Method and apparatus for preparing slurry specimens for cryo-scanning electron microscopy

A method of preparing specimens of cement compositions for cryogenic scanning electron microscopy analysis of the hydration characteristics of said cement compositions, comprising the steps of:

• preparing a specimen of a cement slurry and placing a quantity of said slurry in a specimen support capsule;
• allowing said specimen of said cement slurry in said capsule to hydrate for a predetermined period of time;
• after said predetermined period of time, immersing said capsule containing said specimen in a cryogenic fluid to freeze said specimen at a temperature less than about -196.degree. C. to arrest said hydration of said cement composition;
• transferring said specimen from said capsule to a holder without exposing said specimen to atmospheric pressure, room temperature and humidity conditions;
• placing said holder containing said specimen on a support member disposed in a housing which is evacuated and frozen to prevent thawing of said specimen;
• and
• fracturing said specimen to expose an uncontaminated surface of said specimen for examination by a scanning electron microscope.

A specimen preparation housing for use in conjunction with a scanning electron microscope for cryogenic scanning electron microscopy of specimens of frozen slurries of compositions of matter, said specimen preparation housing defining a closable chamber for receiving a specimen, and said housing including:

• a specimen holder for holding a specimen;
• a support member having guide surfaces formed thereon and cooperated with surfaces formed on said specimen holder for supporting said specimen holder, said support member disposed in said chamber and connected to a source of refrigeration outside said chamber to reduce and maintain the temperature of said specimen holder and said specimen during presence of said specimen in said chamber;
• means for inserting said specimen holder and said specimen into said support member in said chamber;
• and
• means for fracturing said specimen in said chamber including an actuating rod for effecting actuation of said means for fracturing upon placement of said specimen in said chamber to expose an uncontaminated surface of said specimen after placement of said specimen in said chamber.