Demo A Day IV

Dean J. Campbell, Bradley University, Peoria, Illinois

Demonstrations and Props Used in Materials Chemistry Class

Classroom demonstrations have long been an approach used to convey information in chemistry courses. The intent is to help student learning by providing physical or video examples to illustrate concepts described in class. It has been my goal to show at least one of these examples per class meeting time in all of my courses. I have been mostly successful in recent semesters, since there are so many connections that can be made. It does help to write down what examples are used for each course and then refer to the list in subsequent offerings of the course. Many examples from Fall, 2023, and other offerings of Materials Chemistry are briefly described below. Many of these examples are also suitable for use in high school and collegiate General Chemistry courses, and other chemistry courses.^1,2,3 My motivations for these examples are also described in the list below. The examples are categorized by their fit to sections of the course, which in part align with content in recommended textbooks for the course.^4,5 This seemed to be a good starting point for categorizing the examples, recognizing that many of them fit into multiple categories.

The descriptions are rather terse, but some of them might become integrated into future blog posts, or already have been posted elsewhere. Videos describing many of these examples are posted on the YouTube channel Chem Demos. These videos have been organized into categories, along with some discussion-promoting questions, on a Bradley University Chemistry Club Demo Crew website:⁶ 

 

Introduction to Materials Chemistry and Green Chemistry

Deer jaw – A deer jawbone and teeth are made of natural biocomposite materials that could be used by humans and could also inspire humans to produce other materials.

Burs and Velcro – Burs are seeds made of natural biopolymer plant material with hook structures that stick to fur and clothes (Figure 1). They inspired a petrochemical polymer material with hook structures that are used as fasteners.⁷

Figure 1. Burs sticking to clothes and fur.

 

Poisson’s ratio examples – Most materials have positive Poisson’s ratio – they get thinner as they stretched, including rubber bands, metals, and chewing gum. A few structures can have a negative Poisson’s ratio – getting wider as they are stretched, including Hoberman spheres and reentrant foams. Some materials can be structured to do either, like paper cutouts and LEGO brick structures.^4,8

Chewing gum (thought exercise) – Students were asked to imagine themselves stretching chewed up gum from their mouths (most of this have probably done this at some point in our lives). Stretching the gum just a little and letting it snap back into shape represents elastic behavior. Stretching the gum further and letting it snap back but it does not return completely back into shape, represents plastic behavior.

Deformation with Vernier materials tester – Wire coat hanger was bent in a Vernier materials tester connected to a LabQuest module. The module displayed stress-strain curves to illustrate elastic behavior, and then plastic behavior with greater hanger deformation.

Glass vs plastic vs iron degradation – Variation in materials resistance to weathering illustrated by old lamp stand found in the woods which exhibited rusting of iron portions, some degradation of plastic portions, and no apparent degradation of glass portions.

Metal beverage can degradation - Variation in metals resistance to weathering illustrated by beverage cans containing iron, which showed obvious corrosion, and aluminum, which did not.

Polystyrene vs starch packing peanuts – Both types of packing peanuts were added to water to show the degradability of starch and the persistence of polystyrene in the environment.⁹  

New vs old polyethylene bottles – Shown to illustrate the oxidative degradation of polyethylene. The new bottle was more flexible when squeezed, and the old bottle was more brittle when flexed, with small pieces of plastic (microplastics) breaking off.

E-factor from 3D printing - Showed a model produced on a 3D printer as well as the scraps of the supporting material that were produced by the printer. The mass of the waste was divided by the mass of the product to obtain the E-factor, and the advantages and limitations of this approach were discussed.¹⁰

 

Crystal Structures and X-ray Diffraction

Penny packing – Bags of pennies were distributed to the students for them to experiment with various packing arrangements (square, closest packing, etc.) on desk surfaces.

Crystal models – Various models, including ball-and-stick and space-filling, to describe various metallic, ionic, and network covalent crystal structures as extended and unit cell structures. Some of the models had representations of planes crossing through the atoms in order to highlight particular (hkl) lattice planes.

