# Water Permeability

To conduct this experiment, I used a bioplastic bag constructed from Ag12, and the process was described in the post "Heat Joining Bioplastic". The bag was grasped by soldering "helping hands", which are like alligator clips on a metal rod, though other instruments would probably serve this purpose better. Then, I injected 10 mL of water into the bag with the help of a syringe.

My setup:

![](/files/Z8bQH62U93KeUqOe6dJ1)

The results:

The bag could hold water for a few hours (approx. 4) before water ended up on the newspaper. I couldn't tell if this was because water was actually traveling through the bioplastic, or if I joined the bioplastic poorly, but either way, it seems like I will redo the test.

An interesting thing I found is that the part of the bag that was holding the bioplastic actually started to biodegrade (or something else) a bit because it shrank and became rigid and hard, while the bioplastic that was not directly touching water didn't. By biodegrade, I mean that the glycerol started to leach out with the help of the water (I think). I think this for two reasons: (1 a sticky substance was found in the water that came through the bioplastic and (2 glycerol acts as a plasticizer which keeps things flexible, and the part touching the water lost its flexibility.

Before photo:

![](/files/HMPe86lMG7H6nLuPAGRo)

After photo:

![](/files/mvamc6UevEr0LFHjvwrL)

Testing photo:

![](/files/5Eyc3JQpI1DL5stOh8tq)

Notice the meniscus there. A meniscus forms when the material has a charge because water is polar and wants to stick to stuff that has a charge. So, this means the bioplastic has a charge.


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