A rapid preparation technique for studying highly water-swollen membranes with a scanning electron microscope (SEM) supplied with a cryo-unit.

In this study the cryo-unit is introduced as a new and useful instrument to investigate water-containing specimens with the SEM. Often water-containing biological specimens are studied, but in our case we used water-swollen polymer membranes. The results show that application of a cryo-unit permits the study of this material at low temperatures up to magnifications of about 10 000 times, while other techniques failed to give reproducible results.