3D printed carbon structures – Showed 3D printed models of several carbon allotropes: graphite/graphene, diamond, lonsdaleite, carbon nanotube, and C₆₀ fullerene.¹⁰

Visit to rock collection – Took the students to visit the mineral display on campus to show how arrangements of atoms within crystals can influence their macroscale structure.

Diffraction of visible light – Various principles of Bragg diffraction of X-rays by atoms can be simulated by Fraunhofer diffraction of light sources. Principles include the influences of wavelength and scattering feature spacing on diffraction pattern spacing. Light sources include white light and lasers. Objects used to produce the diffraction include diffraction gratings, compact disks, sheer fabric, and others.

Other optical diffraction structures – Used to illustrate examples and applications of optical diffraction and structural color, including photonic crystal films, opals, Morpho butterfly wings, and peacock feathers.¹¹    

 

Metals

Deformation of metal paper clips – A paper clip is opened. Bending the clip just a little, with metal atoms slipping just a little out of position, and letting it snap back into shape represents elastic behavior. Bending the clip further, with metal atoms slipping into new thermodynamically stable positions, and letting it snap back but it does not return completely back into shape, represents plastic behavior. Flexing the paper clip back and forth accumulated dislocations in the wire (work-hardening) and made the paper clip more brittle and more likely to break.

Egg crate or paper cutout slip plane models – Paper cutouts of rows of circles or the rows of bumps in egg crate contains can represent layers of atoms on the surfaces of slip planes. Two of the models can be held in close contact and moved past each other to simulate elastic and plastic deformation along metal slip planes.¹² 

Atomic trampoline – Bounced metal balls off uncovered cylinder of a crystalline stainless steel surface and a plate of amorphous metal alloy glued to a cylinder of stainless steel. The balls bounce higher from the harder amorphous (glassy) metal surface, because dislocations propagate less easily through the non-crystalline alloy.¹³     

BB board – Iron “BB” ammunition spheres were placed between two sheets of heavy transparent plastic, sufficient to partially fill the space between the sheets. The assembly was laid flat on a document camera and the spheres were initially free to move around to simulate metal in a liquid state. The assembly was quickly raised up a little bit on one side and the spheres all rolled to the opposite side to simulate rapid freezing of the metal and produce small ordered crystalline regions (grains) of spheres. When the tilted assembly was gently tapped with a hand, spheres along the grain boundaries were jostled into new positions, causing many small grains to shrink and many large grains to grow, simulating metal annealing. When beads that are smaller than the BBs are added to the assembly, their different sizes interfere with the growth of the ordered regions. Similarly, atoms of differing sizes can be used to produce non-crystalline metals. Video 1 shows a BB board in use.

Video 1. Using a BB board to illustrate crystals in metals. Chem Demos YouTube channel (accessed 1/25/2024).

 

Drawing of metal defects/dislocations – Showed a drawing from the Materials Science Companion that depicted various types of metal defects in polycrystalline metal. Dislocations, represented as being at the end of a half row of atoms, are best viewed by holding the picture at an angle and viewing along the guide arrows.⁴

Corn cob row dislocation – The end of a partial row of kernels between two complete rows is a model of a metal dislocation, which is the edge of a partial plane of atoms between two complete planes of atoms.⁴

Galvanized surface - Crystals in zinc coating appear as polygons with various shades of gray.

Wiggle-bug for mercury fillings – Donated by a local dentist and shown as an example of how component metals of a mercury-containing dental filling can be mechanically mixed together in the “wiggle-bug” shaker to produce an amalgam alloy. Also connected to human and environmental safety aspects of the use of these fillings.

Scanning electron microscopy and energy dispersive spectroscopy of coins – Coins were recognizable, electrically conductive objects that demonstrated the magnification capabilities of the microscope and the elemental analysis capabilities of the energy dispersive spectrometer.

