The spontaneity of crystals
A crystal is a solid with its atoms, molecules or ions arranged in a very ordered microscopic structure, forming a three-dimensional network. The science that studies crystals is crystallography, and allows us to know their chemical and physical properties.
One of the most common crystals that we find in nature is the snowflake. Each one has a different shape, more or less starry, that branches fractally (the same pattern is repeated at different scales), on a hexagonal base. The two environmental factors that determine the shape of the flake are the temperature (between -5 and -35 ºC) and the degree of supersaturation of the water vapor in the cloud. From the combination of these two factors, plate-shaped or column-shaped crystals, more or less stellate, arise spontaneously.
The minerals also have a crystalline structure of great beauty, some examples are: Iceland spar (calcium carbonate), pyrite (iron sulfide), desert rose (calcium sulfate), or hyaline quartz (oxide of silicon). All of these crystals form spontaneously under certain physico-chemical conditions. We can verify this with a simple crystallization experiment. It will be necessary to prepare a solution of sodium acetate (CH3COONa) in distilled water in a ratio of 100:30, in a water bath. We will then obtain a supersaturated solution, which when it cools will crystallize spontaneously in the event of any disturbance, due to the fact that it is in an unstable equilibrium. The crystallization reaction releases energy and achieves a stable balance.
The different viral particles self-assemble inside the host cell in a process similar to crystallization, since, like crystals, they constitute structures that are in a minimal state of free energy (ΔG). Consequently, in addition to current antiviral therapies based on a pharmacological strategy, a thermodynamic strategy could be adopted in order to modify the free energy (ΔG) and make the viral assembly non-spontaneous. Even the most lethal viruses cannot overcome the laws of physics.