10.25.2018
Experiment leaders: Jake and Sagar
We started out our year working with Ms. Holly Siasoco’s science class at Marcy Open School with an investigation into the properties of the super-absorbent polymers used in diapers. Before starting the experiment, Jake gave a brief introduction and background about the types and uses of polymers. Then, the students broke up into groups of 2-3 (paired with one mentor each) and performed the experiment. In the experiment, students poured water with various concentrations of salt onto diapers until the diapers could no longer hold any water.
To begin, each group had to define a set of criteria which would determine when a diaper was “full.” Some groups decided to declare the diapers full if they were wet to the touch, while others would only consider the diapers “full” if they were dripping water. Then, they measured how much tap water diapers would hold. Students were impressed by the degree which the diapers swelled up!
Following this, Sagar asked the students whether they thought adding salt to the water would result in diapers absorbing less or more water. Students were divided on this question, so they investigated it for themselves, replicating their earlier test with several concentrations of salt water. They found that salt decreased the absorption capacity of diapers and each group plotted out their data on a poster:
At the end of the hour, students experimented with “insta-snow,” a powder of sodium polyacrylate, the same polymer in diapers. They were impressed with how much the powder expanded when water was added and how the seemingly solid insta-snow turned into a liquid when they sprinkled salt onto it. The students and mentors all had a great time—we can’t wait to come back in November!