Formation of ice microparticles in cryoprotective solutions

Resumo

The formation of ice microparticles in 0.2-mm thin layers of aqueous solutions of cryoprotective agents cooled to temperatures reaching–196°C was studied. The shape and size of ice microparticles were determined by cryomicroscopy. At temperatures below 0°C, the formation of solid ice masses was observed; further cooling caused ice fracturing induced by emerging thermomechanical stresses and the formation of microparticles. The shape and size of the particles depended on the composition of the frozen solution and on the rate of cooling. The components of cryoprotective solutions (cryoprotectants, egg yolk, sugars, and lipids) significantly changed the shape and size of the ice microparticles.