Mercerisation changes the fine structure, morphology and conformation of co
tton cellulose chains (cellulose I to cellulose II), resulting in a variati
on in fibre strength and lustre as well as adsorption properties. Recently
it has been shown that mercerisation also changes the electrokinetic behavi
our of cotton. The aim of the work presented here is to study the behaviour
in unmercerised and mercerised cotton. The zeta potential of cotton fibres
was measured by the streaming current method, using an EKA electrokinetic
analyser. The relationships between zeta potential and the pH of a potassiu
m chloride solution on the one hand and the point of zero charge (PZC) on t
he other, determined by titration with a cationic surfactant (cetylpyridini
um chloride), were investigated.