Hair Science

What an awesome assignment! Seriously, how fun! I think maybe include the difference between color removers and color strippers are, and tie that in around bleach. I could go on forever and ever about these topics but I will try to find some related threads on here and links to other sites that summarize things well.

When it comes to semis and demis though, a lot of boxed 'semis' are actually demis. If it says it's a "semi" but requires a developer, it's technically a demi. Sometimes they market demis as only lasting X amount of washes, but a lot of demis never fade out. True semis are direct dyes that don't require peroxide. Demis only deposit color, you can't go lighter with a demi, and they typically use a vol of 10 or less. Permanents you can go lighter with as long as there isn't a demi or permanent already on the hair, and use a vol of 10 or more.

You could also touch lightly on the difference in developers. The higher the vol, the more it will lift the cuticle.

Here's a really good thread about coconut oil:
http://www.hairdyeforum.com/index.php?topic=3806.0

Argan oil is similar to coconut. Both are the only oils that can actually penetrate the hair. They both chelate damaging iron + copper chemical reactions that occur when using peroxide on the hair but I can't remember which one does more of which. One is more for copper and the other is more for iron, maybe someone else could clarify, or it may be in that thread I just linked

I know if you search on here there are threads about silicones and sulphates and reconstructors too

I'm pretty sure @puerkz has a cosmetic science background + she has linked before to some good articles from scientific journals and the like on here before

We actually have a couple of threads that talk about the science behind hair colouring/shampoos/etc.

How Hair Colour Works

Some of the Chemistry Behind Cosmetic Science

The links in those threads should help a lot!

Also, bonus thread:  Hair under the microscope.  It shows the different types of damage that can happen to the hair.

Thanks you too, this helps lots!
The only thing I haven't really found infos about is reconstructors. I'd like to find out at what point it is best to use reconstructors, or how how much damaged vs how much repaired hair should be that semis hold best. It's gonna be some sorta graph about that I think...