 

Electronic and Magnetic Properties  

AgCl darkening in light – Showed AgCl before exposure to light (white) and after exposure to light (dark gray). The AgCl darkens as photons promote the transfer of electrons from chloride ions to silver ions, reducing them to elemental silver.

Gamma irradiated salt and marble – Showed NaCl and a glass marble that had been exposed to gamma rays. The materials darkened as the gamma photons moved electrons away from their thermodynamically most stable positions. Heating the irradiated NaCl on a hot plate caused it to glow orange as the electrons returned to more stable locations, and the salt was white when the process was complete. Video 2 shows this color change.

Video 2. Heating gamma ray irradiated sodium chloride. Chem Demos YouTube channel (accessed 1/25/2024).

 

Sand jar models of bands – Showed closed jars which represented electron energy bands, with sand that represented electrons.⁴ When the jar is empty, there is no sand to move around when the jar is tilted; similarly, an empty energy band contains no electrons to move around under an applied potential. When the jar is completely full, there is too much sand to move around when the jar is tilted; similarly, an energy band that is full of electrons will not allow those electrons to move around under an applied potential. When the jar is partially filled, there is sand that can move around when the jar is tilted; similarly, and energy band that is partially filled with electrons will allow those electrons to move around under an applied potential.

Electron/hole sliding tile puzzle – Modified a sliding tile puzzle to demonstrate the movement of electrons and holes in a semiconductor. Each tile was covered with an “e^-” to represent an electron. The surface under each tile had an “h⁺” written on it to represent a hole. As the electron tiles are moved in one direction, the location of the missing tile hole migrates in the opposite direction. Video 3 features this model.

Video 3. Modeling hole motion in a semiconductor using a tile puzzle. Chem Demos YouTube channel (accessed 1/28/2024).

 

Tissue paper banners – Folded and cut tissue paper banners to resemble a layer of alternating cations and anions. The ion sizes and banner colors illustrated the relationship between ion size, lattice energy, and bandgap energy. Cutting the banner and sliding the portions simulated the cleavage of ionic compounds.¹⁴

Copper-doped zinc sulfide screen – The screen illustrated multiple concepts associated with semiconductor optical properties. Many colors of light with lower energy than green light could not make the screen glow, whereas many colors of light with higher energy than green light could make the screen glow. The screen would glow the same color regardless of the excitation color of light (assuming it exceeded the minimum excitation energy). Red colored light could temporarily brighten and then darken the screen as that light could promote electrons out of energy traps to stimulate phosphorescence.¹⁵

Color mixing by three-color LEDs – Showed LED light source that contained red, green, and blue LEDs. By changing the relative intensity of light produced by each LED, different colors of light, including white, can be produced.

Blackbody radiation from incandescent light source – Used light emission from incandescent light bulb connected to a variable resistor to illustrate fundamentals of blackbody radiation and color temperature. When little electricity flowed through the bulb filament, producing relatively small heating, it had a reddish or orangish glow. When more electricity flowed through the bulb filament, producing more heating, it had a yellowish or whitish glow. Yellow-tinted light might seem warmer to the eyes than blue-tinted light, but the yellow-tinted light is produced by lower temperature black-body radiation than blue-tinted light.

White LED light sources – Showed light emission from light sources that were composed of blue LEDs that caused phosphors to emit green and red light. All of the light colors mixed together to produce white light, but varying amounts of phosphor materials varied the white color from yellowish (with a lower color temperature) to bluish (with a higher color temperature). Later in the course, students shined the bright white lights on their cell phones into a Vernier Fluorescence/UV-VIS Spectrophotometer to see the emission spectra from the blue LEDs and associated phosphor materials.

