This project focuses on the development of new experiments for the World of Materials course for nonscience majors that is also mandatory for elementary education majors. The course explores the chemistry of familiar materials from everyday life--paper, fabrics, metals, plastics, glass, leather, etc.--and discusses the life-cycle of each material from its source in the animal vegetable, or mineral world, through the stages of its processing to finished products, to its demise when it becomes used up or worn out and its ultimate fate in disposal or recycling. The new experiments allow students to observe microscopic and atomic-scale images, to carry out some pertinent chemical transformations, and to measure some important physical properties of these materials. The students work in teams of three to interpret these observations, reactions, and measurements and to draw correlations among them. For example, in one experiment the atomic structures of the surfaces of gold and graphite observed using a scanning tunneling microscope is correlated with their vastly different densities. In another experiment soda-lime glass is made by heating a mixture of sand (SiO2), soda ash (Na2CO3), limestone (CaC03), and cullet (crushed glass) in a benchtop muffle furnace. Small amounts of different transition metal carbonates (CoCO3, NiCO3, Ag2CO3, etc.) are added for color and the effects of transition metal concentration and furnace atmosphere on that color will be assessed. In a third experiment synthetic fibers like nylon monofilament fishing line is tested for its tensile strength and the resulting stress-strain curves correlated with solvent pretreatment and average molecular weights. Experiments like these allow students to observe atomic structure, experience real world chemistry, and draw their own conclusions about structure-property relationships in materials helping them to understand and appreciate why different materials behave the way they do.
