They Should’ve Called it Home Chemistry, Part 1: Ionic, Polar, and Nonpolar Cleaning Agents

This post is part of an ongoing series that delves into the chemistry behind cleaning and why it matters to you at home.

For a large portion of my life, I wasn’t entirely sure what happened at the dry cleaners. I just knew some of my clothes went to Mr. Gomez every few weeks and he returned them to me in mint condition. However, why particular clothes had the dreaded label “Dry Clean Only” and why other didn’t was knowledge that proved elusive. It wasn’t until I found myself staring at a withered and much loved top that had missed the cull to the cleaners and found itself on a spin cycle, that I though to even ask.

Dry cleaning is done for two reasons. Firstly, when a garment is made of a particular material that it cannot stand the roughness of the washing machine. I had a beautiful sequined number for NYE 2016 that was essentially a combination of sequins and dreams. After an evening involving lost keys and expensive Ubers (surge pricing is no joke), I found myself looking less than 100%. However, Mr. Gomez was able to wipe away the sins of the past, using what is called a “solvent”. In the cleaning world, solvents are the opposite of water based cleansers. Solvents are usually more toxic and odorous, not to mention expensive. Hence, you don’t find many people cleaning their entire house with isopropyl alcohol (a solvent).

Suddenly a light bulb went off over my head. While I had been cleaning my house for years, I took it for granted about why I used different types of cleansers for different things.

I decided to investigate further. Aside from classifying a cleaner as a solvent cleaner versus a water based cleaner, I discovered that these cleaners could be classified as ionic, polar, or nonpolar. I tried to break down the science as best as I could, but where needed, I included a linkback to the subreddit “Explain Like I’m 5”.

Ionic

Ionic chemicals are those at which their fundamental level are made of two oppositely charged particles. Hydrogen peroxide is a great example of an ionic chemical. Because of the unstable bond between the hydrogen and the peroxide, when we apply it to cuts it reacts to a certain enzyme in our bodies called catalase. The hydrogen peroxide oxidizes (that is it loses an oxygen molecule to the air) and breaks down the bacterial cell walls in the process (Live Science). Other examples of ionic chemicals include salt and baking soda.

“Ionic compounds share electrons until they have to come apart–in that case, the greedier one holds onto it tighter and the more complacent one gives it up. That’s why the charges are on Na+ and Cl-. My boyfriend LOVES fried chicken and I don’t care too much for them. Yes, we’ll get a bucket of KFC and share it but you know if we ever have to split the bucket, he’ll definitely have more pieces on his plate than mine because he’s less willing to give it up (more electronegative) while I wouldn’t mind giving it up (less electronegative).
Molecular compounds, however, share electrons and love them the same amount. Therefore, neither likes it more strongly enough to be able to take the electron away from the other–that means they’re constantly holding onto it together so that is why they don’t come apart in water. “

https://www.reddit.com/r/explainlikeimfive/comments/1glul1/eli5_can_anyone_explain_molecular_and_ionic

Polar

Polar chemicals have some charge and are thus partially ionic, but for our purposes we are classifying them as a subset here. Polar chemicals generally are soluble in water. However, polar and non polar chemicals do not mix. This is where the saying “like oil and water” comes from. Oil is nonpolar. Other examples of polar chemicals include alcohol and vinegar.

A polar molecule has a positive charge on one end and a negative charge on the opposite end. Because of this, polar molecules align end to end like magnets. The charge difference is caused by one atom of the molecule being “stronger” and therefore better at pulling electrons towards it.

https://www.reddit.com/r/explainlikeimfive/comments/jdgm3/eli5_the_difference_between_polar_and_nonpolar/

Nonpolar

A nonpolar chemical is not charged at all. Common nonpolar cleaners include furniture oil, dry cleaning solvents, or floor waxes. Nonpolar chemicals are great at cleaning each other. My beautiful dress that was covered in body sweat and oil as well as some grease from late night fast food was the perfect companion to the solvent that Pete would later use.

But why does this matter?

I am a big proponent of teaching the “why” to children. Often times, as adults we just continue to do a thing, because that’s what we were told to do. Often times, with a little more introspection, a bit more knowledge will help us create a more efficient way to complete a task. Hence, I am passing this knowledge onto you!

Stay tuned for the next post in Home Chemistry. Part 2 will do a deep dive into soap and detergent.