Denim washing involves the use of basic chemicals such as anti-back staining agents, detergent, soda ash, enzyme, stone, hydrogen peroxide, acetic acid, potassium permanganate, bleach, Meta, hypo, and softener. The chemical dyeing process for denim fabric involves synthetic dyes created through a series of chemical reactions that bond the color. Indigo tinctoria and I. suifruticosa are the most common indigo dyes, which were once a precious commodity due to their small amount.
The amylase enzyme is the most popular method of removing starch from denim garments, breaking down long starch molecular chains into smaller molecules. There are several chemical treatments used in the denim industry to remove impurities and coloring and produce appropriate finishing. Enzyme washing or “bio stoning” is a textile finishing process where enzymes are applied to denim or fabric to achieve a special look, such as stone washing, a softer feel, or a vintage look.
Sulphur-based dyes, sodium hydroxide, hydrosulphate, and formaldehyde are chemicals typically used in denim manufacturing processes. In postmanufacturing finishing, jeans are chemically washed to achieve a faded look. Chemicals used in producing synthetic indigo pigment include aniline, sulfur, sodium hydroxide, hydrosulfate, and others.
Different chemicals, such as detergents, Na2CO3, enzymes, and oxidative substances, can be used to achieve these effects. Following the ban on potassium permanganate (PP), two chemicals often cited as potential health risks are potassium permanganate and sodium metabisulphite.
In addition to these chemicals, denim fabric is made of a special weaving of dyeing and undyed yarn, with the warp yarn being dyed with indigo, a special dyestuff.
📹 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 …
What chemicals soften denim?
This text describes a solution of silicone polymer for the creation of a slippery, soft, and non-fatty hand-feel on fibers, including both natural and synthetic ones. Additionally, it outlines the development of a cationic, anti-static softener derived from a flake form of fatty acid.
How do you remove formaldehyde from new jeans?
To remove the chemical smell from jeans, wash them with a mixture of baking soda and vinegar in cold water or soak them overnight in a solution of water and white vinegar. These methods neutralize and eliminate chemical odors without harming the fabric. Denim jeans often have a sharp chemical smell, primarily due to formaldehyde, a preservative used in the textile industry. To find the best fitting jeans, visit Tapered Menswear and explore proven odour removal techniques.
What is used to dye jeans nowadays?
Denim makers can dye with various methods, including 100 indigo, a mix of indigo and sulfur, and 100 sulfur, which is used for black and color denim. In the 1970s, sulfur was introduced to cut costs and is now used to add tops and bottoms to indigo-dyed yarn. However, the cast can be controlled without sulfur by changing the chemistry of the dye bath. 100 indigo dyeing produces a characteristic red cast, similar to the iconic denim made by Cone for Levi’s in the 1950s and 60s.
What is 100% denim made of?
Authentic denim is made with 100% cotton, providing a durable and unique texture. It molds to the body with each wear, making jeans uniquely yours. While cotton-only jeans are preferred, some stretch options offer extra comfort. Maintaining denim is essential as it ages and breaks in well, becoming more comfortable as it gets older. True denim should be worn in to mold to the wearer’s form, become softer, and cultivate its own personality. It is very low maintenance.
Can you wash chemicals out of jeans?
To prevent pesticide residues from transferring to other clothing, it is essential to keep contaminated clothing separate from other items and use a disposable plastic bag instead of cloth bags or laundry baskets. Wear rubber gloves when handling contaminated garments and use prewash soil and stain remover or heavy-duty liquid detergent for stains. Pre-rinse contaminated clothing by hosing down outdoors, soaking in a separate tub or pail, or agitating in the washing machine. Wash contaminated clothing separately from the family wash, as pesticide residues can transfer to other clothing when laundered together.
Wash only a few contaminated garments at a time, and use as hot a water temperature as possible. Set the washer water level for extra large or large loads, and use regular cycle settings and normal wash speed settings. A double rinse is recommended. Use the recommended amount of heavy-duty liquid laundry detergent, as it is more effective in removing oil-based pesticide formulations. Laundry additives like chlorine bleach or ammonia do not improve the removal of pesticide residues.
Multiple washings are needed if clothing was worn when using highly toxic or concentrated pesticides, while clothing worn while using low-toxicity products can be laundered effectively in one machine washing. Check the pesticide label for toxicity levels and discard clothing heavily soiled with full-strength or concentrated liquid pesticides. Line dry garments to prevent residues from collecting in the dryer. Remove any leftover pesticides from the washer by running an “empty load” through the complete cycle. Choose phosphate (powdered) or heavy-duty liquid detergent for better residue removal.
Are jeans still dyed with indigo?
Indigo, a green plant, is responsible for giving denim its deep blue color. The tradition of indigo dyeing originated in Japan in the 17th century and was used by Samurai. Nowadays, most jeans are dyed with synthetic indigo due to cost and time efficiency. However, the natural indigo dyeing process is still practiced in Tokushima, Japan, home to one of the country’s most artisanal factories.
