The topic of this note has been brewing for a long time. And although at the request of channel readers , I just wanted to write about safe work with hydrogen peroxide, but in the end, for reasons I don’t understand (yes!) I ended up with another longread. A mixture of popsci, rocket fuel, "coronavirus disinfection" and permanganometric titration. How correctly store hydrogen peroxide, what protective equipment to use during work and how to escape in case of poisoning - we are looking under the cut.
ps the beetle from the picture is actually called "scorer". And he was also somewhere lost among the chemicals 🙂
Dedicated to the "Children of Peroxide"...
Our brother fell in love with hydrogen peroxide, oh, how he fell in love. I think about this every time I see a question like “the bottle of hydrogen peroxide is inflated. what to do?" By the way, I meet quite often 🙂
Not surprisingly, in the post-Soviet space, hydrogen peroxide (3% solution) is one of the favorite “folk” antiseptics. And pour on the wound, and disinfect the water, and destroy the coronavirus (recently). But despite the seeming simplicity and accessibility, the reagent is rather ambiguous, which I will discuss further.
Walking along the biological "tops" ...
Now everything with the prefix eco- is fashionable: eco-friendly products, eco-friendly shampoos, eco-friendly things. As I understand it, people want to use these adjectives to distinguish biogenic things (that is, those found in living organisms initially) from purely synthetic things (“hard chemistry”). Therefore, at first, a small introduction, which I hope will emphasize the environmental friendliness of hydrogen peroxide and add confidence to it among the masses 🙂
So what is hydrogen peroxide? This protozoa peroxide compound, which has in its composition two oxygen atoms at once (they are connected by a bond -OO-). Where there is such a type of connection, there is instability for you, there is atomic oxygen, and strong oxidizing properties, and everything. But despite the severity of atomic oxygen, hydrogen peroxide is present in many living organisms, incl. and in man. It is formed in micro quantities during the course of complex biochemical processes and oxidizes proteins, membrane lipids and even DNA (due to the resulting peroxide radicals). Our body in the process of evolution has learned to deal with peroxide quite effectively. He does this with the help of the enzyme superoxide dismutase, which destroys peroxide compounds to oxygen and hydrogen peroxide, plus the enzyme which peroxide for one or two will convert into oxygen and water.
Enzymes are beautiful in XNUMXD models
Hid under the spoiler. I like to look at them, but suddenly someone doesn’t like it ...
By the way, it is thanks to the action of catalase, which is present in the tissues of our body, that the blood “boils” during the treatment of wounds (there will be a separate remark about wounds below).
Hydrogen peroxide also has an important “protective function” inside us. Many living organisms have such an interesting organelle (the structure necessary for the functioning of a living cell) as . These structures are lipid vesicles inside which there is a crystal-like core, consisting of biological tubular "". Various biochemical processes take place inside the nucleus, as a result of which hydrogen peroxide is formed from atmospheric oxygen and complex organic compounds of a lipid nature!
But the most interesting thing here is what this peroxide is then used for. For example, in the cells of the liver and kidneys, the resulting H2O2 goes to destroy and neutralize the toxins entering the blood. Acetaldehyde, which is formed during the metabolism of alcoholic beverages () - this is also the merit of our little tireless workers of peroxisomes, and the "mother" of hydrogen peroxide.
So that everything does not seem so rosy with peroxides, suddenly Let me remind you about the mechanism of action of radiation on living tissue. Molecules of biological tissues absorb radiation energy and are ionized, i.e. go into a state conducive to the formation of new compounds (most often completely unnecessary within the body). Water is most often and most easily ionized, it occurs . In the presence of oxygen, under the influence of ionizing radiation, various free radicals (OH- and others like them) and peroxide compounds (H2O2 in particular) arise.
The resulting peroxides actively interact with the chemical compounds of the body. Although if we take as an example the superoxide anion (O2-) sometimes formed during radiolysis, then it is worth saying that this ion is also formed under normal conditions, in an absolutely healthy organism, without free radicals и our immunity could not destroy bacterial infections. Those. completely without these in any way it is impossible - they accompany biogenic oxidation reactions. The problem arises when there are too many of them.
It is to combat “too much” peroxide compounds that man invented such things as antioxidants. They inhibit the oxidation of complex organics with the formation of peroxides, etc. free radicals and thereby reduce the level of .
