METHOD FOR PREVENTING AGGLORMERATION OF CHARGED COLLOIDS WITHOUT LOSS OF SURFACE ACTIVITY

摘要

A method for chemically stabilizing polishing slurries in aqueous suspension to prevent their agglomeration while maintaining their surface activity is disclosed. The method prevents the formation of irreversible particle agglomerates during drying and permits the subsequent re-suspension of dried particles with no impact on the particle size distribution. The stabilization method can be customized based on knowledge of the colloid surface charge at suspension pH conditions, addition of a charged species having like charge to the colloid at the suspension conditions, and control of the concentrations of the charged species and other ions in suspension.

主权项

1. A suspension comprising:
a solvent; a plurality of solid particles supported in the solvent, wherein each of the plurality of solid particles has a first charge layer having a first polarity and disposed over an outer surface of the solid particle and a second charge layer overlying the first charge layer and having a second polarity different from the first polarity; and a plurality of charged species, wherein at least some of the plurality of the charged species are attached to the second charge layer and wherein the charged species have a charge polarity that is same as the first polarity.