CRITICAL GROWTH-RATES OF ADVANCING ICE WATER INTERFACES FOR PARTICLE ENCAPSULATION

A cryomicroscope with a special gradient freezing stage similar to the Bridgman technique, has been used to study the critical encapsulation velocities of small spherical particles. Different materials and sizes between 2 and 20 μm diameter were investigated under controlled conditions, i.e. a macroscopically planar ice-liquid interface advancing with defined velocity and imposed thermal gradient. The experimental data were related to theoretical models and clearly show a functional dependence on temperature gradient (Vc∝G 1 4), particle radius (Vc∝R-1) and particle surface structure, but further results are needed to consolidate the models. © 1990.