Use of the Streaming Current Detector to Measure Wet-End Charge: Some Mechanistic Insights, 1998 Coating Conference Proceedings
Measurement of cationic demand by polyelectrolyte titration using the streaming current detector (SCD) is becoming increasingly common in paper mills as a method for controlling dosage levels of wet-end chemicals. Results from these measurements generally have to be treated empirically and do not correlate well with other methods of charge determination. This paper describes laboratory experiments with the SCD and illustrates some of the reasons for the difficulties experienced when interpreting results. The importance of the kinetics of polymer adsorption and non-charge-stoichiometric interactions are demonstrated. Data using the SCD in combination with a Britt jar show the differences in adsorption stoichiometry and flocculation mechanism of three commonly-used polymers. The interpretation of measurements of cationic demand is discussed in the light of these experiments.
Use of the Streaming Current Detector to Measure Wet-End Charge: Some Mechanistic Insights, 1998 Co