LED tea light in liquid nitrogen – The yellow glowing “flame” from an LED tea light was turned upside down and immersed in liquid nitrogen. The LED emission blue-shifted to a greenish color as the cold LED contracted and its atoms got closer together.⁴

Magnetic money – Older Canadian nickels contain sufficient ferromagnetic nickel metal to be picked up by a magnet. United States dollar bills contain sufficient magnetic material that they can be made to move under the influence of a strong magnet.¹⁶

Magnetite and dried ferrofluid – Showed a sample of magnetite (it can also be synthesized in class) and a sample of a commercially provided oil-based ferrofluid as an example of a superparamagnetic material. A pool of the fluid formed spikes on its surface as it tried to follow the field lines of an external magnetic field. If the fluid was dried in an oven, the spikes became permanent structures, which might have made them less likely to stain skin or clothing.¹⁶

Magnetic computer hard drive – Older computer hard drive can contain many magnetically interesting materials, such as neodymium iron boron magnets, magnetic memory storage, and magnetoresistive read heads.¹⁷

Flash rocks – Struck two pieces of polycrystalline quartz together with glancing blows. The covalent bonds broke in the quartz near the contacting surfaces, and these broken bonds reacted with nearby air to produce flashes. This was shown as a phenomenon where light energy was produced by crushing quartz that was NOT piezoelectricity (mechanical to electrical energy). In retrospect this might have worked better to illustrate the structure of a network covalent material.¹⁸

Polyvinylidene difluoride (PVDF) flicker strip – Waved a film of PVDF that had been electrically poled and covered on each side with metal. The metal was connected to neon light bulb. When the strip was waved, the piezoelectric charge buildup made the neon bulb flash.  

Green laser into polydimethylsiloxane (PDMS) containing gold nanoparticles – Shined a strong 532 nm green laser beam through a slab of transparent PDMS containing reddish colored gold nanoparticles. The laser light was absorbed by the plasmons of the gold nanoparticles, which heated the PDMS and caused a nonlinear optical distortion of the beam. As a result, the laser beam spot projected through the gold in PDMS expanded into concentric interference rings.¹⁹

 

Phases

3D phase diagram models – Showed 3D phase diagram models that related pressure, volume, and temperature (Figure 2).

Figure 2. Three-dimensional phase diagrams relating pressure, volume, and temperature for (LEFT) water and (RIGHT) carbon dioxide.

 

Ice models – Models of the three-dimensional structure of water hydrogen-bonded into the Ice Ih (hexagonal, more common) and the Ice Ic (cubic, less common) phases.

Porphyry – Showed examples of the igneous rock porphyry, which contained larger crystals of one composition of material embedded within a matrix of another composition of material.

YBCO superconductor – Immersed a disk of YBa₂Cu₃O₇-d into liquid nitrogen, then removed when cooled and levitated a strong magnet over the disk (could even insert a piece of paper in-between the magnet and superconductor). This illustrated the superconducting phase change and the Meissner effect.⁴

NiTi alloy ICE word – Phase changes associated with NiTi nitinol alloy were shown using a wire piece of the alloy that had been shaped into the word “ICE” (Institute for Chemical Education).⁴ The wire word was stretched out of shape, and then a heat gun was used to bring the alloy from its martensite phase temporarily to its austenite phase to enable the wire to re-form its original shape. Videos showing these sorts of nitinol transformations can be found online.²⁰

NiTi alloy ring/thud rods - Phase changes associated with NiTi nitinol alloy were shown by dropping rods of NiTi of very nearly the same composition on a hard surface. The austenite rod, with its more regular arrangement of atoms, rang. The martensite phase rod made a thud sound.⁴

NiTi alloy artery stent – Showed an artery stent made from NiTi nitinol alloy. The ability to interconvert between the martensite and austentite phases contributes to the superelasticity of the metal. A tube-shaped stent made from this metal can be compressed within another tube and moved to location within an artery. When the outer tube is removed, the superelastic stent can expand and prop open the artery.

