eli5: why does white glue turn transparent after drying?
In: Chemistry
PVA glue is a mixture of water and the PolyVinyl Acetate molecules. These two don’t mix, forming microscopic balls of each. Light gets bent on all the boundaries between the different materials causing it to scatter in all directions. Making it opaque.
When it dries, the water evaporates and you’re left with just PVA. Since there are no boundaries, light passes straight through.
You can test it yourself by mixing vegetable oil and water in a glass, and then mixing it up. The oil forms tiny droplets in the water and it becomes cloudy and opaque. Wait for it to settle and it becomes clear again as the number of boundaries decreases.
Latest Answers