Science Buddies: "Ask an Expert"

So my science fair projects due in 2 days..and I JUST bought my materials. What I'm gonna do is see which brand is the most water repellent. I know that Dimethicone is one of the main ingredients that keeps it water repellent. But I don't exactly know how to test it. Or fine my variables or any of that... any help would be appreciated? [:

Hi,

I apologize for the delay in responding to your inquiry. I hope the following information will help you.

Here is an idea for a method for testing mascara:

http://www.easy-kids-science-experiment ... jects.html

To improve the experiment, I would recommend measuring the amount of mascara that is applied to paper, and devising some way to measure the amount of color that leaches from the paper sample when it is soaked in water. One suggestion would be to soak the sample in water for a minute of two and evaluate the amount of color compared to water in the sample. If the mascara is completely waterproof, the water will remain clear.

Dimethicone is a silica based compound that contains lots of carbons and hydrogen atoms, which makes it hydrophobic or water repellent. Here is a website that includes the structure:
y
http://www.newdruginfo.com/pharmacopeia ... m26510.htm

Here is basic information on the composition of mascara. What is the composition of the samples you are testing?

http://www.eye-make-up-tips.com/eye-cos ... ients.aspx


I hope this helps.

Donna Hardy