PREPARATION AND USE OF SOLID BEADS HAVING CONTROLLED CHARACTERISTICS

摘要

Processes for preparing and using controlled characteristic beads are disclosed, the process of making the beads including the steps combining at least one monoethylenically unsaturated monomer with a polyethylenically unsaturated monomer and a monomer-soluble initiator to form a monomer phase; combining the monomer phase with a liquid in which the monomer phase is substantially immiscible to form a reaction mixture such that when the monomer phase is vinyl in nature the liquid also includes a high molecular weight, high charge density surfactant, and when the monomer phase is acrylic in nature the liquid includes an organic polymer colloid suspending agent; agitating the reaction mixture at an initial speed and temperature for a time sufficient to homogenize the reaction mixture, thereby producing first intermediate droplets, and subsequently reducing the agitation speed to a level sufficient to allow limited coalescence of the first intermediate droplets to form second intermediate droplets having size distribution with less than about 30 % variance from the mean; and polymerizing the second intermediate droplets to form solid, substantially non-porous beads. One method of using controlled characteristic beads includes combining the beads produced by the process with a sample containing two separable components and centrifuging the sample for a time and at a rate sufficient to produce distinct bands of components.