12.12.2015
Written By: Ralm Ricarte
Kamusta y’all,
Today’s experiment was an old favorite from last year: polymer swelling! First, I gave the students a quick review on the polymer concepts that they learned last week. Next, I illustrated the ubiquity of polymers in everyday life by using Drake’s “Started From the Bottom” video as an example (note: don’t worry, I only showed them the G-rated parts/1 millisecond of the video). Finally, we explored the physics of polymers by studying the swelling of the polymers in diapers. Essentially, the students measured the amount of tap water that a Huggies® Overnites Diaper could hold (hint: it’s a lot!). They then tried out different aqueous solutions (e.g., salt water, sugar water, soapy water) to see if that affected the absorbance of the diaper.
The students had a great time with the experiment. They were very surprised by the amount of water each diaper could absorb and greatly enjoyed ripping open the swollen diapers and playing with the polymer. Also, the students understood that the presence of solutes in the water would reduce the absorbance of the diapers.
Next year, I think this lesson may be improved by showing the students examples of non-Newtonian polymer solutions (e.g., poly(ethylene oxide) dissolved in water). This should expose the students to the concept that not only do liquids affect polymers, but also that polymers affect liquids.
Ciao,
Ralm Ricarte