The footage showcases the application of old techniques and highlights the advantages of natural indigo dyeing. Natural indigo prevents jeans from becoming smelly and dirty, and the latest Pablo Stone Blue is made from naturally dyed denim cloth from the Nihon Menpu denim mill in Okayama. The denim dyed with natural indigo has a deeper blue hue and maintains its color for longer as the dye penetrates the cotton fiber.
However, natural indigo dyeing is more time-consuming and more expensive than synthetically dyed jeans. The result is a pair of jeans that are resistant to dirt, odour, and will age more distinctively. The Pablo Stone Blue is made in a limited run of 50 pairs, finished with a tonal, light blue selvedge, and features a straight leg and button fly. As part of their 9-year anniversary celebration, this pair of jeans is an investment that will be with you for a long time.
Is there formaldehyde in denim?
Formaldehyde is a toxic chemical commonly used in the manufacturing process of jeans to prevent mold, bacteria, and mildew damage during storage and shipping. It is also used to create wrinkle-free and stain-resistant features. While not all manufacturers use harmful chemicals during production, it is important to wash new jeans before wearing them. If you have denim with a strange chemical smell, you can get rid of it by using baking soda. To absorb the smell, soak jeans in cold water with baking soda dissolved in it before washing. This natural method is a reliable and safe way to combat chemical smells in your clothes.
Is denim stronger than cotton?
Denim, a heavier fabric than regular cotton, is known for its strength and longevity due to its higher density and thickness. Its increased thread count makes it durable, able to withstand harsh use and frequent washing. Heavy-duty denim is used in workwear, jackets, and upholstery. The type and quality of yarn used in denim production, such as ring-spun and combed cotton, significantly impact its strength and durability.
What is high quality denim made of?
Denim is a durable cotton fabric with a distinctive diagonal twill pattern, created by the weft yarn passing under two warp yarns. The white yarn derived from the cotton plant must undergo a dyeing process to impart a distinct coloration.
What are the ingredients in denim?
Traditional denim yarn is made from cotton fibers that are cleaned and combed into long, cohesive lengths. These fibers are spun into yarn using an industrial machine, and various treatments are used to alter the appearance of denim products. Some yarns may substitute an elastic component like spandex for up to 3 of the cotton, resulting in a woven form called’stretch denim’ with up to 15 elasticity. Denim was originally dyed with indigo dye extracted from plants, often from the genus Indigofera.
In South Asia, the plant was called “true indigo” or “natural indigo”. In Europe, the use of Isatis tinctoria, or woad, dates back to the 8th century BC. Today, most denim is dyed with synthetic indigo dye. The yarn undergoes a repeated sequence of dipping and oxidation to achieve the desired color.
What is denim dyed with?
The dyeing of denim is achieved through the immersion of the yarn in a solution containing the requisite dye. The warp yarns are dyed blue on the front and white on the back, while the weft yarns are left undyed or bleached. Industrial-scale indigo dyeing entails the bundling of yarns into ropes or sheets and their passage through continuous dyeing ranges, designated as rope dyeing and slasher dyeing, respectively.
📹 Denim Washing Chemical Name
I love this website 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 perusal your articles than I ever did in high school. Keep this up and you’ll have a golden play button in no-time 🙂
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.
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.
Even though I find all of his articles 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 🙂
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 articles and said “this is why I took chemistry. I love it and I understand it” she ended up loving your website 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 perusal your articles
Hey NileRed, I have seen your articles pop up in my recommended feed a lot and just recently clicked onto one of your articles for the first time. Since then I have watched quite a bit of your articles, and your articles are really fascinating. I know next to nothing about chemistry but yet you somehow make it interesting. Never thought perusal a article about making soap would be so entertaining. I just want to say that your content here on YouTube is amazing and you should keep it up! 😀
Reason for soluble dye in base: With this particular arrangement, the two neighboring keytone-amine groups provide hydrogen bonding sites, but not quite enough to overcome the hydrophobic parts of the molecule. However, in a strong hydroxide base, the negative charged hydroxide is just the right size to squeeze inbetween the amine and keytone groups on each side and strongly lock in place through hydrogen bonding. This is similar to ligand formation with transition metal cations. It now acts as a complex with a net – charge the -OH is providing, making it much more soluble in H2O. The size of the -OH and distance between R-NH-R and =O groups are just right to create this effect. The indigo should extract directly from the jeans somewhat with a hot -OH solution, but this is just in theory…as the other dissolved species from the iron-out may act as a “soap” to help drag the indigo into solution through intermolecular interactions. I would think this should be minimal, but I’d have to study it further in detail. The -OH creating a ligand-like complex, though, im quite confident is mainly responsible for the unexpected solubility.
I used to work in an environmental laboratory as a lab tech, we used methalyne chloride(DCM), acetone, and ethyl ether to extract compounds from water and soil samples, be careful using the DCM, I had a nozzle from the storage tank malfunction and spray me with the stuff head to toe, super uncomfortable and it soaks through latex gloves
The reason it was soluble in basic conditions and not acidic is because the amine protons are actually fairly acidic (due to the conjugation). In basic conditions they are deprotonated and negatively charged, giving you your water solubility. In acidic conditions they are neutral and thus very hydrophobic.
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.
