Colloidal silica is one of the most unwanted deposits in the water treatment industry. Its control is a
complicated issue and the decision on which control method to apply is frequently based on a number of
factors. Our goal is the discovery, design and application of organic additives (preferably “green” and
environmentally friendly) that have some effect on silicate polymerization. This paper reports the
inhibition efficiency of a variety of polymeric additives and some combinations in retarding silicate
polymerization is supersaturated aqueous solutions. There are three classes of polymeric additives
studies: (1) neutral, (2) cationic of varying positive charge density, and (3) combinations of anionic and
cationic polyelectrolytes. As a neutral polymer PEOX (poly(2-ethyl–2–oxazoline)) was tested. Cationic
additives included PEI (polyethyleneimine), PALAM (polyallylamine) and PAMALAM
(poly(acrylamide-co-diallyl-dimethylammonium chloride)). Blends of cationic/anionic polymers were
PEI+CMI (CMI = carboxymethylinulin), PEI+PAA (PAA = polyacrylate)). All aforementioned
additives and/or blends exhibited inhibition features from “good” to “excellent”. Inhibition efficiency
was found to depend on a multitude of factors, such as cationic charge density, inhibitor dosage, time,
etc.