asilentbob Posted April 16, 2006 Posted April 16, 2006 Okay, im sure many of you have thought about crackling microstars AKA dragon eggs and have been held back because of one of the oxidizers most commonly used:Pb3O4 = Red lead, lead tetroxideBi2O3 = Bismuth(III) oxide(BiO)2CO3 = Bismuth subcarbonate (BiO+ is the bismuthyl ion, more below)If you do not know, crackling microstars AKA dragons eggs are little (1-2mm) chunks (usually grated through a screen to get the chunks) of composition that burn very fast and pop/crackle very loudly for their size. Good stuff! They are binded with 10% NC laquer. The 3 most typical compositions are:Bi2O3 - 75, Magnalium (-200mesh) - 15, CuO - 10, +5 atomized -200mesh AlPb3O4 - 70, MgAl - 17.5, CuO - 12.5, +5 AlPb3O4 - 81.8, MgAl - 9.1, CuO - 9.1Though, an account of some testing and success was posted in skylighter newsletter#62 that used bismuth subcarbonate, read it for yourself: skylighter tips bullitinNow, i can make and mill MgAl, and i have a nice ammount of black copper oxide just begging to be used, so the only thing left to do was find some of one of those damn oxidizers! (Note, some people have had "success" with just CuO/Al, but it doesn't make the poping and crackling, so i wouldn't really call it success at all...) Well, i decided to put some thought into the practicality of synthesizing one of the oxidizers, (havn't decided on a particular one, yet) and what follows are possible routes i have either found off a forum such as roguesci or SMDB, google, or info from my AP Chemistry textbook. Many of these reactions could likely use different ions and still work... Lead reaction routes and info:Cu(C2H3O2)2 + Pb ---> Pb(C2H3O2)2 + CuNa2CO3 + Pb(C2H3O2)2 ---> PbCO3 + NaC2H3O2Now,PbCO3 --heated without O2--> PbO + CO2PbCO3 --heated with O2--> Pb3O4 +CO2!!!!!!IIRC, the direct action of acetic acid on lead is much slower, when done this ^ way the copper precipitates onto the leads surface, then falls off in flakes by its self driving the reaction. I could be wrong, but i think i remember reading that Pb3O4 forms around 450C-480C, melts and decomposes at 500C. Oh, and PbCO3 decomposes at 400C, its melting point.Pb(OH)2 + NaOCl ---> PbO2Pb(OH)2 + H2O2 ---> PbO(at SMDB, i added data from wiki)SMBDOff wikipedia:Wikipedia_on_Red_LeadWikipedia_on_Lead(II)oxide3Pb2CO3(OH)2 + O2 ---> 2Pb3O4 + 3CO2 + 3H2O (lead compound is apparently called lead white, perhaps it is the pigment, though it is no doubt replaced with a less toxic one these days)K2PbO3 + 2Pb(C2H3O2)2 ---> Pb3O4 + KC2H3O2 + HC2H3O2*(Plumbate ion is formed with Pb2+ and a strong base, in this case KOH to make potassium plumbate)HNO3 + Pb ---> NOx + Pb(NO3)2Pb(NO3)2 --heated to decompostion--> PbO(Decomposition is 470C, IIRC)Then there is the good ol nitrite reaction:Pb + KNO3 ---> PbO + KNO2Oh, and before anyone goes to do any roasting, many lead oxides are terrific fluxes in glass, so you may want to consider a non-glass roasting container, same could probably go for the bismuth oxides. Obviously, you could just bubble air or oxygen through molten lead, but it would take quite a bit of time with the very low surface area. Bisumth reaction routes and info:According to my text book,Bi3+ + H2O ---> BiO+ + 2H+if Cl- is added BiOCl, bismuthyl chloride precipitates(Sb3+ acts in a similar fashion if anyone wanted to know)........So, no chloride, go it. That means no HCl, now i havn't checked on H2SO4, but nitric surely dissolves it, quoted:"Reaction with 15M HNO3 mild, =>Bi(NO3)3, NOx"- bismuth_infoNow, im thinking,Bi(NO3)3 + H2O + CO2(g) ---> (BiO)2CO3 + H+ + NO3-Though, it might be too acidic for the bismuth subcarbonate to precipitate... So, so the CO2 might essentially just pass through and not react at all...You could also just decompose it:Bi(NO3)3 --heated to decomposition--> Bi2O3 + NOxThough, im sure few would want to use their precious nirtic acid...Another thought i had would be useful for 2 chemicals if it works:Bi + KNO3 ---> Bi2O3 + KNO2Just replacing lead with bismuth...Then i thought about bismuth and sulfur,Bi + S ---> Bi2S3But i wouldn't count on it being soluble... Perhaps heating this in oxygen would work well... Or reacting it with an acid to drive off H2S, but no one wants to practicly kill themselves, so... i wonder what a strong base would do, perhaps form a sulfide and bismuth hydroxide?Obviously, you could just do it directly, bubbling O2 or air through molten bismuth, and with its relativly low melting point, it could actually be a decent reaction, it would just take quite a bit of time. An interesting source of Bi that i came accross during my searching is... pepto-bismol, bismuth subsalicylate...Both lead and bismuth compounds are supposed to be used in ceramic glazes and i have yet to find lead and bismuth raw compounds in ceramic stores. Lead is everywhere, if you have to ask, your stupid, bismuth can be found as a lead and steel replacement in shotgun shell pellets, fish sinkers sometimes, milling media on sites like UN, solder component, etc...A little more:Wikipedia_on_Bi So... Suggestions? Ideas? Sources? Comments? 1+s?(Oh, and someone should make a pyro desktop backgrounds thread)
Rogue Chemist Posted April 16, 2006 Posted April 16, 2006 Bi(NO3).5H2O+ NaNO2 --> BiONO2 +2HNO3 +NaNO3 +4H2OBiONO3 +Na2CO3 --> (BiO)2CO3 + 2 NaNO3 Ive got a full procedure for the first reaction and an outline for the second. Mannitol is needed in the first reaction.
