Lab Research to Engineer a Phosphorescent Bioplastic
Glowing Star Wars character toys created by students who experimented with variations of phosphorescent bioplastics in their lab research.Copyright 2016 Jamie Sorrell, RET Program, School of Polymers and High Performance Materials, University of Southern Mississippi
Students gain first-hand experience with the steps of the scientific method as well as the overarching engineering design process as they conduct lab research with the aim to create a bioplastic with certain properties. Students learn about the light mechanism that causes ultraviolet bead color change, observe the effect of different light waves on a phosphorescence powder, and see the connection between florescence, phosphorescence and wavelength. Students compose hypotheses and determine experimental procedure details, as teams engineer variations on a bioplastic solid embedded with phosphorescence powder. The objective is to make a structurally sound bioplastic without reducing its glowing properties from the powder embedded within its matrix. Groups conduct qualitative and quantitative analyses of their engineered plastics, then recap and communicate their experiment conclusions in the form of a poster, slides and verbal presentation. As an extension, teams make their own testing apparatuses. As a further extension, they combine all the group results to determine which bioplastic matrix best achieves the desired properties and then “manufacture” the optimum bioplastic into glowing toy figurine end products! Many handouts, instructions, photos and rubrics are provided.
Solar cells and solar panels are becoming common on rooftops, parking lots, solar farms, light-up street signs, moving gates, calculators, sidewalk night lights, and recharging devices. Inorganic solar cells, the most common cells used in solar panels, are considered efficient because they absorb a significant amount of energy from the sun. Yet, they are unable to turn all of the sun’s electromagnetic spectrum into usable energy; they are unable to convert most of the infrared and ultraviolet light. Inorganic solar cells are also expensive, large and stiff.
Newer technology organic solar cells are cost effective, flexible and compactable, which means they are even more useful for a wide variety of applications. However, organic solar cells are less efficient than inorganic cells because they absorb even less energy from sunlight than inorganic solar cells. So engineers are researching and experimenting with new manufacturing methods to improve the efficiency of organic solar cells.
Since solar cells are composed of coated layers with each layer responsible for absorbing certain light wavelengths, researchers are focused on synthesizing new layers to incorporate into solar cells that can absorb light wavelengths that current solar cells cannot. The design objective is to increase the energy efficiency of organic solar cells while keeping the cost effectiveness and mechanical properties that make organic solar cells so desirable.
In this activity, students are involved in a design challenge that is similar to this solar cell design challenge—to engineer a bioplastic that exhibits specific physical characteristics. In their lab research, groups isolate and experiment with varying different independent variables in the composition of a phosphorescent bioplastic, aiming to find a chemical composition that best meets the desired material properties.
After this activity, students should be able to:
- Investigate the effects of various light (UV, infrared, visible) on phosphorescence.
- Define phosphorescence, florescence and electromagnetic spectrum.
- Distinguish between independent and dependent variables.
- Create a phosphorescence bioplastic.
- Test the various concentrations of the components found in bioplastic (corn starch, water, vinegar, glycerin) to determine if a change in concentration inhibits or strengthens its phosphorescence.
- Perform qualitative and quantitative analysis.