Any interface of chemical compounds represents a solvation shell. Water solvents are better known as hydration shells, even though the majority of people call them solutions. But that kind of solvent can’t be genuinely considered a shell if there isn’t another element that will interact with water.
For example, you can take the metal as it can represent a sample of attraction on the electrostatic basis. If that metal is the cation, then the electronegative oxygen atom would be attracted to the positive charge of the metal. This creates a shell of water molecules. The thickness of the molecule shell depends on the load, spatial dimensions, and distribution.
Hydration shell and how it reacts with starch
It is hard and complicated to list all details regarding solvation shells without using a plethora of complicated words that only one in ten people understand. But, using an example makes it easier to share the info in a way people will understand it without any problems. The previous case dabbled in the reaction of water with the positive metal ion. Even better example (and one more accessible to explain) would be the interaction of water molecules with starch, or to be more precise, glycogen, which is found in starch.
The hydration shell works with starch in several exciting ways due to the very nature of the starch. This example sees massive attraction due to the charge of the glycogen. The interaction is also attractive due to the high number of small charges.
The interaction between these two creates physiological consequences because the glycogen has a high dose of glucose that is ready to interact with water molecules. The implications of the interaction involve an increase of the mass and the bulk of glycogen as it attracts water. The amount of water molecules it can draw is limited, but that limit is extremely high as the glycogen molecule will expand three times in its size.
This is different than the reaction water has with oil molecules. In the majority of these interactions, the solvent shells either can’t be formed, or their thickness doesn’t exceed one or two molecules.