Givat Posted April 16, 2006 Posted April 16, 2006 There was a topic in UKtocketry on one more oxidizer: sodium thiosulfate. http://www.ukrocketry.co.uk/forum/index.ph...=1535&hl=strobe If any one here got this chem I will be very intrested to know about this comp.
asilentbob Posted April 16, 2006 Author Posted April 16, 2006 Thats pretty interesting rogue, on the product side of the first reaction, did you mean bismuth subnitrite? Or is it subnitrate? Regardless, it interests me, could you perhaps post this procedure and outline or PM them too me? As i understand it, the bismuth subnitrate makes an acidic solution which makes the bismuthyl ion and then you have a medly of nitrate, nitrite (does it go to nitrate stealing an oxygen somewhere?), oh, perhaps, you precipitate the bismuth subnitrite with solubility differences, then after standing in air the nitrite goes to nitrate? I don't know, but im interested! Edit: quest, i think some discussion on how to synth something thiosulfate was at SMDB a while back, so you might search there if you are interested in preparation, if i had some i would try:(... Edit2: -ate/-ite correction
Rogue Chemist Posted April 16, 2006 Posted April 16, 2006 Just an oversight on my part, the pdf was open in a small window so when I thought I was looking at nitrate it was actually nitrite. Whoops The procedure for subnitrAte to subcarbonate is just adding the sodium carbonate solution to a rapidly stirred solution of subnitrate. EDIT: You can get subnitrate at pottery suppliers, expensive at ~20$/lb EDIT2: I cant imagine that using subnitrite vs subnitrate would matter much in the prep of subcarbonate.
asilentbob Posted April 16, 2006 Author Posted April 16, 2006 Thank you, yes, i should be able to make the bismuth nitrate, then subnitrate, then do the double replacement, much more straightforward than i had dreamed! Hmm, in an effort to keep this discussion going for a while, perhaps others could share their thoughts on how they would go about preparing the other compounds? I don't know...
Rogue Chemist Posted April 16, 2006 Posted April 16, 2006 You said pepto bismol is bismuth subsalicylate.....haha...that should react with sodium carbonate the same way as subnitrate to give the subcarbonate
asilentbob Posted April 16, 2006 Author Posted April 16, 2006 Hmm... might be a little pricey... I can only imagine the look on the cashiers face when i try to buy like 10 bottles... hahaha... You would also get sodium salicylate, thats used in whistle instead of benzoate on ocassion isn't it, IIRC told to be slightly more violent... hmm ... I'm going to have to look up the other ingrediants... Edit: 2nd smiley didn't what to work... Edit2: Ingrediants... for the orginal liquid...Bismuth subsalicylate 262 mg / for 15ml tablespoon6mg sodium / tablespoonInactive Ingredients: benzoic acid, flavor, magnesium aluminum silicate, methylcellulose, red 22, red 28, saccharin sodium, salicylic acid, sodium salicylate, sorbic acid, waterIngrediants... for the max strength liquid...Bismuth subsalicylate 525mg / 15ml The chewable tablets and caplets are similar, ie 262mg a pill/chewable, 525mg if max strength, just slightly different inactive ingrediants. Okay, using google calculator, unless i messed up gives 12.4208824 grams of bismuth salicylate per 12oz max strength liquid bottle. Not bad... From a web search on price, one i saw was $4.92, so i would expect something around that... As for purification, i would assume heat to drive off liquid, and rinse powder/residue thats left with some solvent...
Rogue Chemist Posted April 16, 2006 Posted April 16, 2006 I looked up the ingredients, the calcium magnesium silicate in there would complicate things as would the cellulose derivatives. And there is only 1.75g of the bismuth subsalicylate per 100ml.....
asilentbob Posted April 16, 2006 Author Posted April 16, 2006 I wonder what kind of ammounts the inactives are in... Hmm... MSDS? *Searching* Edit: Well, found one MSDS for the liquid, it covers both normal and max strength, but it has absolutely no ammounts besides bismuth salicylate and total salicylate... Grr ... How dare it stand between us and chemistry... Edit2: The .pdfs are here under "Gastrointestinal"MSDS for some PG products
Rogue Chemist Posted April 17, 2006 Posted April 17, 2006 http://www.freepatentsonline.com/4940695.htmlhttp://www.freepatentsonline.com/search.pl...&sort=relevanceThe bottom of the first link contains the percentages for a pepto-bismol ripoff, the second is other potential patents, hopefully one is for pepto bismol, I have studying to do so I cannot go through them now.
asilentbob Posted April 18, 2006 Author Posted April 18, 2006 I only did a real quick look over of some of the more promising sounding patents, and some did contain bismuth salicylate, but, IIRC they all (except the one you mentioned) contained some other substance that was also an active ingrediant, but i may have missed a few, so... I'm going to look for some pepto-bismol or similar around the house right now, if i can find some ill take mabey 50mls and drive off the water... well... i guess i would have to drive off alot more to get a significant ammount if it is normal strength... If i can't find any ill go back to picking a formulation and making some red stars...
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