Welcome to the Sound of Science. I’m Kate Powers – And I’m Mackenzie Thompson.
M: Kate, this week we have a burning question that comes to mind during the hot summer months. What is it about humidity that makes your hair so frizzy and curly?
K: As a curly hair girl, Pati, this question is close to my heart. And the basic answer to the question is simply: chemistry.
M: Chemistry? Are there chemical reactions between humid air and your hair?
K: Not necessarily chemical reactions but interactions happen between your hair and the water that hangs in humid air. Our hair is made of proteins that contain many sulphur atoms. Sulphur atoms are highly attracted to the hydrogen in the water molecules in the air. The water molecules stick to your individual hair proteins, spacing the strands out and creating frizz.
M: So, these tiny attractions between your hair protein and the water in the air are just temporary?
K: Exactly right! These tiny chemical interactions are responsible for all sorts of interesting phenomena in our world, my favorite being that these forces allow geckos to climb straight up a smooth wall.
M: Wow, I guess if you have enough tiny interactions happening at once they can add up to a lot of force!
K: Yeah, they can. I’m sure the hair care industry loves those tiny interactions. Take a stroll down the hair product aisle and keep an eye out for all the “frizz-free” products. What those products do is coat your hair in a smoothing agent, such as parabens or silicones that prevent those interactions from occurring. This can yield lovely smooth shiny straight hair. But ask any girl with very curly hair and she will tell you that she fervently avoids those types of ingredients! Not only do they prevent the interactions between your hair protein and water, they also prevent interaction between your hair protein and itself. And it’s those protein to protein interactions that form curls! Avoiding those products will allow your natural curls to look their best.
M: I didn’t know that there was so much science in our hair! If any of you have questions about science in your everyday life, shoot us an email at firstname.lastname@example.org. I'm Mackenzie Thompson.
K: And I’m Kate Power, and you’ve been listening to The Sound of Science on WNIJ.
M: Where you learn something new every day.