Maybe the extraction of indigo would be a little more efficient if you laid the denim pieces flat in some kind of pan and let the solution heat up in this, because then all the surface area of the denim would be covered by the solution and you may be able to receive more indigo from just one extraction run.
If you ask a textile artist, they will tell you that the precursor molecules that form indigo need to bond with oxygen before it turns blue. What you appear to have in your batch at 5:22 are these oxygen-starved molecular chains. But I’ve never had someone try to remove indigo with a drain cleaner. Haha.
Great article @nilered. I do educational living history demonstrations with woad (the native European plant source for the same indigo dye used in Western Europe from the Bronze Age to Viking Age) and we use the results in historic weaving and costumes. We also use hydrosulfite, as the ancient method (ammonia from urine fermentation as the reducing agent) is too disgusting for public demos. Some further ideas for related projects; trace evidence from Anglo Saxon and Viking textiles have traces of a purple dye from lichens, thought to be the “cudbear” dye orcerin. From what I understand this dye works similarly, with a reduction to a soluble state, then oxidation in the fabric. I wonder if you could get hold of some or synthesise it? Another more famous dye is the historically exquisitely expensive Tyrian purple worn by Roman and Byzantine Emperors which was extracted from now very rare Murex sea snails. The dye is near impossible to get hold of now owing to its unsustainability. Although Tyrian purple is 6-6’-dibromoindigo it is not just a simple bromination, but I did find a paper describing a reportedly “simple, safe and efficient” way of synthesising it (Wolk, 2010). Seeing this famous ancient dye being synthesised would be fascinating!
I tried this with the idea of selling the indigo on the internet for profit. I bought a pair of diesel jeans that were very light blue. I bought all the chemicals I also needed all the glass ware and supplies The reaction took me several hours to get right. In total I got less then a gram of indigo and to break even I have to sell it for $3500 a gram. Maybe if I scale down the reaction or buy higher quality designer jeans it will be more profitable or just profitable. I’m also working on making diesel fuel from calcium carbonate from gummy vitamins and hydrogen peroxide grown by microbes that will be cheaper then what you pay at the pumps. Should work right? Byproducts are clean oxygen and calcium for strong bones! At least this is more viable then making plastic from air like that company claims they do. Atmospheric CO2 and water into plastic that doesn’t take much energy to go totally backwards.
You just demonstrated subtractive dye for jeans. The patterns in your final sample are attractive and could be extended to creating a ‘tie dye’ look in jeans. Fabric artists would be very interested in decorating indigo dyed garments by protecting some of the fabric with tightly wrapped string, or even wax and then subtracting indigo. Congratulations.
What I think, not 100% sure. So, NaHSO3 is an acidic salt, hence its H+ ions given in water dissociation. I’m pretty sure that the blue color came from the formation of indigo carmine (disodium 5,5′-indigodisulfonoate). Indigo reacted with SO3(2-) ions in the solution to form 5,5′- indigosulfonic anions(1-) wich on their side reacted with the Na cations(1+)(from the NaOH)to form the indigo carmine; the carmine is blue and soluble in water. Adding the HCl acid reacted with it. The Na cations reacted with the Cl(1-) anions to form NaCl and the H(1+)(from HCl), which replaced the sodium ones, just created 5,5′-indigosulfonic acid which later due to the excess of H(1+) ions from the NaHSO4 just dissociated to indigo(which precipitated) and 2 molecules of H2SO3. But I’m not sure like I said 🙂
I did a quick chemicalize.com property search on “(2E)-2-(3-Oxo-1,3-dihydro-2H-indol-2-ylidene)-1,2-dihydro-3H-indol-3-one” (only becasue “indigo” didnt work). When I did, I took a look at the pKa and solubility calculations and am starting to wonder if you need anything more than just H2O, NaOH, and HCl because it looks like you can extract using 0.1 N NaOH (aq.) to extract the indigo, remove the jean material and then simply add some acid until a pH of around 5 is achieved, filter the precipitate, then wash with water to remove any residual salts. Thoughts all? @NileRed
Hello Nile Red i love your channal as much as the chemistry but i have a question i cannot seem to really find a solution for. While schooling how did you go about studying higher level chemistry i am struggling adapting my styles to such a diverse and complex field, can you give me some inside tips or tricks for all the students out thier?
You were missing something reasonably obvious. The iron out contains sodium carbonate and hence the pH will have initialy means it will have been around 9/10. A typical amide has a pKa of around 18, which means you’d need sodium hydroxide (and of course anything more basic) to deprotonate it. Indigo however, will have a much lower pKa, so much lower in fact one of the amides is fairly easily able to exist in it’s iminol form. This is because the deprotonated nitrogen can delocalise it’s negative charge across both oxygens and one of the aromatic rings. And hence the much greater anion stability and lower pKa. So clearly based upon that sodium carbonate was easily able to deprotonate the indigo and produce a water soluble sodium salt which you then destroyed by adding the HCl.
First, I love your articles and have watched all of them. Second, I really want to become a professional science YouTube where I do (and explain) interesting science in articles. I am running into a number of problems in my effort to do this. The first problem is that it takes a lot of resources to make science articles, and I lack resources, and second I don’t know how to get good at article production. Do you have any advice? I am typing this from my YouTube website account on the off chance that it would be useful to see what I have posted so far.
