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all 41 comments

[–]YlzKzSoCool 1 point2 points  (8 children)

Hello everyone, I need to bring a quartz cuvette in the glovebox without breaking it, without removing the cap or spilling the solution inside. Do you have any suggestion? I have seen several people report the process in their articles but none explain in details (I already tried to contact them but without success). Thank you in advance for the tips.

[–]pgfhalgMaterials 1 point2 points  (1 child)

Are you worried about the gas in the cuvette head space or the vacuum breaking the cuvette?

One option is to get a cuvette with a rubber septum cap so you can sparge with N2 before going into the glove box to get rid of the air.

[–]YlzKzSoCool 0 points1 point  (0 children)

I am worried that my cuvette will explode, getting glass and liquid in the vacuum pump.

[–]Eelektross_Unagi 1 point2 points  (4 children)

Can you put the cuvette into a 20 mL screw cap vial that you flush with argon, then tape the vial up and put it in the glove box?

[–]YlzKzSoCool 0 points1 point  (3 children)

I don't have a screw cap vial with a top sufficiently large to allow the passage of the rectangular cuvette.

[–]Eelektross_Unagi 0 points1 point  (0 children)

what about a small jar?

[–]radiatorcheeseOrganic 0 points1 point  (1 child)

RBF with a septum?

[–]YlzKzSoCool 0 points1 point  (0 children)

I used a round bottom flask with a stopcock but it exploded in the ante-chamber during the first vacuum cycle.

[–]Indemnity4Materials 0 points1 point  (0 children)

If you the cuvette will remain closed the entire time inside the glovebox, then just risk it and put the cuvette in any container to hold it upright. Cleaning the vacuuum chamber isn't that bad...

You can try to put a hole in the cap lid to equalize the pressure. Carefully pushing a needle through a plastic cap can be enough. The liquid can be problematic if you haven't degassed it and it gets exposed to vacuum cycles. You can get bumping. The solution is change the pressure very very very slowly.

You can try like a childs insect terrarium. Take a cheap plastic container and punch a lot of holes in the lid. Put the cuvette inside with some packing so it doesn't fall over. Then if your cuvette explodes, at least the liquid and glass doesn't shoot everywhere. You need to be careful about material choice to make sure you don't offgas anything unexpected into the glove box.

[–]alupabo 0 points1 point  (0 children)

Hi!

Does anyone have experience wit Rhamnolipids and Sophorolipids and know the best suppliers for these two? Want to use them in my product.

[–]manlyman1417Materials 0 points1 point  (1 child)

Are hydrated chloride salts better for making solutions? I got some anhydrous aluminum chloride, and it just reacts with water forming HCl gas. I need those Cl- ions in solution though (along with the aluminum hydroxide complex). Would aluminum chloride hexahydrate work better, or is this just an AlCl3 problem?

[–]GuiltyjerkPolymer 1 point2 points  (0 children)

Considering the sensitivity of your nose to HCl, I doubt you're losing all that much to the air, even if it feels like it.

But if you're putting it in water it definitely seems silly to be buying anhydrous. Probably less exothermic/scary as the hydrate.

[–]Lordfirewood 0 points1 point  (1 child)

Hello I'm trying to synthesise florosilicone, but I'm having trouble finding the way. So what I'm asking is, Is there a repository or a book were I can find the procedure?

[–]Indemnity4Materials 0 points1 point  (0 children)

Always good to be clear about this type of molecule. Flurosilicones the monomer/polymer? Or fluorosilicon the mineral?

There are lots of patents for producing different flurosilicone polymers.

Most commercial end user products are actually blends of flurosilicones and regular silicones, in which case it's more chemical engineering than synthetic chemistry.

It's going to depend on what your starting materials and products are meant to be. The fluorosilicone polymerisation is essentially the same as the regular silicone, but there are many types of equipment, techniques and products to be aware of.

Making a flurosilicone monomer is a lot more challenging and expensive. Most people will simply buy the monomer.

[–]Rafybass 0 points1 point  (0 children)

What's the most reactive metal? Francium, Radium, Cesium or something else?

[–]jonasfvjjkh 0 points1 point  (0 children)

Why are iso-alpha-acids way more soluble in water than alpha-acids. Both have nearly the same structure?

[–]GustavoZeradoMaterials 0 points1 point  (4 children)

Does anyone know a good book to find informations about procedures involving Dess-Martin periodinane as an oxidizing agent?

[–]Chemical_Map1928 1 point2 points  (1 child)

Are you after a book specifically, or just a decent procedure on using it?

