Synthesis of uniform, spherical sub-100 nm silica particles using a conceptual modification of the classic LaMer model

A strategy for production of monodisperse spherical sub-100 nm silica particles is demonstrated based on application of a conceptual modification of the classic LaMer model to the Stöber process. Strategies for control of particle properties, including particle size, size distribution, and shape are proposed. The approach demonstrated herein starts from a small number of test experiments and then focuses on adjusting the reaction conditions that control undesirable particle properties of the resulting particles while leaving conditions that dictate desirable properties unchanged. This strategy reduces considerably the number of test experiments required for synthesis of uniform and spherical sub-100 nm silica particles compared to other reported methods that utilize a large number of test experiments to define optimized reaction conditions. Synthesis of particles in the size range of 27–100 nm with relative standard deviations in size of <13.3% was demonstrated by application of this strategy.