I’m fascinated by chemistry, but don’t know much more than the basics about it. I do have a recommendation for this, though: the washed scraps of denim from your second extraction clearly have dark spots where the fabric folded and didn’t move around much, so the indigo didn’t have a chance to dissolve and escape from the fabric. If you ever plan to do this on a larger scale, like with a whole pair of jeans, I’d recommend either using some method that lets you physically move the solution to shake it and the fabric around to shake loose the dye (although I can’t think of a way to do it that wouldn’t require a huge dissolving solution and way too much of the chemicals), or cut the fabric into far smaller pieces (or even just shred it) so that they can move around more freely. Also, you consistently referred to the reducing agent as dithionite in the first article; is that another term for hydrosulfite?
it probably formed a colloid with particles of indigo less than 10 microns wide which are too small and too dispersed to be filtered by a coffee filter. I’m no chemist so I’m not sure how fine of particles you can filter out with your fancy equipment but I think it would be worth a try in addition I would be interested to see about reusability of the chemicals used in the process and see if it would be practical to extract a large amount without having to clear the shelves of drain cleaner and rust out
A couple of extraction ideas: You can try using a Soxhlet Extractor with ethyl acetate to always be washing with a clean solvent. If you stick with the solvent that you ended the article with then you should take a tube of PVC or something (after you make sure it is chemically compatible), and loosely fill it with the denim. Pour the solvent in the top, and let it drain out of the bottom. This will ensure that the solvent is getting more and more concentrated as it passes through the denim. When you think the denim that is at the top is fully extracted then you can push more fresh denim into the bottom and squeeze the denim at the top out of the pipe. Source: I am helping design a pilot scale counter-current extractor. If anybody has any questions about this process (that is not directly related to my job), feel free to ask.
I’m so glad that I found your website! You’re articles are so fascinating and fun to watch and I really learn a lot. I think you explain things very cleanly and it’s really easy to understand. And I also have a huuuugeeee amount of respect for you for putting in “fails”! Its a huge part of learning and I really appriciate it.Lots of love! Keep up the amazing work!
Take a look into liquid-liquid extraction. Some indigo salts probably formed with some sodium from the iron out and caused the indigo to be much more soluble in water. Then when you added the HCl it pulled the sodium back off of the indigo, causing it to crash out. Its commonly done with benzoic acid and phenanthrene in lab courses in college.
Explanation to 8:45: Indigo’s molecule is more or less only slightly positively polar that water alone is not enough to dissolve it. NaOH combined with water was good to dissolve it since the polarity is constructive, when you poured acid, you threw the polarity out of bond, and the Indigo precipitated as a result.
I’m not anything close to a chemist but I think that the blue form of indigo was staying in solution kind of like sometimes if you are careful you can have water below it’s freezing point and it freezes instantly when you disturb it. The acid disturbed the indigo that was in solution and it started to fall out
The test tube you used at the end for the Hyperbolic test may I use that Audio as a Foley sample? I just love the sound it gives off, also please forgive any grammatical errors I am typing single handed and with a terrible cold. The sound is almost like my favorite old SFX from the WB and HB days best onomatopoeia I can write it out in is “Booomwadoom!” Always had to do with high energy but both me and my father have no clue what the Foley artist used, and we know that the Iconic tornado sound of Taz was a hand crank generator if I recall correctly.
An interesting article idea would be the synthesis of 6,6-dibromoindigo aka tyrian purple. Could it be made from some of the Indigo you have made/collected? Apparently it was the dye of emporers. I see various attempts tekhelet.com/pdf/0981.pdf but they call for some chemicals I am not familiar with.
Nile Red! In your article I saw that beaker with the dye inside it, and I saw a little bit of light blue swirled around like tie dye. I was pretty sure it had something to do with the chemicals you were using. Guess what? I also have my own tie dye kit in my own house. I also love science. I want it to be my career. But I also love animals, so I’m thinking I would do something not totally about science but not totally about animals. Anyway, when I grow up, I want to be a veterinarian. Love, Agnes (5 years old)
This got me wondering what exactly happens when you put sodium hypochlorite bleach on jeans. It definitely removes or destroys the indigo, but I don’t know what the chemistry is. BTW, the Royal Institution posted a article this morning on the Belousov-Zhabotinsky reaction and at first I thought it was a new article from you.
I can’t be 100% certain, but perhaps the carbonyl on the indigo is susceptible to being converted into an acetal/hemiacetal equilibrium in basic conditions? That could potentially affect solubility. Either way, the reason has to be due to the base changing something about the structure is a way that it kind of mimics the way the acids and bases change solubility of compounds with salts or whatever.
This stuff goes way over my head because chemistry classes in high school were just theoretical. Last time I had chemistry lessons was in ’96-’97. WE NEVER USED A LAB. EVER. Not even a telly with a article showing a practical example of the subject matter. I still did good in the national test in chemistry to get the high school diploma, but never got to see any experiments performed aside from taking a blood sample to find out the type.