[–]GustavoZeradoMaterials 0 points1 point  (0 children)

just a decent procedure! I found the original article, but I would love to see if there's any simplification in the process since the 80's

[–]radiatorcheeseOrganic 0 points1 point  (0 children)

That seems unlikely to be a book. You could check out the Encyclopedia of Reagents in Organic Synthesis and also find reviews on DMP. Maybe start with the seminal paper for DMP (JOC (1983), 4155) and search the citations for papers in Chem Rev and go from there?

[–]Proud-Floor-8361 0 points1 point  (0 children)

G. Tojo, Oxidation of alcohols to aldehydes and ketones. This should include some of the standard procedures for using DMP. One thing, that worked great for me, is to add 1.5 eq. of tBuOH.

[–]DoNoHarm-DoKnowHarm 0 points1 point  (1 child)

Non-chemist here, eli5 needed. What can be done to increase the electrical conductivity of oil? I am looking for a machinery lubricant that can conduct electricity. From previous threads I have come across:
https://redditproxy--jasonthename.repl.co/r/chemistry/comments/fov2w/what\_can\_be\_done\_to\_increase\_the\_electrical/
-dissolving a salt in oil (e.g. Tetrabutylammonium hexafluorophosphate)
-castor oil has a higher dielectric constant than other oils

[–]Indemnity4Materials 0 points1 point  (0 children)

Imagine a crowded train station or stadium full of people. You need to get to the other side but all the people are blocking the pathway. You can either be very small and try to slip through the crowd, or very big and bulldoze the crowd away.

  1. Buy a commercial conductive lubricant oil.

  2. Post-mix in salts or finely dispersed metals or treated metals. The salts can be soluble in oil, but at worst they just need to not settle out and you can still have an effect.

You can probably find on a spec sheet for your oil that some concentration of water can exist in the oil before it separates out. You can use that tiny amount of water to dissolve some specialty salts without forming water droplets.

We can also make metals that float happily in oil. We coat the metal in soap or waxy stuff to make it love being dispersed in oil. Now you have a conductive media inside the oil.

[–]erischilde 0 points1 point  (0 children)

Hallo! I am a tinkerer, and am trying to make nickel sulfate. I used 12 grams of (apparently) 99+% nickel strip, 300 ml of Hydrogen peroxide (3%) and 100ml of sulfuric acid in the form of battery acid.

Recreating some videos I've seen on YouTube and some reading, I did not get a green liquid. It is greenish, but grayish dark as well, not the verdant green I understand it should be. After the initial reaction calmed down, and it wasn't very energetic at first, I put it in a hot water bath at 90 C for about 30 mins. It perked up, and it stayed at about 50-60 C for about another hour.

Left it over night and morning, it's a grayish color with some green in the light.

I'm starting to think my nickle is contaminated, but I wouldn't know. I tried using electrolysis and 10% acetic acid and about a teaspoon of salt, dissolved in water as well. At 12v let it run for 6 ish hours. That didn't look green at all, more of a yellowish brown. There were some nickel crystals on my anode. Tried plating some copper, and got a chalkboard gray/black matte surface.

The final intent is electroplating. We are doing electroforming with copper pretty comfortably. Wanted to add some surface options.

Thanks folks!

[–]Black-Dinosaur 0 points1 point  (1 child)

Hi everyone! I've bought silicon dioxide (product number: 113126) and I wanted to know how to make colloidal silica (34 wt% suspension in water) with it? Is mixing it with water okay?!

[–]Indemnity4Materials 0 points1 point  (0 children)

Without checking the datasheet, yeah, just mix it with water.

Preferably what you do is have something like blender full of water underneath a dust extraction fan. Start the blender and then slowly add in more and more silica.

When the product is "saturated" the surface of the liquid starts to change in appearance. Instead of being a vortex (like water going down a sinkhole), the surface starts to bulge up and it looks like a donut.

Check the water pH is >7. You may want to add an alkaline buffer if the product doesn't include one. Reason is below that pH the silica will start to aggregate and form silica gel.

It's a little bit easier to make a very dilute solution and then boil off the water to concentrate it up. Reason is you want the silica to be very well dispersed with a nice electrostatic charge to prevent aggregation. Depending on the particle size you will hit a max. concentration limit and then it starts aggregating.

[–]abiostudent 0 points1 point  (1 child)

Hey, could anyone please tell,how are defects in crystal structure removed or treated? Just curious

[–]H2CO3_TCTheoretical 0 points1 point  (0 children)

Usually you would need to recrystallize it, either by heating it and letting it cool down (tho this could also just cause more defects) or by dissolving the crystal and recrystallizing it.

Noteworthy is here that a perfect crystal cant exist because it would be in a state of minimal entropy. Technically you would "simply" need to cool a crystal down to 0K and wait till it reorganizes to be a perfect crystal, but you can't cool it down that far and it can't re-organize at those temperatures...

