But I don't know if you've thought about it. Eggshell is actually a magical thing. While protecting the chicken, it must ensure that the chicken can break out of its shell without being trapped inside. How can it grasp this degree so well?
Scientists have just discovered recently that the secret of the success of eggshells lies in their complex nanostructures and structural changes when eggs hatch.
In terms of quality, 95% of eggshells are calcium carbonate. In one experiment, the egg shell was dissolved in vinegar, and the reaction between calcium carbonate and vinegar was neutralized, and the egg shell disappeared, leaving only a film inside the egg.
But the remaining 5% also contains hundreds of different protein, and these protein will affect the crystallization of calcium carbonate.
On March 30th, the researchers published a paper in the journal Science Progress, pointing out that the interaction between mineral crystals and protein initially produced an eggshell with anti-crack characteristics. With the passage of time, this eggshell will be adjusted at the nano level, and finally chicks can peck it and break it.
The eggshell is very smart. At first, it grew strong to protect the chickens inside. Then change the nanostructure over time to make the eggshell easy to break, so that the chicken can peck out the shell easily.
The researchers used ion beams to cut the thin cross section of eggshells. Then they use electron microscope and other high-resolution imaging techniques for analysis.
The researchers found that protein played an important role in it, because it would destroy the crystallization of calcium carbonate.
The researchers selected the broken eggshell and observed it at high resolution, and found that the crystals that looked neat at low resolution were actually more dispersed mixtures.
For example, the structure of an eggshell is like a wall. Some places are dense and firm, and some places are loose and fragile, so they must be loose and easy to form cracks. The same is true of eggshells. In the messy crystals, the cracks in eggshells must be jagged.
In order to verify this conclusion, scientists conducted a simulation experiment in the laboratory. They extracted the key protein osteopontin from eggshells and added it to calcium carbonate, resulting in crystals similar to those found in eggshells.
Mark McGee, a biomineralization researcher at McGill University, and his colleagues found that the formation of eggshell nanostructures was attributed to this protein.
The research team also found that although the eggshell is only a third of a millimeter thick, it must be divided into an inner layer and an outer layer! There are relatively few osteopontin in the inner layer, which will form loose nanostructures, mainly where chickens are nourished.
There are more osteopontin in the outer layer, because it is necessary to form a denser nanostructure to make the eggshell strong, so it can be used as a shield for chickens.
As the chicken in the shell grows bigger and bigger, the inner layer of the shell will dissolve through chemical reaction, releasing calcium for the chicken to absorb to develop bones.
They compared fertilized eggs hatched for 15 days with unfertilized eggs. With the passage of time, the inner shell in the fertilized egg gradually becomes smaller, but the unfertilized egg remains unchanged.
1? This change makes the inside of the eggshell potholed and extends more surface area. Researchers believe that this provides more space for dissolving chemical reactions.
This reaction will also make the whole eggshell thinner, thus making it easier for chickens to break out of the eggshell when they hatch.
According to the researchers, these discovered imaging technologies are of great help, and technological progress gives scientists the opportunity to explore these tiny creatures. This new research can provide more inspiration for designing new materials with specific properties.