Extracting the blue dye in jeans

In this video, I decided to try and extract indigo dye from an old pair of jeans. I managed to find a decent way to do it, and in the future, I'll try to scale up the process and do it on a full pair.

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[schmitty]

Seeing your trial and error is my favorite part of your videos. So many other science type channels just tell you what is but you really go into it and sometimes get unexpected results. BY FAR my favorite chemistry channel.

[KainYusanagi]

NileRed, regarding Sodium Hydrosulfite (aka Sodium Dithionite), which is an alkali salt itself; from Wikipedia: "It is used as such in some industrial dyeing processes, primarily those involving sulfur dyes and vat dyes, where an otherwise water-insoluble dye can be reduced into a water-soluble alkali metal salt (e.g. indigo dye)" So basically the indigo was being kept water-soluble because it was an alkali metal salt. Adding the acid neutralized the alkali and separated out the indigo dye which then was no longer water-soluble.

[DrInorganick]

Okay, a couple of things. I've been working with indigo for a few years during my PhD, so there are a few things you could try. For one, as you alluded to, indigo's one characteristic property is its abysmal solubility. Good for a dye, bad for a reagent. Older german papers talk about its solubility in either boiling chloroform, or in neat sulfuric acid, but we have typically used it as a suspension in DMF at around ~260 mg in 40 mL. By itself, it is not very soluble, but a lot of derivatives are considerably more soluble because they typically have less inter/intramolecular hydrogen bonding. Salts in particular have higher solubility (probably why you werent getting anything precipitating before adding acid - indigo is fairly acidic because the N-anion is stabilised), and N-alkyl derivatives are fairly well-behaved (i.e. di-boc indigo will dissolve in hexane). Because of the hydrogen bonding and electronics aspects, a lot of derivatives have different colours. N-acetyl indigos are typically red, mono-N-alkyl derivatives are usually blue, and di-alkyl derivatives are green. The really interesting stuff comes from other modifications of the core ring structure, which is what I've been working on. If you're interested, get in contact and we can talk more about it.

[art_and_sh.t]

Me, knowing absolutely nothing about chemistry: hehe color

[littlebacchus]

Need to see this go full and extract all the indigo. I'd shred the fabric smaller first though.

[augustg]

I love chemistry and am a horrible test taker. I was getting a 54 in grade 11 chemistry and my teacher saw I wasn’t stupid and asked what the problem was. I told her I loved the class and understood her, just had test anxiety. I showed her one of your videos and said “this is why I took chemistry. I love it and I understand it” she ended up loving your channel and having good conversations with me over them. She passed me with a 70 after the exam. Thanks for your help there 😂. I won’t be continuing chemistry next year but I will be continue watching your videos

[miamama]

"I need a solvent that is cheap and nontoxic as possible"

*Uses DCM*

[zell]

My son is 6 and loves your demonstrations! I caught him in the driveway wearing goggles playing in a puddle. I asked him what he was doing.. Chemistry Dad, Chemistry, he said. Keep up the great work 👍🤘

[egretwhite]

Heh, the idea of using pH-paper in a cup of dye seems problematic.

[codyv]

I love this channel because you do a really good job of talking and explaining your methods, and your production quality has increased tremendously over time. I think I've learned more about chemistry by watching your videos than I ever did in high school. Keep this up and you'll have a golden play button in no-time :)

[taiwanluthiers]

What if you take the leftover denim, and break it down and make moonshine out of it?

[Fvneral_moon]

Next video idea: "Extracting cocaine from a vintage Coca-Cola bottle"

[User_]

This video feels a lot more like "practical chemistry" than "educational chemistry", love it.

[moechano]

"Didn't fit me anymore"
Nilered becoming thic c

[emmamattson]

I am clueless about all of this stuff, BUT I love watching and listening to your videos. I feel like I'm in a science class I missed out on.

[TheLeftHandOfDankness]

Oh my god i love the way he keeps all the scenes in proportion to each other and throws off the sense of scale.

[boba_fairy]

Even though I find all of his videos really interesting, my favorite parts is near the beginning or end when he includes just pictures of him having fun. By far my favorite part about learning applied science and chem is actually enjoying what you're doing. For someone whose main job is probably spending laborious hours on conducting these kinds of interesting experiments, it feels really good seeing that they enjoy what they do :)

[samuelpell]

The true mark of a great YouTube channel is an audible promotion. Glad to hear that you made it to stardom

[lovehawks]

Strictly speaking from a geological background, but strong bases are used in particle size analysis for clays and silts. What happens is that the base prevents the clay grains from clumping together by interrupting the static charge that builds up on the surfaces of the grains. Perhaps, a similar process is happening with the indigo.

[Somedude]

Honestly; I find these videos super fascinating when i’m awake, and relaxing when I’m tired! I can easily fall asleep listening to your voice