Dishwashing liquid harm household silver, fine glassware, anything with gold leaf, disposable plastics, and any objects made of brass, bronze, cast iron, pewter, tin, or wood, especially when combined with hot water and the action of a dishwasher. When dishwashing liquid is used on such objects it is intended that they be washed by hand. Hand dishwashing detergents utilize surfactants to play the primary role in cleaning. The reduced surface tension of dishwashing water, and increasing solubility of modern surfactant mixtures, allows the water to run off the dishes in a dish rack very quickly. However, most people also rinse the dishes
Polymer adsorption used in conjunction with the following equation to determine the relationship between contact angle and surface energy of the solid, as surface tension ≈ surface energy for a solid: where Using these two equations, the surface energy of a solid can be determined simply by measuring the contact angle of two different liquids of known surface tension on that solid's surface. For heterogeneous surfaces (consisting of two or more different types of material), the contact angle of a drop of liquid at each point along the three phase contact line with a solid surface is a result of the surface