Synthesizing bromine

[Andy Stockton]

You inspired me.

http://www.plastomertech.com/bottlecaps.htm

Still haven’t found prices or a retail supplier, but I will look.

[Mercury]

Andy, I await with brominated breath….

Photolytic, I’ve experienced the same thing. I think some manufacturers expect that the product will be used up in a short period of time, i.e. months.

[photolytic]

Here’s the Fisher Bromine bottle. I had to tape the label back on but it’s ok otherwise.

The cap has a white plastic liner (teflon?) stained a light orange from the bromine.

 

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[Andy Stockton]

Interesting resemblance between the Fisher bottle top and the Plastomertech product. Does the Fisher bottle top have a number imprinted on it? I have written to Plastomertech requesting information on a retail supplier.

 

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[photolytic]

No number label on the cap Andy. It was made long before recycling was popular.

The cap looks like the ones you posted with three concentric circles on the top.

The cap is hard and not transparent. It’s probably number 4, ABS (acrylonitrile, butadiene, styrene) which is relatively resistant to aqueous acids, alkalis, concentrated hydrochloric and phosphoric acids, but is attacked by concentrated sulfuric and nitric acids.

[jgmotamedi]

The image of the Fisher bottle cap which photolytic posted also looks very similar to the Spectrum bottle I had a few years ago. I never thought to keep the bottle or look carefully at the cap. Mostly I kept the bottle as far away from me as possible.

Andy, if you do find any access to the all-PTFE caps please do let us know, I would certainly buy a handful. I ended up ordering a 30ml PFA vial and cap, which should be enough space for my purposes right now, as I have no particular need to store more than I can easily use. However I may order one of the smaller PTFE bottles and compare the results.

I will be running one more synthesis this weekend, and will attempt to careful document it with images so others can try.

[CasedImage]

Thought I would add to the Bromine pics, I bought this 250ml of bromine about a month ago and have used some of it, actually Andy’s find of the small dripper bottle looks a good way to decant some. So far in storage not a wiff of bromine around the cap, early days though.

 

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[Andy Stockton]

Ken – what a great find! I hope you will be sharing other portions of this legacy in the various areas of the forum.

[jgmotamedi]

Ken,

Thanks for the link and research. This is very helpful and I will study it in more detail this week. Essentially, the process outlined by our Renaissance Man is very similar to that which I have been using. We both started with a bromine salt (I used NaBr he used KBr, the main difference is that NaBr is more soluble so I could use less water) and then used an acid (H2SO4) to make HBr, and then an oxidizer (MnO3 versus my use of KBr03) to pull the bromine from HBr. In fact, I suspect that nearly any strong oxidizer would work, such as potassium permanganate or any of the brominating tablets used for pools. The main difference is that our Renaissance Man is distilling the bromine, while I am not. His product was probably purer than mine, but I don’t know how much. My last attempt used 40g of NaBr, which gave me nearly 10ml of bromine, so the output is quite similar. I would like to see his tables and other data, this could be very helpful.

jason

[photolytic]

Despite requests from this forum for more input from experienced chemists, I have hesitated to offer suggestions for the synthesis of dangerous chemicals like bromine, because I do not believe photographers with limited chemical knowledge should be encouraged to risk their health and lives making something that they could purchase, even at considerable cost.

Both Ken and Jason have offered good suggestions for modifying the Bromine synthesis reaction. The use of manganese dioxide @$4/lb is certainly preferable to the more costly KBrO3 as an oxidizer. However since no temperature requirements are mentioned in the referenced literature one may assume that more heat and /or an excess of one of the reagents may be necessary drive this reaction to completion.

I am a bit disturbed by the reliance on tables of chemical quantities for reaction recipes. Perhaps I am wrong but it appears that limited attention is being paid to the principles of chemical stoichiometry here. Unless one has first mastered the skill of calculating reactant quantities from the molecular weights and concentrations of the components in a balanced chemical reaction, there is a very real danger that the chemical experimenter may make the fatal error of assuming that “more is better”. This could be a real danger in the synthesis of a dangerous material like bromine.