I’m too lazy to read through all the comments, so I apologize if this has been said. Regarding why the acid knocked the indigo out of solution (I believe that question was posed) I just wanted to remind those old and/unfortunate enough to remember: Acid-Washed Jeans… That hideous 80s fave probably contains the answer. (Liberal arts grad here; don’t know much about the actual chemistry).
I think you should wring out the bleached fabric before sending it to another extraction step. Any liquid you can get out of it with extracted indigo will increase your yield.Also, any indigo that deposits on your glassware or gloves can be recovered using another batch of the reducing solution. Perhaps the indigo formed in the alkaline solution under intense stirring is just particles too fine to settle or filter out, and with a surface charge that prevents them from clumping. Acidifying the solution allows them to clump up so they can settle and are caught in the filter. Could you oxxygenate the solution with hydrogen peroxide? It should not take much. Or perhaps you could find some form of stirring which incorporates as much air but stirs the liquid less. Maybe acidify even before you start aerating?
Nile red, ialm your biggest fan, i request you that you do an demo of creating hair promoing medicine in this website…. please show us if its possible for us to create a DIY super hair tonic that anyone can do at home. I request you to show that by creating a solution of DMSO, Methylsulfonylmethane(MSM),Magnesium ascorbylphosphate( MAP), EGCG, Dihydroquercetin, BioChaninA and Acetyltetrapeptide-3… These are the most effective hair growth ingredients that i have researched, but donot know to go about making a solution of all these into one… DMSO is a common carrier vehicle and conditioner and all other ingredients are hair promoters…… i would eally appreciate of you and whoever interested to reply to me with ideas …. Thank you all so much
Now usually I don’t do this but uh Go head’ on and break ’em off wit a lil’ preview of the remix No I’m not tryin’ to be rude, But hey pretty girl I’m feelin’ you The way you do the things you do Remind me of my Lexus coup That’s why I’m all up in yo grill Tryna get you to a hotel You must be a football coach The way you got me playin’ the field So baby gimme that toot toot Lemme give you that beep beep Runnin’ her hands through my ‘fro Bouncin’ on 24’s While they sayin on the radio It’s the remix to ignition Hot and fresh out the kitchen Mama rollin’ that body Got every man in here wishin’ Sippin’ on coke and rum I’m like so what I’m drunk It’s the freakin’ weekend baby I’m about to have me some fun Bounce Bounce Bounce Bounce Bounce Bounce Bounce Bounce Bounce Bounce Now it’s like murder she wrote Once I get you out them clothes Privacy is on the door But still they can hear you screamin’ more Girl I’m feelin’ what you feelin’ No more hopin’ and wishin’ I’m bout to take my key and Stick it in the ignition So gimme that toot toot Lemme give you that beep beep Runnin’ her hands through my ‘fro Bouncin’ on 24’s While they sayin on the radio This is the remix to ignition Hot and fresh out the kitchen Mama rollin’ that body Got every man in here wishin’ Sippin’ on coke and rum I’m like so what I’m drunk It’s the freakin’ weekend baby I’m about to have me some fun Crystal poppin’ in the stretch Navigator We got food every where As if the party was catered We got fellas to my left Honeys on my right We bring em both together we got junkin’ all night Then after the show its the (after party) And after the party its the (hotel lobby) Around about 4 you gotta (clear the lobby) Then head take it to the room and freak somebody Can I get a toot toot Can I get a beep beep Runnin’ her hands through my ‘fro Bouncin’ on 24’s While they sayin on the radio It’s the remix to ignition Hot and fresh out the kitchen Mama rollin’ that body Got every man in here wishin’ Sippin’ on coke and rum I’m like so what I’m drunk It’s the freakin’ weekend baby I’m about to have me some fun This is the remix to ignition Hot and fresh out the kitchen Mama rollin’ that body Got every man in here wishin’ Sippin’ on coke and rum I’m like so what I’m drunk It’s the freakin’ weekend baby I’m about to have me some fun Girl we off in this jeep Foggin’ windows up Blastin’ the radio In the back of my truck Bouncin’ up and down Stroke it round and round To the remix We just thuggin’ it out
Yea, the problems you encountered in this reaction are coming from the sodium carbonate which disolved the traped micro-clusters of natural human oils (from the jeans)and formed a complex mixture of sodium soaps + the inteference of sodium metabisulfite is to blame because the alkali-earth alkali metabisulfites are known `pyrodiscolorants` not to be confused with NaClO which is a ´heavy oxidasion type discolorant´.
Having watched several different articles on this website, I’ve got a couple of suggestions that I’d like to see you do: • With the current problems with infrastructure that are happening worldwide, I’d like to know some of the alternate methods for removing the lead compounds (leached from ancient lead pipes) from contaminated water to make it potable again. • There’s an extraordinary material I’d love to see you try to make – Aerogel . It’s got so many amazing properties, such as extremely low density & excellent thermal insulation.
@Nilered as far as i can imagine and with a very superficial scan of the literature, the oxidized indigo has two pka values being the first around 5-7 and the second 11-13. Maybe the monobasic enolate form of the dye is blue but still soluble being a K or Na salt. This is a guess i made, not anything said with certainty.