 

Polymers

Plastics with resin codes 1 through 7 – Used in other courses, the polymer samples were all attached to one board with labels of the resin code and polymer name, this was done to show examples of polymers for each of resin codes 1 through 7.²

Polymerization by holding hands (thought exercise) – This was done this time as a thought exercise, but has been done in the past involving actual students. Students were lined up, divided into pairs, and then were asked to hold hands with each other. (As an alternative, the participants could hold ribbons instead of directly holding hands.) Each student represented a carbon atom, and each pair of students represented an ethylene molecule. The linked pairs of arms represented the carbon-carbon double bond, and the legs representing covalent bonds to hydrogen atoms. Then the instructor uses one of their own hands and goes to the first pair of students and takes one of their connected hands, breaking one of the paired student-student hand connections as a single hand connection forms between a student and the instructor. This simulates a free radical initiator adding to an ethylene and creating a longer free radical in the process of polymer chain initiation. The student that has a newly freed hand now goes to the next pair of students, breaking one of their paired hand connections and producing an even longer chain of people, representing a longer free radical in the process of polymer chain propagation. The process repeats until everyone is holding hands. If there is an unpaired person left, e.g., from an odd number of students in the class, this student hand can link with the free hand at the end of the chain and stop the process. This represents the polymer chain termination step. There are variations on these themes that have been explored over the years. For example, a chain of people holding hands and wearing conventional shoes can move about and bend rather easily, but addition of bulky footwear like snowshoes can diminish the mobility of the chain of people. This can simulate how use of bulky pendant groups on polymer chains, e.g., phenyl groups on polystyrene, can make the polymer more rigid.   Another variation that has been explored is placing two chains of people in parallel and connecting them by ribbons to simulate cross-linking polymer chains.   

Borax and white glue slime – Placed polyvinylacetate glue (white school glue) into large double-nested zip-seal plastic bags. Added a solution of borax dissolved in water, sealed the bags, and then handed around to the class. The students carefully kneaded the bag to mix the components so the borax could cross-link the polymer chains to make slime.  

Polylactic acid foam – Showed as an example of a greener polymer foam than polystyrene foam. 

Starch packing peanuts and water – Water added to the starch packing peanuts solvent-swelled the starch, enabling them to be solvent-welded (and dissolved if there was sufficient water). Also, as mentioned above, both starch and polystyrene packing peanuts added to water show the degradability of starch and the persistence of polystyrene in the environment.⁹  

Compact disk cases and acetone – Acetone added to compact disk cases solvent-swelled the polystyrene, enabling them to be solvent-welded.

Polyethylene terephthalate vs polystyrene container sound – Showed how polyethylene terephthalate container, with its softer polymer, makes a sort of dull thunk noise when flicked with a fingernail, but a polystyrene container, with its stiffer polymer, makes a sharper, brighter noise when flicked with a fingernail.

Paper cup with plastic foam – Showed as an example of a paper cup, which one might think of as being recyclable, which was integrated with a polymer (polyethylene?) foam covering, which might not be as recyclable.

Happy vs. sad balls – Dropped neoprene “happy” ball and polynorbornene “sad” ball from the same height onto a desk surface. The happy ball had a more elastic collision with the surface and bounced higher.²¹

Cotton cloth and paper – Showed as examples of natural cellulose polymers,

Ethylene-vinyl acetate foam sheet – Showed as an example of a copolymer.

Newspaper advertisement of polyester clothes – Showed as an example of polyester used as synthetic clothing fibers.

Picture of nylon damage from acidic flyash – Described the decades-old incident where sulfuric acid formed on ash particles that had been produced at a local coal-fired power plant and landed on nylon stockings, causing the polymer to break down as the amide groups were hydrolyzed. Showed a picture from the local newspaper of nylon stockings that were damaged in that incident.^2,22

WWI veteran picture – Near Veterans Day, showed a picture postcard of the author’s great grandfather dressed in a WWI uniform. Noted that phosgene was used in chemical warfare in that war, but is also used as a monomer in the production of polycarbonate.

