Task 1:
To understand the production of aerogels, we want to start with Samuel Kistler’s bet and try to produce hydrogels ourselves and then dry them.
We recommend trying several different gels, as they behave differently. However, you can also choose one recipe.
You can read which ingredients you need and how to make the gels by clicking on the following sections. The list of ingredients or the instructions will then unfold.
Drying Hydrogels
Experimental Procedure:
Take the gels from Experiment 1 and try to dry them without them shrinking. This can be done either in the air (takes several days) or in the oven. Perhaps you can think of other possibilities. We dried gels and fruit in the oven for 4 hours at 70°C convection or 9 hours at 50°C convection on a baking sheet lined with parchment paper.
Important: First, think about how you want to evaluate the experiment (see “Evaluation” section below). You should measure your hydrogels before and after drying, and ideally also photograph them.
Note:
In addition to the “slimy” gels, you can also use fruit, which also binds a lot of moisture. For example, like this:
- Peel an apple or a piece of cucumber and cut out a cube-shaped piece of approx. 2x2x2 cm.
- If you want to use grapes or blueberries, you can use them whole.
- You should peel bananas and cut them into uniform slices of approx. 2 cm thickness.
Evaluation:
- Describe: How do your gels behave during drying?
- Measure how length, width, height, and weight change over time. From length, width, and height, you can also calculate the volume and see how it changes.
- Present your results in a logbook. You can download our sample logbook for this purpose.
- Look at the results. Did you succeed in avoiding shrinkage?
The experiment instructions are also available here for printing.
Task 2:
How do your gels behave during drying? Measure how length, width, height, and weight change over time. From length, width, and height, you can also calculate the volume and see how it changes. Share your observations with others in the Community.