Electrokinetic Measure
An electrical voltage is generated when a liquid moves under pressure through a fixed porous material like a textile fabric. Measuring streaming potential allows researchers to evaluate the surface charge of fibres during chemical processing. This data indicates how well additives like softeners or dyes will attract to the substrate.
Surface Analysis
Evaluation of this property involves pumping an electrolyte through a sample of yarn and measuring the resulting millivolts. When a streaming potential is negative, it shows the fibre holds a net negative charge, which is typical for untreated cotton. Shifts in this value signal the successful application of finishings that alter the fabric feel.
Interaction Force
Electrostatic attraction between the dye molecules and the fibre wall governs the rate of uptake. Using streaming potential as a guide, mills can adjust the chemical balance of the water to increase or decrease the efficiency of the bond. These small adjustments prevent the waste of expensive reagents and improve the uniformity of the color across whole rolls of fabric.
Limit Of Measurement
Signal accuracy decreases if the liquid is too high in salt content. Because high conductivity short-circuits the measured voltage, streaming potential is best analyzed in relatively clean water. Most laboratories use specific standard liquids to maintain consistency when comparing results from different production days.
