They both use release agents. Bakers use shortening or a nonstick coating on pans, and road repair workers use nonstick coatings in the trucks. In this activity, students investigate several compounds to determine how well they act as release agents. Science and Technology Standards Abilities of Technological Design Students identify appropriate problems for technological design. Students implement a proposed design, using models to simulate the inside of an asphalt truck and a sign with graffiti.
Students evaluate completed technological designs.
Scientific Inquiry Students conduct a scientific investigation to determine which compounds are the most effective release agents. The characteristic property of release agents is that they prevent sticking by changing the properties of the surface to which they are applied. The selection and application of release agents depend on the intermolecular interactions between the release agent, the surface, and the substance one wishes to prevent from sticking. Oils are carbon-containing molecules which are not soluble in water and thus are useful as release agents. Cultural preferences determine what products scientists develop and the characteristics of the products.