THE EFFECT OF ETHYLENE-GLYCOL ADDITIVE AND GROWTH-RATE ON THE CAPTUREOF WATER BY POTASSIUM ACID PHTHALATE CRYSTALS

The types and quantities of the volatile products formed in cleavage o f potassium acid phthalate crystals were detected by mass spectroscopy . The crystals analyzed were grown by conventional and fast-growth tec hniques from a nominally pure solution and from a solution containing 0.2 wt % ethylene glycol additive. It was found that the amount of wat er released from the cleavage surface was reduced from 5.6 x 10(15) to 2 x 10(14) molecules/cm(2) with an increase in the growth rate from 0 .2 to 2 mm/day, and to 6.6 x 10(13) molecules/cm(2) with the addition of ethylene glycol. This effect was attributed to the fact that an inc reased growth rate and the presence of ethylene glycol hinder ordering of the adsorption layer and, therefore, make the capture of adsorbed water less probable.