The crystallisation of zeolites and other microporous materials in space has attracted some attention in recent years, in the search for larger or more "pure" and perfect crystals. Hydrodynamics and hydrostatics of zeolite synthesis solutions are strongly influenced by gravitational force, and the growth of zeolites in solutions which are effectively free from convection and sedimentation in micro-gravity may produce crystals of different character to those grown on Earth. The exact nature of the changes which occur on synthesising zeolites in micro-gravity depends upon the chemical and physical properties of the solutions as well as the "quality" of micro-gravity. The results from several experiments performed in space are summarised and discussed, and a few suggestions are made concerning possible improvements in experimental design and strategy.
- Crystal growth
- Zeolite synthesis