[jgmotamedi]

Photolytic is absolutely correct that this is a very dangerous process and perhaps a very foolish endeavor, one which my few years of college chemistry do not prepare me. I have also been guilty of not sharing all of my information assuming, perhaps incorrectly, that no one was going to jump in the water with me quite yet. Ramping up chemical reactions, particularly exothermic ones like this, is unpredictable and can be incredibly dangerous. Mixing acids and oxidizers can lead to disaster.

That said, I assume the heat requirements for the Renaissance Man’s bromine synthesis is to the boiling point of bromine, or 58.8C/137.8F. Of course, this only reinforces Photolytic point, as I would be very reluctant to heat bromine, making it even more volatile and dangerous.

[Mercury]

Photolytic’s points are well taken. There is considerably more background to the information that I posted but I kept it short, figuring that 1) I didn’t want to bog the blog down with too long a post initially, and 2) if anyone had any questions about the background (including a thorough calculation of the molecular weights of the reagents involved and a balanced chemical equation) I could either post it or supply it individually. This “Renaissance Man” as he is coming to be known I guess, did not rely on any table of chemical quantities for his reaction recipe. Rather, he found the equation, then did make his calculations using atomic weights and concentrations of the components. It’s all in his notes.

I should have applied a more cautionary tone, however. Photolytic, I’ll pull my posting until you’re satisfied with the stoichiometry. If you would like to see the complete dossier I’ll be glad to scan it for you, but since I’m leaving for France in under two days, that will have to wait 10 days or so.

I must admit being caught up in the excitement of being able to share this information with others who are already working in the same vein.

[CasedImage]

Hello all, post deleted as requested, a good example of the community governing itself. Ken is endeavouring to put together info on the “Renaissance man” for posting on cdags, I think we all look forward to hearing about him.

www.CasedImage.com

[Andy Stockton]

On a simpler note I am happy to report that a sample unit of the all PTFE bottle cap is winging it’s way to my house for testing from Plastomertech. I have sent for an appropriately sized PVC reinforced amber glass bottle from another company as well. When I have both in hand I will decant my Bromine to the new bottle and begin a testing cycle. I will let the membership know the results. Of course since a long time trial is the only definitive answer, I will be reporting periodically for a while.

Plastomertech requires a $150 minimum order, and in small quantity the 28-430 size cap is $11.37 USD each. Once I have completed some testing I would be happy to put together a group order for those who are interested. (I may add a small surcharge to help support the CDags hosting costs if people are supportive of that that).

[photolytic]

Ken,

I found nothing wrong with the balancing of the equation nor did I have any doubts as to the former abilities of the “Renaissance Man” to carry out many chemical procedures.

I was concerned that there was considerable risk if these formulae were passed along to unsuspecting chemical neophytes.

As you wisely cautioned there are dangerous articles out there like Mark Baczynsky’s “How to Make a Daguerreotype” that contain instructions for making Dags, which are “dangerous and must not be followed”.

I consider a procedure for making bromine to be too dangerous unless performed by an experienced chemist in a commercial fume hood with good ventilation.

Have a good trip to Paris and take lots of pictures of our Dags.

John

[Mercury]

John, thanks for the confirmation on the balance of the equation and for your concern.

Thank you too for bringing up Baczynski’s “How to Make a Daguerreotype.” That should stay current as a definitive guide for how NOT to do things.

I’ll definitely be thinking about how to balance this philosophical equation, since as far as passing risky information to unsuspecting chemical neophytes is concerned, we’re way too late! It’s already out there on the web via a simple keyword search, often uploaded from printed books that have been in circulation for decades, with far less cautionary information than has been exchanged in this thread on CDags. (The book I cited in my original post actually says “This method of collecting pure bromine by distillation is relatively safe.” I think that is a gross underestimation of the risk!) The book’s introduction is entitled “To the Teacher” and states that it is written “…for young people who are learning to be citizens.” (A dose of cold-war rhetoric, I think.)

I don’t believe we have been advocating or giving specific instructions, but rather exchanging information. I agree that we have, however, failed to appropriately salt our exchanges with cautions about the very real dangers of trying to reduce this information to practice.

So I ask that this discussion continue, since it ultimately has bearing on every aspect of daguerreian chemistry and the elements involved!

Respectfully,

Ken

p.s. And yes, John, I’m looking forward to LOTS of pictures! It’s our moment.

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