Shrinky-dinks and sound change – A sample of a sheet of polystyrene was placed on aluminum foil in a toaster oven and heated. This heated the sheet above its glass transition temperature, enabling the polymer sheet to become more flexible and shrink in size while thickening. The hot sample was removed from the toaster oven with tongs and dropped repeatedly onto a hard countertop. The polystyrene initially made a dull thump noise while soft and heated above its glass transition temperature. When the polystyrene sample cooled down below its glass transition temperature, it hardened and made a clinking (glassy) noise.²³ 

Polypropylene cup glass transition in liquid nitrogen – Placed a polypropylene cup (contained a #5 resin code) into liquid nitrogen. This cooled the cup below its glass transition temperature, making it brittle and able to be crushed by hand soon after removal from the liquid nitrogen.²⁴ 

Polyacrylate artificial snow – Showed container of artificial snow made of powdered sodium polyacrylate polymer.  This ionic polymer can absorb water and solvent-swell, but as the water evaporates from the polymer it can feel cool to the touch. The class was shown that the packaging for the product also contained rather varied messaging about the safety of the product.

 

Silicates, Glass, and Ceramics  

Silicon carbide sample – Shown as an example of silicon carbide, which is structurally similar to diamond and elemental silicon.

Polydimethylsiloxane (PDMS, silicone) sample – Shown as an example of silicone. Its rubbery properties are a marked contrast with the brittle but similar sounding silicon and silica.

Asbestos, mica, and stilbite samples – Shown as examples of one-dimensional (chainlike), two-dimensional (sheetlike), and three-dimensional silicate and aluminosilicate structures.

Stained glass – Shown to illustrate the rich variety of colors that glass can take when various impurities are added. Even conventional soda-lime glass has a green tint from iron impurities.

Fluorescent glass and ruby – Shown as examples of silicon oxides and aluminum oxide containing impurities (like chromium in the case of ruby) that fluoresce when stimulated by ultraviolet light.

Glass and ceramic insulators – Power line insulators and spark plugs are examples of the electrically insulating capabilities of glass and ceramics.

Glass bottle with Peoria markings – Showed example of local bottle glassmaking from years ago

Ceramic honeycomb from catalytic converter – Support for catalytic materials shown as an example of glass ceramic and its high heat resistance.

Space shuttle tile – Showed glass fibers sintered together into very heat-resistant but also fragile material.

Gypsum – Crystals shown during discussion of the dehydration and rehydration of calcium sulfate dihydrate when working with plaster.

Results of cement heat study – Mixed cement in a polystyrene foam cup and added a stainless steel thermometer connected to Verrnier LabQuest module to track temperature as a function of time. The cement warmed as it cured, peaking a few hours after the cement was mixed, and then cooled back to room temperature. The experiment was described to the class as a description of the exothermic reactions in cement curing.

 

Engineered wood materials – Compared various wood materials to illustrate composite structure and properties

• piece of wood – single piece, long fibers in one direction, anisotropic strength
• plywood – carefully layered sheets, long fibers in various directions, isotropic strength
• oriented strand board – organized chip-like structure, intermediate length fibers, isotropic strength
• particle board – small chips, short fibers, isotropic strength

Lab activities day - Set aside a class time where students had the opportunity to work with various materials described in class. Students were allowed to work together on the tasks and answering the questions. Figure 3 shows some of the setup from the lab activities day, and a list of the activities follow.

Figure 3. Some of the activities for the lab activities day.

 

