The effect of polyampholytes (PAmp) is explained by their high affinity with cellulose fibers and their adsorbed conformation. Due to their unique charge characteristics and the possibility to fine tune their colloidal behavior, polyampholytes are been used in a number of novel applications, under a wide variety of conditions.
However, polyampholyte adsorption can be significantly affected by other chemical additives typically present in the papermaking furnish. Therefore, the optimum condition of use is not only determined by PAmp solution properties but also by the dissolved and colloidal substances present, pH, ionic strength, etc.
In this study, we evaluated the effect of polyaluminum chloride (PAC), which is a representative cationic additive, on the adsorption of polyampholytes on cellulose surfaces. The adsorption behaviors were investigated by using elemental nitrogen analysis on cellulose fibers and the QCM-D technique (using thin films of cellulose). The colloidal behaviors were analyzed for polyampholytes with same molecular mass but different cationic:anionic ratios. In this report we discuss the effect of PAmp charge density and PAC concentration on the extent of adsorption, energy dissipation, fiber strength and fiber network formation.