Oxidative stress is the process of cell damage due to oxidation (= too many free radicals in the body)
Although, in fact, these compounds do not give anything new, to what is already available, i.e. "internal antioxidants" - superoxide dismutase and catalase. And in general, if used improperly, synthetic antioxidants will not only not help, but this very oxidative stress will also increase.
Remarque about “peroxide and wounds”. Although hydrogen peroxide is a regular fixture in home (and factory) first aid kits, there is evidence that H2O2 use interferes with wound healing and causes scarring because hydrogen peroxide . Only very low concentrations give a positive effect (0,03% solution, which means you need to dilute 3% pharmacy 100 times), and only with a single application. By the way, “coronavirus ready” 0,5% solution too . So, as they say, trust but verify.
Hydrogen peroxide in everyday life and "against coronavirus"
If hydrogen peroxide can even turn ethanol into acetaldehyde in the liver, then it would be strange not to use these wonderful oxidizing properties in everyday life. They are used in the following proportions:
Half of all hydrogen peroxide produced by the chemical industry is used to bleach pulp and various types of paper. The second place (20%) in demand is occupied by the production of various bleaches based on inorganic peroxides (sodium percarbonate, sodium perborate, etc., etc.). These peroxides (often in combination with to reduce the bleaching temperature, tk. peroxosalts do not work at temperatures below 60 degrees) are used in all sorts of “Persol”, etc. (more details can be found ). Then comes the bleaching of fabrics and fibers (15%) and water purification (10%) with a small margin. And finally, the share that remains is equally divided between purely chemical things and the use of hydrogen peroxide for medical purposes. I will dwell on the latter in more detail, because most likely the coronavirus pandemic will change the numbers on the diagram (if it has not already changed).
Hydrogen peroxide is actively used to sterilize various surfaces (including surgical instruments) and recently also in the form of steam (the so-called. - vaporized hydrogen peroxide) for sterilization of premises. The figure below is an example of such a peroxide vapor generator. A very promising direction, which has not yet reached domestic hospitals ...
In general, peroxide shows high disinfection efficiency for a wide range of viruses, bacteria, yeasts, and bacterial spores. It should be noted that for complex microorganisms, due to the presence in them of enzymes that decompose peroxide (the so-called peroxidases, of which catalase is a special case), tolerance (~stability) can be observed. This is especially true for solutions with concentrations below 1%. But against 3%, and even more so 6–10%, nothing can resist yet, neither a virus nor a bacterial spore.
In fact, along with ethyl and isopropyl alcohol and sodium hypochlorite, hydrogen peroxide is on the list of “vital” emergency antiseptics for disinfecting surfaces from COVID-19. Although not only from COVID-19. At the beginning of the whole coronavirus bacchanalia, we are with readers actively used when choosing antiseptics recommendations from . The recommendations apply to coronaviruses in general, and COVID-19 in particular. So I recommend downloading and printing the article (for those interested in this issue).
An important sign for a young disinfectologist
During the time that has passed since the beginning of the epidemic, nothing has changed in terms of working concentrations. But it has changed, for example, in relation to the forms in which hydrogen peroxide can be used. Here I would like to immediately recall the document with compositions recommended for disinfection. I was traditionally interested in wipes on this list (traditionally, because I like disinfectant wipes, hypochlorite me and 100% satisfied with them. In this case, I was interested in such an American product as Oxivir Wipes (or its equivalent Oxivir 1 Wipes) from Diversey Inc.
There are few active ingredients listed there:
Hydrogen Peroxide 0.5%
Simple and tasteful. But for those who want to repeat such a composition and soak their custom wet wipes, I will say that in addition to hydrogen peroxide, the impregnating solution also contains:
Phosphoric acid (phosphoric acid - stabilizer) 1-5%
2-Hydroxybenzoic Acid (salicylic acid) 0,1-1,5%
Why all these “impurities” will become clear when you read to the section on stability.
In addition to the composition, I would also like to recall what it says to the mentioned Oxivir. Nothing fundamentally new (relative to the first table), but I liked the spectrum of viruses that can be disinfected.
What viruses peroxide can overcome
And I wouldn’t be myself if I hadn’t once again reminded about the exposure during processing. As before (= as always) it is recommended to do so that when wiped with wet wipes, all hard, non-porous surfaces remained visibly wet for at least 30 seconds (or better than a minute!) to decontaminate everything and everyone (and this your COVID-19 too).
