Cotton is an abundant natural fibre which consists of practically
pure cellulose (about 88e96%) [1]. Cotton may be
described chemically as poly(1,4-b-D-anhydroglucopyranose)
(Fig. 1) [2]. Natural cellulose fibres carry a small negative
charge (zplateau Z 11 mV) due to the presence of some carboxylic
acid groups from oxidation at the primary hydroxylic
sites [3]. At a pH higher than 8, some of the hydroxyl groups
on the hydroxymethyl side chains may also be ionized increasing
the negative charge significantly [4]. The negative charges
on the surface of cellulose repel anionic dyes and hence the
efficiency of dye fixation on cellulosic fibres is generally
low. To counter this problem, a number of studies on cotton
dyeing have been carried out to improve the dye uptake and
fastness properties. Most research focus is on introducingcationic sites into the cotton fabrics for interactions with
anionic dyes