What is the primary mechanism by which phosphonate scale inhibitors prevent scale formation?

Phosphonate scale inhibitors primarily prevent scale formation through a combination of threshold inhibition and crystal distortion. Threshold inhibition refers to the ability of phosphonates to prevent scale formation at substoichiometric concentrations, meaning they can inhibit scale even when present in much smaller amounts than the scaling ions (like calcium or barium). This occurs because phosphonate molecules adsorb onto the surface of the nascent (newly forming) scale ....