THE SYNTHESIS OF COLLOIDAL ZEOLITE HYDROXYSODALITE SOLS BY HOMOGENEOUS NUCLEATION

Colloidal suspensions of discrete particles of microcrystalline hydrox ysodalite have been synthesized from clear homogeneous solutions where in the average particle size determined by dynamic light scattering is 37 nm with a narrow particle-size distribution. Particle-size analysi s performed with various methods yield results that are in agreement. The growth-limiting nutrient has been identified as alumina. As a resu lt, the midsynthesis addition of alumina results in further particle g rowth to 48 nm with the corresponding increase in zeolite yield. Hence , the fine control of particle size and thereby zeolite yield without the formation of a secondary particle population is shown to be possib le. Direct measurements of zeolite yield and particle size allow for a detailed evaluation of the events that occur during crystallization.