I’m not sure??? How I’ve watched this guy for years and am definitely subbed to Nile blue but not to red?? Also have you considered the fact that maybe you just. Discovered the thing with the base (I’m not a chemist) and that’s genuinely what happened but indigo is a really niche subject so no one else realised?
9:32 wouldn’t it be a acid base reaction so when the hcl forms with the naoh it forms salt? therefore if the indigo was bonded to the base somehow it now has nothing to bond to so it precipitates out since it’s not (very) soluble in water? personally i don’t know i’m only 16 but that’s what i was thinking lol, keep up what you’re doing.
Here’s my theory on why it stayed in solution: I think what is going on is that oxidized indigo can do this crazy proton transfer keto-enol isomerization of the ketone with the indole amine (google “asian textile studies indigo”, first page, search for “the indigotin chromophore”) makes the amino hydrogen more acidic than it ought to be in isolation. I don’t think aq. NaOH by itself can deprotonate it, but if you reduce it, then let it oxidize, perhaps the proton gets “stuck” and you are left with the sodium salt of the mono-enol indigo. Just speculation. Either way, there is definitely more than meets the eye here, like Thunderfoot and the Coulomb explosion.
Rit makes a dye-removing powder that I tried on a jean jacket. It did a great job of transferring the indigo from the fabric to the entirety of my washtub, so maybe you could find out what chemical that is and recreating the process? The packaged form was pretty cheap so I assume the base components are too
We use sodium dithionite and sodium citrate to extract Fe and Al from soil for mineralogical analysis. Similarly Oxalic acid and ammonium oxalate to do the same for Si, Al, and Fe (poorly crystalline forms). Using a salt to help suspend and hold the extract to obtain higher yields. Additional freezing the solution will cause precipitate to form for recapture.
Correct me if I’m wrong (because I probably am) but is it possible that the NaOH, being such a strong base, just deprotonated the nitrogen in the indigo and made it polar enough for a polar solvent like water to dissolve it (not to mention the water being protic and interacting with the deprotonated nitrogen)? Then again, I don’t see why it wouldn’t just dissolve again in the acid, considering the fact it would probably protonate the oxygen and nitrogen in the indigo and make it polar. Maybe as each oxygen is more or less opposite a nitrogen, the dipoles cancel, or maybe water being protic has a much more important effect than it being polar, so it would dissolve the deprotonated, slightly polar indigo, but not the protonated, (maybe) slightly polar indigo.
When you added sodium dithionite you accidentally sulfonated your indigo dye to produce indigo carmine. Dithionite produces Sulfite and Sulfate salts when reacted with oxygen. These can perform an electrophilic aromatic substitution on indigo to form indigo Carmine. Additionally Indigo Carmine desulfonates in dilute hot acid. It’s unclear whether you protonated or desulfonated the Carmine. Indigo carmine is used as an indicator with a yellow color around pH 13 and blue below that.
Looks like the specific combination of chemicals you were using included something that was allowing the indigo to be soluble in water, much like how soap allows fats to be soluble in water. When you add the acid, it neutralizes that substance (or at least the effect) and the indigo precipitates out. No idea what the specific combination or substance is that’s causing it, though…
I had a pair of jeans that had so much dye in it my hands were turning blue and I didn’t know why. It was from putting my hands in my pockets for 5 seconds. That would have been a good pair to extract from lol. After o washed them once it wasn’t as bad but still a bit of dye would come off. And this is the pocket lining where they don’t even look that blue.
why not just dissolve the cotton? copper sulfate is rather cheap as an algaecide, the ammonium sulfate from precipitating the rayon can be recycled to reproduce the schweizer’s reagent and sulfuric acid, and the indigo would just precipitate out of the viscose solution. i would NOT use a fritted glass filter you like for this.
upon looking at the Indigo molecular structure, I see that it has two protonated nitrogen atoms, both at the 5side rings, at the center. Maybe at high pH these are de-protonated, which in turn creates two charged dipoles, which in turn may increase solubility in water? and when you decrease pH, it gets protonated again and decreases solubility. just brainstorming, maybe wrong, donno.
Great article, FYI, indigo Carmine will deprotonate above pH 13, so it’s possible that the indigo would as well. However that form is a green NIR dye. Most likely what happened is you had incredibly fine particles. If you end up making Carmine, consider doing the stoplight reaction… It’s so cool, and call be gorgeous.
I wonder if the reason the hcl kicks out the indigo is because it’s actually present as a colloidal dispersion not a fully dissolved solution (but too small fonthe coffee filter to catch) . These particles could be charged and have an acidic isoelectric point. If you don’t want it acidic or to test this idea, you could try adding a good amount of divalent salt (eg CaCl) to destabilize it.
The indigo has 2 vinylogous amides with both carbonyls conjugated together. Additionally, it is also essentially a 2-acylaniline dimer and the electron withdrawing carbonyl decreases the electron density on the aniline nitrogens making the N-H protons more acidic. With this combination of functional groups and the presence of several pathways for the negative charge to be delocalize, the base is probably able to deprotonate one of nitrogens to generate the water soluble anion.
