Electrolyte effects in the adsorption and desorption of a cationic polyacrylamide on cellulose fibers

Adsorption isotherms for a cationic derivative polyacrylamide (QCPAM) on cellulose fibers were determined as functions of aluminum sulfate (alum) concentration and pH, and QCPAM desorption measurements in alum, NaCl, CaCl2, and LaCl3 were also made. The isotherms had a steep, but not infinite, initial slope leading to a rounded knee followed by a linear interval with a small positive slope. Polymer adsorption increased with pH due to increased …