How can nailpolish stay on your fingernails?

Nail polish stays on your fingernails through a combination of physical adhesion, chemical bonding, and evaporation. Here's a detailed explanation of each factor:

1. Physical Adhesion:

- When you apply nail polish, it physically adheres to the surface of your nail. The adhesion occurs between the polymers in the nail polish and the keratin molecules present in your nails.

2. Chemical Bonding:

- Some nail polishes contain ingredients that form chemical bonds with the keratin in your nails. These ingredients, such as formaldehyde and toluene, create a more durable bond, enhancing the adhesion of the polish.

3. Evaporation:

- After applying nail polish, the volatile solvents in the polish evaporate quickly, leaving behind the color pigments and polymers. This rapid evaporation facilitates the drying process and contributes to the polish's ability to adhere to the nail.

4. Base Coat and Top Coat:

- Many people use a base coat before applying nail polish and a top coat afterward. These additional layers enhance the polish's adherence and durability. The base coat creates a smooth surface for the nail polish to adhere to, while the top coat acts as a protective layer, preventing chipping and peeling.

5. Curing with UV Light (Gel Polish):

- Gel polishes require curing under a UV or LED light after application. This light activates the photoinitiators in the gel, causing them to form cross-linked polymers that harden the polish, resulting in a long-lasting, chip-resistant finish.

By combining these factors, nail polish effectively stays on your fingernails until you remove it with nail polish remover or it eventually wears off over time.