I would suggest if you do this with the whole pair of pants, that you do 3 or 4 extractions instead of simply 2, to get a higher yield, and make sure the pants are thoroughly cleaned afterwords, and tested to make sure none of the chemicals used are still in it, because I imagine they’d look cool as just pants to wear. but I mean I don’t know if any of those chemicals would stick around in the pants after drying.
my shot of what is happening is the other compounds of the iron out make a complex with the indigo in the presence of the sodium hydroxide what can explain the yellow-green color from the reduced compound and explain why the mixture dont precipitate when oxidized. sorry for my grammar errors, im from brazil kkk
Please make CS gas or at least the precursors. I find that it is much more useful than silicon tetrachloride. Even if it is harder to make I would much rather use it if or before shit hits the fan and pepper spray isn’t so effective against polycarbonate shields and lasers are and are even easier to make. Yes I realize that trump will likely have a second term about the indigo. From what I understand the malononitrile is actually useful in a few different reactions. Maybe that’s worth looking into. Thiols are interesting too. I just don’t agree with the eye burning and the nauseating not being assembled together in terms of a free assembly and I don’t want to assemble it with death or being so permanent. I understand the indigo turns red and clear in two runs and oxidized.. maybe the reason cs gas is so hard to make and worse things are easy and available is somehow related to why acid causes it to precipitate and how that is so hard to understand. Trump said only losers (I think he said bitches or pussies or something) press charges. And Jesus said “I am the light and the way” and one sows and another reaps.
Did the citric acid in the Iron Out keep the pH in just the right range where the leucoindigo salt was still present in significant amounts, and making the solution more acidic increased the concentration of indigo past the solubility threshold? Or is it possible that the citric acid was protecting the indigo molecules somehow in some complex (instead of its usual intramolecular hydrogen bonding)?
I’m pretty sure that because the material of indigo are pretend to stick stronger in denim clothes. Using inorganic substances to extract dye in a clothing that does anything because the acts of basic indigo-dye due the strong bonding through the denim clothes. Using organic solvent could be though because the bonds between indigo-denim are dependant of their hydrophobicity. Using inorganic substance would eventually broke the bond between indigo-denim that turn denim into colorless.
i would’ve removed the fabric asap, as in as soon as it appeared colorless, i also would’ve used the left over fabric until it was snow white. simply just because since i know you liked to have a small surplus of chemicals so i feel like it would’ve been the smartest and most useful way of doing it, but i know this is 2 years old and i’m not a chemist so you definitely know more than me
15:44 that photo is very generic but it also is funny. However, I think that the hcl additions was necessary because the reduced form is also a sodium salt of indigo . The hcl was able to form nacl with the Na+ ions in the reduced form which then was oxidized into indigo by air trapped in the solution by stirring
we did this back in school, but i dont remember which solvent we used. i only remember that nothing worked and we used some sort of solovent combination ( fE water and ethanol) maybe that idea helps gettin it cheaper^^ ah now i remember we ended up reducing the indigo too and yes it was in the range yellow green^^ i suggest burning the jeans in case the indigo wont be burned at those temps my idea with the indigo gettin knocked out by a higher ph would be that it reacted chemically with it or the factory that produced those jeans didnt use “real” indigo
I legit know nothing about indigo or the stuff you added to it but maybe it had to do with the iron out stuff and maybe that was keeping the indigo dissolved. When you added the hydrochloric acid (I think it was) maybe something reacted with something in iron out and made the indigo fall out. Idk tho
My guess is that the indigo is more soluble in water under basic conditions and when we add HCl we turn the environment acidic. Also when we add the HCl we create NaCl and that’s a way more soluble salt compared to the indigo making it crash out of the solution. The only reason I think this is because in his recreating the weirdest chemical reaction article, FeSO4 was oxidized to Fe2(SO4)3 and that was less soluble and fell out of solution. But again I don’t even have a Bsc in Chemistry and am just a high school student, so feel free to correct me if I’m wrong. PS Love your website 💙💙
It seems likely for indigo to form a sol (colloid), that’s why it stays suspended in the alkaline medium. If the colloidal particles are negatively charged (and it’s quite common for different sols in alkaline medium), then they usually need only a small conc. of strongly binding cation to become neutralized, and then, to precipitate (because the electrostatic repulsion dies off). And, one of the strongly binding cations is… acidic proton 🙂
Looking at article, it seems that soxhlet extraction should be pretty good (and clean with low amount of wastes) in this case (like @12thealchemist wrote). As for reducing bath… Maybe better approach would be not cooking denim in solution but to put very small pieces (long time with scissors or maybe some paper shredder) in long glass tube and elute indigo with hot solution. Indigo reduced form concentration gradient should help to wash out maximum, and in the same time, a little of glass wool at the end, would filter off fibers.
