2.3.3. Polyelectrolyte titration method
Polyelectrolyte titration was carried out using polyelectrolyte
titration system, particle charge detector (PCD 03 PH), was from Mütek Analytic GmbH, Herrsching, Germany. One gram climatized
treated cotton were immersed in 100 ml acetate buffer solution
(pH 4.7). To this solution 100 ll Marlipal was added. The cotton
samples were left under shaking for 2–3 h. Then the cotton samples
were washed several times with distilled water and dried at ambient
conditions. 50 ml anionic polyelectrolyte (0.001 N polyethlenesulfonic
acid sodium salt; PES-Na) (Fig. 2) and 100 ll Marlipal were
added with stirring for 3 h to the cotton fabrics. After stirring, the
solutions with the cotton fabrics were filtered out. 10 ml from
the filtrate was titrated against cationic polyelectrolyte; poly-diallyl-
di-methyl-ammonium-chloride (PDADMAC 0.001 N) (Fig. 2).
The volume consumed during the titration was called (V1). For calibration,
10 ml (PESNa) was titrated against (PDADMAC), the volume
determined was called (V2). The amount of titer
consumption at the end point of titration can be used for the calculation
of accessible charges according to the following equation:
MilliVolt:equivalent ðmV:eq:Þ ¼ ½ðV2 V1Þ 0:001=0:2: