α-Fe_2O_3单分散溶胶在EDTA溶液中的稳定性

Stability of Monodispersed Hematite Sols in the Presence of the EDTA Solution

EDTA的浓度和介质PH的变化可以引起a-Fe_2O_3单分散溶胶的絮凝和再稳定。再稳定是由于带有正电荷的胶体粒子吸附了过剩的负离子,导致粒子表面电性反号引起的。C.C.C和C.S.C强烈依赖于介质的PH。该絮凝机理属于吸附凝机理,受表面化学反应所控制。

Coagulation and stabilization of monodispersed hematite sols may be caused by con- centration of the EDTA and change of the PH of the medium.The restabilization is caused by reversal of charge due to adsorption of the excess negatively ions on positively charged sols.Critital coagulation concentration(C.C.C)and critital stabilization concentration (C.S.C)intensely depend on the PH of the medium.Coagulation mechanism belongs in adsorption coagulation mechanism which is controlled by surface chemical reaction.