CHELATION

A Chelate is a coordination compound in which a central metal ion such as Ca2+ is attached by coordinate links to two or more non-metal atoms in the same molecule, called ligands. A Chelating Agent is one that “grabs” a metal ion at two or more points within the agent molecule.

 

By definition, INITIA™ Polymer Additives act as chelating agents with most muti-valent ions. However, using common use of the terms Chelate or Chelation tend to imply a more permanent or substantive relationship between the ion and the ligand where stoichiometry is exact and predictable (i.e. Calcium-EDTA.) INITIA™ Polymer Additives generally do not meet the common definition because their association with metals are temporary and their functionality is sub-stoichiometric.

 

 

TAB HEADING – SIMPLIFIED DEFINITIONS

 

Additive Functionality Simple Definition
Threshold Inhibition Extension of solubility of an otherwise insoluble salt beyond its saturation limits using an additive at sub-stoichiometric levels.
Sequestration Complexation of a metal ion such that the ion does not retain its original reactive properties.
Chelation Formation of a compound in which a central metal ion such as Ca2+ or Fe2+ is attached by coordinate links to two or more non-metal atoms in the same molecule.
Stabilization Colloidal Stabilization is where precipitation of a substance occurs but the additive prevents agglomeration of particles beyond 1 micron in size. Stabilization can also be a synonym for sequestration where coordination complexes between the additive and soluble ions or forming crystal lattices are formed and prevention of precipitation is achieved.
Particulate Dispersion Particulate Dispersion is a suspension of particulates in an aqueous solution. These can be Inorganic (i.e. calcium carbonate), Organic (i.e. biomass) or a mixture of the two.
Crystal Habit Modification Crystal Habit modification is where a “poison” such as a polymer, phosphonate, or other contaminant disrupts normal formation and produces crystals that either tend to re-dissolve or precipitate in abnormal forms.