• Plaster – Powdered plaster was mixed with water and poured into silicone molds. As the calcium sulfate hemihydrate combines with water to make the dihydrate, the gypsum crystals that were formed interlocked to make monolithic plaster paperweights. Students were asked to write the chemical reaction for calcium sulfate hemihydrate with water.
• Solder – A soldering iron was used to melt solder and drip it into small silicone molds. A small piece of wire was inserted into the liquid in order to pick up the solder when it froze. Students were asked what were the melting points of pure lead, pure tin, and a 60% lead solder.
• Epoxy adhesive – Two-part epoxy adhesive was mixed and poured into small silicone molds. As the epoxide groups reacted with the amine groups, the polymer hardened. A challenge to watch out for is that if the components are not mixed properly, they might never completely cure. Students were asked to write a reaction between the functional groups in epoxy adhesive.
• Cement – Powdered cement was mixed with water and poured into shallow aluminum foil molds. Materials such as sand or yarn were added to try to alter the strength of the cured cement plates. After the cement was cured, the cement plate strength was tested by supporting it by its ends and placing a wooden block over the middle, and then textbooks were placed on the wooden block until the plate broke. Since only a few cement plates were made, and they varied in thickness, little useful data could be collected this time, but more careful, extensive data could be collected in the future. Students were asked to write the conventional formula and the cement shorthand for tetracalcium aluminoferrite.
• Polyurethane foam – Polyurethane foam insulation was dispensed into a tray, where the foam components reacted, expanded, and hardened. Students were asked to write the reaction describing how the urethane polymer forms.
• Prince Rupert’s glass drops – A gas-oxygen torch was used to melt the ends of a glass rod and drip the glass into water. When the drop quickly cooled, the interior of the drop was put under tension and the exterior of the drop was put under compression. The head of the drop did not break when struck with the hammer. However, breaking the tail of the drop with a pliers did not cause the drop to burst into tiny pieces. Perhaps the glass drop needed to be hotter before being dripped into water. Students were asked to explain why the drop resists smashing at the head and (should) break so easily at its tail. A video showing a successful Prince Rupert’s drop can be viewed here.

Video 4. Prince Rupert's Drops and Gorilla Glass. Chem Demos YouTube channel (accessed 1/25/2024).

 

Safety I have worked to maximize safety, but each demonstration and prop comes with its own particular set of safety considerations. If physical classroom examples are to be done in-person, then instructors must identify and respond to potential hazards, personal protective equipment, and disposal issues associated with these examples.

 

Acknowledgements This work was supported by Bradley University and the Mund-Lagowski Department of Chemistry and Biochemistry with additional support from the Illinois Heartland Section of the American Chemical Society. The material contained in this document is based upon work supported by a National Aeronautics and Space Administration (NASA) grant or cooperative agreement. Any opinions, findings, conclusions, or recommendations expressed in this material are those of the author and do not necessarily reflect the views of NASA. This work was supported through a NASA grant awarded to the Illinois/NASA Space Grant Consortium. Special thanks to Audrey Stoewer for developing the video website and the Prince Rupert's Drops video.

 

