Stability of nanocrystalline cellulose in aqueous KCl solutions

Resumo

The electrokinetic properties and aggregation stability of nanocrystalline cellulose sols in aqueous KCl solutions have been studied at pH 5.2. Cellulose nanoparticles have been prepared via controlled degradation in a mixture of phosphotungstic and acetic acids. At electrolyte concentrations of <0.01 mol/dm³, the system is stable to aggregation. The experimentally determined threshold of fast coagulation is 0.08 mol/dm³. It has been noted that the structural component of disjoining pressure must be taken into account when considering the aggregation stability of nanocrystalline cellulose sols in terms of the DLVO theory. It has been shown that the sizes of water boundary layers decrease with an increase in the KCl concentration. The effect of medium pH on the electrokinetic potentials and sizes of aggregates has been studied.