Inhibition of the rates of nucleation and growth of hexanedioic acid crystals by related compounds
Hexanedioic acid (Adipic acid) precipitation from aqueous solution at 25 °C was followed thermometrically. The precipitation was preceded by a long induction period, where no precipitate was observed; more than half of the total possible precipitate formed during the following period of the same length. The rate of precipitation depends on the stirring rate, and the majority of the crystals originate from secondary nucleation. Trace amounts of alkanoic acids and alkanedioic acids with less than 12 carbon atoms inhibit the precipitation strongly, perhaps by slowing down the rate of growth. Trace amounts of alkanoic acids with more than 13 carbon atoms catalyse the precipitation.