Aggregation and sedimentation stability of microcrystalline cellulose suspensions in aqueous aluminum nitrate solutions

The aggregation and sedimentation stability of dilute suspensions of microcrystalline cellulose in aqueous solutions of Al(NO3)3(2 × 10−5–2 × 10−3 mol/l) is studied by the photometric method at pH 2–11. It is found that, in the absence of Al(NO3)3, microcrystalline cellulose suspensions are stable with respect to aggregation throughout the pH range in question. The addition of Al(NO3)3 induces the coagulation and accelerates the sedimentation of microcrystalline cellulose aggregates. At all concentrations of Al(NO3)3, the maximum loss in stability is observed at pH 7–9.