My theory on the blue solution of indigo has always been that the precipitated particles are actually so small that they pass through things like a coffee filter. I would advise you to try and use a little bit of Potassium Alum as a flocculant in order to create larger clumps of Indigo pigment, that should make filtering possible. For the purpose of dyeing the Alum contamination should not pose a problem as the Alum is often used as a dyeing mordant in the first place. It is exactly this method I often use to recollect my indigo dye waste. On a sidenote: you might not want to bring the solution to a boil. I know that some sources suggest that Indigo starts to decompose near the boiling point of water. Perhaps this also decreases your yield?
I was playing with acetone and denim earlier today! The knee of the pants was stained blue with paint from a mural I did. The lighter parts of the jeans actually made it match fairly well, I was trying to get some of the paint out I happens to have acetone out so decided to give it a shot, I have yet to examine the results but it seemed to blend it better . It’s still rather a shame because I had considered those one of my nicer pairs and I usually forget the stain until I’m out in public. Oh well I’m an artist I’ll wear it proudly
I loved Ignition. You will never find a more honest book about the development of rock fuel throughout history. It really does go into all the gory details without sacrificing the technical details that became our collective knowledge of rocket fuels. It doesn’t matter if your a layman, chemist, physicist, rocket scientist or whatever; that book really does have a lot of offer to the reader.
I don’t really see how indigo could form an acidic ion but perhaps you were just having a problem with a really stable suspension (maybe lye kept the indigo molecules finely dispersed, incapable of either aglomerating or staying behind in a simple coffee filter) then again they didn’t teach us diddly squat in pharmacy school so dunno, blame it on indigo leprechaunts if every other theory fails
there’s citric acid in the iron-out preparation, no ? might explain why it was able to keep the indigo dissolved in basic aqueous solution, but not an acidic one ! citrates do have chelating and other properties relating to phases after all. might have a lot to do with the acidic/basic forms of indigo and how they occupy space, too. the acidic form is planar with a shit ton of mesomerism and not really polarized, but according to wikipedia it dissolves well in chloroform… but not ether ?? it may be more of a soft-soft thing than a dipolar moment thing but idk (maybe the wikipedia article needs to be revised, too). and what’s its most stable basic form is a whole other can of worms. needs more experimenting for sure, there seems to be a lot of contradicting sources on internet wrt/ the solubility of indigo !
so, since you like more practical experiments, would you have any interest in doing a article on synthesizing iron acetate, and the reaction and products of iron dissolved in acetic acid, iron dissolved in hydrogen peroxide then mixed with acetic acid, and dissolving iron with the hydrogen peroxide + acetic acid mix dubbed peracetic acid? I’d really like to see some of the reaction formulae and balanced equations. The iron acetate is used to ebonize wood, which also might be an interesting reaction to look at.
My guess on the solubility fix is that the NaOH you added in advance of the iron-out deprotonated the secondary amines and allowed for the salt to form between the indigo and iron out. The HCl in turn protonated the indigo preferentially allowing it to return to its normal crashing out behavior in water
Doesn’t the addition of the acid causing the indigo to precipitate make sense based on what you earlier said/implied? The indigo has low solubility in water in its neutral state, but when you reacted it with the base solution, you got the sodium salt, which seems to be quite soluble. Acidifying it re-neutralized the indigo and you got it to crash out and the sodium went to NaCl.
Try dissolving a little of your product in some NaOH solution to see if it is soluble under basic conditions or if it was something in the iron causing it to remain in solution. It’s interesting that the addition of HCl caused it to precipitate and leads me to think that somehow, some way, there is a deprotonated a hydroxy group or salt (which shouldn’t exist after oxidation). If it was fully oxidized, maybe the nitrogen was deprotonated, forming an imine and an enolate (possibly an enolate salt…). Let’s call it “conjugated tautomerization”. Yeah, that sounds scientifical!!! If that is not it (using a lot of imagination here), it may not have been fully oxidized, leaving an enolate salt on one side of the molecule…. which is hard to believe.
Perhaps you should hook it up to to another to containers. Take that first make your chemical bath in it on a hot plate with a tube hooked up at the bottom of it then hook it up to the second that holds the main reaction and hopefully could be free of air contact. Then hook it up above the denim to the third that stores the used solution. Hopefully with this setup you could get a better yeald and simply gravity feed the first to the second once the mixture is up to temp.
As to why Indigo dye would dissolve in basic conditions and precipitate in acidic ones, the only possibility that comes to mind is that the two secondary amines in the indigo would react to differences in pH. This is slightly puzzling though, since amines are generally weak bases and would logically be more soluble in acidic conditions, where they are protonated into cations, than in basic ones. This is the exact opposite of what we see in the experiment. However, after some research (I am an inorganic chemist so don’t take my word as gospel here) it seems that acidic amines do exist. These are amines where the R-groups on the amine cause hybridization where the free electron pair of the nitrogen is delocalized in a resonance structure or has too much s-character to properly bond to hydrogen. One example would be pyridine where the amine group has a pka of ~5,2 Since I’m no organic chemist I can’t be sure, but the amine groups in Indigo sit very close to aromatic 6-rings and a central double bond, so I think a resonance structure that may delocalize the free electron pair might be possible. If so then the amines may be acidic and the hydroxide can deprotonate it into a soluble anionic form. It’s a stretch, and it goes against the general convention of amines, but it’s also the only thing I can think of.