When washing dishes with dishwashing detergent, the fat or grease from the dishes undergoes a process called emulsification. Dishwashing detergents contain surfactants, which are compounds that help break down grease and oil. These surfactants have hydrophilic (water-loving) and lipophilic (fat-loving) properties.
When you apply dishwashing detergent to greasy dishes, the surfactants surround and bind to the fat molecules. The hydrophilic part of the surfactant faces the water while the lipophilic part interacts with the fat, creating structures called micelles. The micelles suspend the fat or grease particles in the water, preventing them from re-depositing on the dishes.
When you rinse the dishes with water, the fat particles that are emulsified in the micelles get carried away with the water, effectively removing them from the dishes. The combination of surfactants, water, and mechanical action (scrubbing or spraying) helps to break down and remove the fat or grease, leaving the dishes clean.
It's important to note that while dishwashing detergents are effective at removing grease and fat, it's still advisable to scrape off excess food residue from dishes before washing them. This helps prevent clogs in your plumbing system and ensures optimal cleaning performance.