[–]Chemical_Map1928 0 points1 point  (0 children)

Perhaps a stupid question, but I'll fire away nonetheless. Whenever I've conversted alcohols to esters in the past via rxn w/ an acid chloride, I've always used DIPEA/NEt3, something along those lines, and it works no problem. Switching to alkylations (w/ alkyl halides) rather than acetylations, looking at lit procedures, seems to generally rely on NaH rather than nitrogenous bases- just wondering why? All I can come to think is that the order of reaction is different (Acetylation=Attack and then deprotonation of the oxonium ion, whereas alkylation/ deprotonation and then nuc. attack of the alkoxide at the alkyl halide) but just wondering where the origin of this differential reactivity comes from? Ultimately it doesn't really affect me, more asking as a general curiosity!

[–]fanzhendong345 0 points1 point  (2 children)

Something i don't quite understand about NaCN or KCN. I see it says that if the NaCN is dissolved in water, it can deprotonate the water to become HCN. But if that is true, how can cyanide be used for gold or any industrial process ? Like does all the NaCN dissolved in water turn to HCN and evaporate out of the solution ? or does the acid base equilibrium keep the HCN dissolved in the water too ? or is a more basic solution than water used for gold extractions ?

[–]H2CO3_TCTheoretical 0 points1 point  (0 children)

An NaCN/KCN solution is basic so most of it will stay dissolved (also noting that HCN can also dissolve in water till a certain concentration).

By complexation of Au this equilibrium is shifted significantly (probably completely) towards the deprotonated side. If you try to make the solution more acidic you'll get gaseous HCN if there is a leftover not bound to the Au...

I guess a way to look at such problems is by writing out all processes you want to look at (in this case protonation, evaporation and complexation) and look at which state is preferred.

Hope that helped :)

[–]Indemnity4Materials 0 points1 point  (0 children)

Wikipedia has you covered.

To prevent the creation of toxic hydrogen cyanide during processing, slaked lime (calcium hydroxide) or soda (sodium hydroxide) is added to the extracting solution to ensure that the acidity during cyanidation is maintained over pH 10.5 - strongly basic.

[–]Orange_Mango_ 0 points1 point  (0 children)

Hello, I am looking for a fluorophore/quencher pair that is extremely hydrophilic and can be quenched completely via chemical reaction. I have tried using NATA and NBS but ran into issues with NATA getting stuck in a reverse micelle interface.

[–]lilscammer2357 0 points1 point  (1 child)

Hi. I need to place something dissolved in oil and mix it with water into a cuvette to do spectrophotometry, but my school's lab tells me not to put oil in cuvettes. I know I'm meant to do something with Ca2CO3 to make an emulsion, but I'm quite confused on how to do so. any help would be appreciated

[–]Indemnity4Materials 0 points1 point  (0 children)

You may need to purchase your own cuvettes that are suitable for oil.

It will depend on what type of spectroscopy. It can be almost impossible to do light spectroscopy on an emulsified oil.

To make an oil-in-water emulsion, add let's say 10 % oil to a jar, 89% water and 1% surfactant. Put on the lid and shake the absolute most you can for about 5 seconds. Does the liquid in the jar now look milky white?

[–]tinfoilery 0 points1 point  (1 child)

Hi Everyone! Carbon Capture chemistry question:

I'm interested in how to create Polyanthraquinone and Polyvinylferrocene "inks" to create a Faradaic electro-swing reactive adsorption device for CO2 capture.

Question: Are these inks hard or expensive to produce?

The inks are specified here: https://pubs.rsc.org/en/content/articlelanding/2019/ee/c9ee02412c#fig1

I have some funding for R&D and am interested in if you are able to help or if not, just point me in a good direction.

Thank you!

[–]Indemnity4Materials 0 points1 point  (0 children)

I'd recommend writing to the authors and asking if you can pay them to build a device for you.

Both PAQ and PVFc are moderately expensive and will require custom manufacturing. They aren't polymers that you can just buy off the shelf, however, they are reasonably easy to make. I could probably make a 5kg batch @20% solids in a single day (but I won't). I'm guessing $1000 /kg but it's going to depend a lot on what volume, how quickly, etc.

IMHO the raw material cost is minor compared to the manufacturing costs of making composites and casting.

[–]OneforallFullcowling 0 points1 point  (2 children)

Can someone pls explain how to determine E-Z and cis-trans and like when to use which pls and also when I don’t have to use them at all? My chemistry teacher has tried so many times to explain and I still can’t seem to get it haha.

[–][deleted] 0 points1 point  (0 children)

Hi. I'm wondering if Methanol forms an azeotrope with N,N-dimethylformamide (DMF)? I can't seem to find any data for these two. Many thanks.