100 Nano-Stories: Debunking DMBZ & PPDA!
Episode #23: Explaining Polyimide Chemicals!
Preface →✨
All right, readers! We have now broken down the fundamentals of what exactly is polyimide! Now we can move on to breaking down some of the chemicals used in polyimides!
But wait, Carlos! I don’t understand what you are talking about, so can you please describe the meaning of all this?
In the previous article of mine, I talked about the chemical structure of polyimide, breaking each section of the chemistry, and what it means to have the polyimide in our aerogel in the first place! But it never hurts to check it out and grasp the content before reading this one! 😊
But enough writing, let’s jump into the world of chemicals, and see what we can break down & simplify! Or as Dr. Nefario would say. . .
Chemistry Lines & Symbols → 👨🏽🔬
If you noticed carefully in my last post, some lines went across the basic chemical structure of polyimide.
So what do the dotted lines mean, Carlos? Also, what do the straight lines in the chemical structure mean?
Well, the straight lines in a chemical bond mean that the bond between two atoms is in the drawing plane of the diagram.
The dotted line means an intramolecular bond/hydrogen bond. What this means is that there is an attractive force between molecules, so there is a distance between the two molecules.
In a straight line, the bonds are directly connected because of the sharing of electrons. But in an intramolecular bond, it’s because of polar groups. Similar to the polar groups that lie on the surface of the hydrophilic silica aerogel, there are poles (north & south) in the molecule, which allow for these intramolecular bonds to happen in the first place.
Woah, that’s crazy! Thanks for clearing that up, Carlos!
No problem! Now, the last thing before we continue with the actual polyimide aerogels is in the name of the chemicals themselves! Remember our good friends “2,2ʹ-dimethylbenzidine (DMBZ)” and “p-phenylenediamine (PPDA)”? Do you know what the apostrophe in “DMBZ” means?
The apostrophe in 2,2ʹ-dimethylbenzidine (DMBZ) specifically, means that we have benzidine with a dimethyl group on the second atom of the second carbon ring of our molecular structure! 1 of (’) means that this has a secondary structure, so this is why we end up with 2,2ʹ-dimethylbenzidine (DMBZ)!
Closing Thoughts → 💭
Okay, Carlos! Thank you for the explanation! So does this conclude our lesson of organic chemistry to proceed with the actual polyimide aerogels?
Yes, reader! Tomorrow, we will continue with actually describing the process of supercritical drying & the remaining chemicals of polyimide aerogels! But on the bright side, now you know a bit more to kick a** in your chemistry class! 😉
Vocabulary → 📓
Organic Compounds → 1 or more carbon atoms are connected with other elements, mostly either hydrogen, oxygen, or nitrogen.
Intramolecular Bond/Hydrogen Bond → There is an attractive force between molecules, so there is a distance between the two molecules.
Polymer Aerogel → A material made up of monomers or macromolecules as the network of the aerogel.
Polyimides → A type of plastic with high-performing mechanical properties such as resistance to high-temperature and corrosion (determination of a metal over a period of time).
Bonus Resources → 💻
Previous “100 Nano-Stories” → 🔖
© 2021 by Carlos Manuel Jarquin Sanchez. All Rights Reserved.
