Strictly speaking, the term “dehydration” is used to describe the removal of water. Each of the six different groups of samples being considered in this book may be damp, wet, or critically associated with water. In addition, some samples may be associated with non-aqueous liquids such as organic fluids, oils, and polymers. Conventional SEM demands that water and organic fluids either must be removed from samples or immobilized before they are examined and analyzed.
It is more usual (and more convenient) to first dry the sample before it is exposed to the arid environment of the microscope column. Drying hard robust materials such as metals and rocks is a relatively straightforward procedure. The surface water may be absorbed by soft paper or fabric tissue, taking care not to disturb the sample surface structure, and then allowing the remaining water to evaporate.
Much more attention has to be paid when drying organic materials, polymers, biological samples and, not...