References

1. Campbell, D. J. “A Demo A Day: Demonstrations and Props Used in My General Chemistry Class.” ChemEd Xchange. https://www.chemedx.org/blog/demo-day-demonstrations-and-props-used-my-g... (accessed January, 2024).
2. Campbell, D. J. “A Demo A Day II: Demonstrations and Props Used in My Environmental Chemistry Class.” ChemEd Xchange. https://www.chemedx.org/blog/demo-day-ii-demonstrations-and-props-used-m... (accessed January, 2024).
3. Campbell, D. J. “A Demo A Day III: Demonstrations and Props Used in My General Chemistry II Classes.” ChemEd Xchange. https://www.chemedx.org/blog/demo-day-iii-demonstrations-and-props-used-... (accessed January, 2024).
4. Ellis, A. B.; Geselbracht, M. J.; Johnson, B. J.; Lisensky, G. C.; Robinson, W. R. Teaching General Chemistry: A Materials Science Companion, 1st ed.; Oxford University Press: Oxford, 1993.
5. Callister, Jr., W. D.; Rethwisch, D. G. Materials Science and Engineering: An Introduction, 8th ed.; John Wiley and Sons: Hoboken, NJ, 2010.
6. Bradley University Chemistry Club. Demo Videos. https://sites.google.com/mail.bradley.edu/bradleychemdemos/demo-videos (accessed January, 2024).
7. Hook and Loop.com. Invention of VELCRO® Brand Hook and Loop. https://www.hookandloop.com/invention-velcro-brand#:~:text=The%20VELCRO%... (accessed January, 2024).
8. Campbell, D. J.; Querns, M. K. “Illustrating Poisson's Ratio with Paper Cutouts."  J. Chem. Educ., 2002, 79, 76.
9. Campbell, D.J.; Lojpur, B. ChemEd Xchange. "Microplastics, Liquid Nitrogen, and Iodine: Polystyrene vs. Starch Foam Packing Peanuts" (accessed January, 2024).
10. Campbell, D. J.; Hill, M. E. ChemEd Xchange. “3D Printed Structures of Carbon Allotropes.” https://www.chemedx.org/blog/3d-printed-structures-carbon-allotropes (accessed January, 2024).
11. Campbell, D. J.; Korte, K. E.; Xia, Y. “Fabrication and Analysis of Photonic Crystals.” J. Chem. Educ., 2007, 84,1824-1826.
12. Robinson, K. F.; Nguyen, P. N.; Applegren, N.; Campbell, D. J. “Illustrating Close-Packed and Graphite Structures with Paper Snowflake Cutouts.” The Chemical Educator, 2007, 12,163-166.
13. Williams College Thompson Physics Lab. “Atomic Trampoline.” https://physics.williams.edu/demonstrations/mechanics/atomic-trampoline/ (accessed January, 2024).
14. Campbell, D. ChemEd Xchange. “Tissue Paper Banners Connected to Chemistry.” https://www.chemedx.org/blog/tissue-paper-banners-connected-chemistry (accessed January, 2024).
15. Getz, W. A.; Wentzel, D. A.; Palmer, M. J.; Campbell, D. J. "Erasing the Glow in the Dark: Controlling the Trap and Release of Electrons in Phosphorescent Materials." J. Chem. Educ., 2018, 95, 295-299.
16. Berger, P.; Adelman, N. B.; Beckman, K. J.; Campbell, D. J.; Ellis, A. B.; Lisensky, G. C. "Preparation and Properties of an Aqueous Ferrofluid." J. Chem. Educ., 1999, 76, 943-948. 
17. Campbell, D. J.; Kuech, T. F.; Lisensky, G. C.; Lorenz, J. K.; Whittingham, M. S.; Ellis, A. B. "The Computer as a Materials Science Benchmark." J. Chem. Educ., 1998, 75, 297-312.  
18. Campbell, D. J.; Stancu, M.; Zhou, M. ChemEd Xchange. “Flash Rocks from Green Chemistry and LEGO Brick Perspectives.” https://www.chemedx.org/blog/flash-rocks-green-chemistry-and-lego-brick-... (accessed January, 2024).
19. Lippincott, K. A.; Rosengarten, E. A.; Sengupta, A.; Campbell, D. J. “Using Polymers and Pigments to Produce Laser Interference Rings.” J. Chem. Educ., 2019, 96, 2553-2559. 
20. MITK12Videos. Shape Memory Materials. https://www.youtube.com/watch?v=s62PL5vmfNw (accessed January, 2024).
21. Virginia Tech Department of Physics. “Happy/Sad Balls.” https://www.phys.vt.edu/outreach/projects-and-demos/demonstrations-wiki/... (accessed January, 2024).
22. Campbell, D. J.; Wright, E. A.; Dayisi, M. O.; Hoehn, M. R.; Kennedy, B. F.; Maxfield, B. M. “Classroom Illustrations of Acidic Air Pollution Using Nylon Fabric.” J. Chem. Educ., 2011, 88, 387-391.
23. Campbell, D. J.; Peterson, J. P.; Fitzjarrald, T. J. “Spectroscopy of Sound Transmission in Solid Samples.” J. Chem. Educ., 2014, 91, 1684-1688.
24. Campbell, D. J. ChemEd Xchange. “Polypropylene and the Cold Snap.” https://www.chemedx.org/blog/polypropylene-and-cold-snap (accessed January, 2024).