Abstract
Silica formation is an event that takes place in the biological and industrial world. Marine biological systems annually process 6.7 gigatons of “Si”. In industry, silica is used for a plethora of applications (filler, drug excipient, catalyst support, etc.), but in water treatment systems it is a problem, as it forms undesirable precipitates and deposits. It is, therefore, imperative to combat the problem of precipitation/deposition by approaches that focus on the stabilization of soluble forms of silica (mainly monosilicic acid, Si(OH)4). Among the various approaches the use of chemical inhibitors is the most effective strategy. Additives are being utilized successfully for several inorganic mineral scales (eg. CaCO3, BaSO4, etc.), however, silica is a case with intriguing idiosyncracies. Its control requires designed strategies based on its unique chemical nature. Thus, additives that are efficient for other mineral scales are totally ineffective for silica. We have devised chemical approaches to combat silica scaling in water systems, which include utilization of polyelectrolytes possessing “active” chemical moieties, capable of stabilizing silicic acid. These polymers reduce the rate of silicic acid condensation, and influence silica particle growth. Possible mechanisms are discussed, focusing on the nature of chemical moieties responsible for the stabilization.