amounts of water at the interior of reverse micelle and to provide stable aqueous microenvironment, so-called water-pool in the non-aqueous media. Hydrophilic substances such as enzymes and dyes can also be solubilized in the water-pool. If pectinase and other enzymes that are suitably designed for textile processing display their activities in such reverse micellar solution, it can be expected that this enzyme system may have high potential for replacement of conventional practical textile processes.
Surfactant used in this study was sodium bis-2-ethylhexylsulpho-succinate (Aerosol-OT, AOT). In these experiments, the liquors were prepared by an injection of aqueous dye solution and of aqueous stock solution either in buffer alone or enzyme in buffer to 0.05 M AOT/isooctane solutions.
The important parameters were determined, for example weight loss, reduction of wax and residual pectic substance (Methylene Blue Value) for cotton fabrics, tear strength, weight loss, shrinkage percentage for wool fabric with prolonged treatment compared with conventional systems.
As their results, total effectiveness of the bioscouring of cotton with pectinase enzyme could be remarkably improved by the use of the reverse micellar system. Besides total effectiveness of protease for the modification of wool in reverse micellar system is not necessarily excellent compared to those in aqueous system.
As the dyeing results, the construction of continuous one-step process of textile processing and dyeing process is the ultimate subject for the textile industry, reverse micellar system would be one of the most expected candidate system for that purpose.