Formation mechanism of liquid inclusions in dicumyl peroxide crystals

Abstract

A formation mechanism of crystal defects was proposed by investigations about the factors affecting the formation of macroscopic defects in dicumyl peroxide solution. The effects of crystallization parameters such as the solvent, temperature and supersaturation on the formation of crystal defects were studied in a targeted manner. A mild crystallization environment was beneficial to reduce the formation of defects during the crystal growth process. A self-made device was designed to study the effect of gas bubbling on the growth of dicumyl peroxide crystals. Experiments indicate that degassing of the solvent will lead to a sharp drop in the crystal growth rate and reduce the liquid inclusions inside the crystal. The enrichment of carbon dioxide in the solution was conducive to the formation of macroscopic defects. Through hot-stage optical microscopy, it can be proved that the fluid inclusions will transform into “negative crystals” when heated. Through molecular dynamics simulation on the surface structure and the adsorption mechanism, it is found that during the crystal growth process, the rapid growth of some of the dicumyl peroxide crystal faces and the adsorption of impurity particles may be the main reasons for the formation of liquid inclusions.