Crystals and their uses
Crystals for bone replacement
Studies of the chemical composition of bones and tooth enamel were quite perplexing for the first researchers. These chemical compounds are very reactive nano-crystals known as apatites. By means of artificial biomineralization, Man has been able to create crystalline prostheses which imitate nature.
Crystals and their defects in metallurgy
Metallurgy is the sudy of metals, intermetallic compounds and mixtures thereof known as alloys. The first evidence of human metallurgy dates from the 5th and 6th centuries BC. They have numerous uses ranging from steel in construction to complex alloys used in modern jet engines to coatings that confer corrosion resistance. It is often the defects in metals and alloys that determine their very useful electrical and mechanical properties.
Crystals for pharmaceutical applications
The same molecule can crystallise in different forms while presenting the same chemical characteristics in solution. This polymorphism results from a different arrangement of molecules. In pharmacy, it is important to control the shape and size of the crystals that contain the active molecule of the medicine, because these parameters may influence the dissolution rate and thus have an effect on the effectiveness of the medicine.
Liquid crystals!
A liquid crystal is a phase between the liquid and the solid state: it flows like a liquid but has the properties of a solid. The molecules of a liquid crystal are highly elongated and have a tendency to line up like matches in a box. They owe their name to their optical properties which are similar to those of regular crystals.