Hydrogen peroxide as a chemical
We've walked around the bush, now it's time to write about hydrogen peroxide, from the point of view of a chemist. Fortunately, it is this question (and not how the peroxisome looks) that most often interests an inexperienced user who decides to use H2O2 for his own purposes. Let's start with the XNUMXD structure (as I see it):
How the girl Sasha sees the structure, who is afraid that the peroxide might explode (more on that below)
"Running cockerel bottom view"
Pure peroxide is a clear (bluish for high concentrations) liquid. The density of dilute solutions is close to the density of water (1 g/cm3), concentrated solutions are denser (35% - 1,13 g/cm3...70% - 1,29 g/cm3, etc.). By density (in the presence of hydrometers), you can accurately determine the concentration of your solution (information from ).
Domestic technical hydrogen peroxide can be of three grades: A = concentration 30–40%, B = 50–52%, C = 58–60%. Often there is such a name as “perhydrol” (there was once even the expression “perhydrol blonde”). In fact, it’s still the same “brand A”, i.e. a solution of hydrogen peroxide with a concentration of about 30%.
Remark about whitening. Since we remembered the blondes, it can be noted that diluted hydrogen peroxide (2–10%) and ammonia were used as a bleaching composition for “operating” hair. Now this is rarely practiced. But there is peroxide teeth whitening. By the way, whitening of the skin of the hands after contact with peroxide is also a kind of “operated hydrolysis” caused by thousands , i.e. blockages of capillaries formed during the decomposition of peroxide with oxygen bubbles.
Medical technical peroxide becomes when demineralized water is added to peroxide with a concentration of 59–60%, diluting the concentrate to the desired level (3% in domestic open spaces, 6% in the USA).
In addition to density, an important parameter is the pH level. Hydrogen peroxide is a weak acid. The picture below shows the dependence of the pH of a hydrogen peroxide solution on mass concentration:
The more dilute the solution, the closer its pH is to the pH of water. The minimum pH (=most acidic) falls at concentrations of 55–65% (grade B according to the domestic classification).
Although it is reluctant to note here that pH cannot be used to quantify concentration for several reasons. First, almost all modern peroxide is obtained by oxidizing anthraquinones. This process produces acidic by-products that can end up in the finished peroxide. Those. The pH may differ from that shown in the table above depending on the purity of the H2O2. Ultra-pure peroxide (for example, which goes for rocket fuel and which I will talk about separately) does not contain impurities. Second, acidic stabilizers are often added to commercial hydrogen peroxide (peroxide is more stable at low pH), which will "lubricate" the readings. And thirdly, chelate stabilizers (for binding metal impurities, more about them below) can also be alkaline or acidic and affect the pH of the final solution.
The best way to determine concentration is (). The technique is exactly the same, but only all the reagents necessary for the test are very easily available. We need concentrated sulfuric acid (battery electrolyte) and ordinary potassium permanganate. As B. Gates once shouted “640 kb of memory is enough for everyone!”, I will also exclaim now “Everyone can titrate peroxide!” :). Despite the fact that intuition tells me that if you buy hydrogen peroxide in a pharmacy and do not store it for decades, then concentration fluctuations are unlikely to exceed ± 1%, I will nevertheless outline the verification method, since the reagents are available and the algorithm is quite simple.
Checking commercial hydrogen peroxide for lice
As you might guess, we will check using titration. The technique makes it possible to accurately determine concentrations from 0,25 to 50%.
The verification algorithm is as follows:
1. Prepare a 0,1N solution of potassium permanganate. To do this, dissolve 3,3 grams of potassium permanganate in 1 liter of water. The solution is heated to a boil and boil for 15 minutes.
2. We select the required volume of the studied peroxide (depending on the estimated concentration, i.e. if you had 3%, expecting that it suddenly became 50% is stupid):
We transfer the selected volume to the bottle and weigh it on the scales (do not forget to press the Tare button so as not to take into account the weight of the bottle itself)
3. Pour our sample into a 250 ml volumetric flask (or baby bottle with volume marking) and top up to the mark (“250”) with distilled water. We mix.
4. Pour 500 ml of distilled water into a 250 ml conical flask (=”half-liter jar”), add 10 ml of concentrated sulfuric acid and 25 ml of our solution from item 3
5. Drop by drop (preferably from a pipette on which the volume is marked) a solution of 0,1N potassium permanganate into our half-liter jar from item 4. Dropped - mixed, dripped - mixed. And so we continue until the clear solution acquires a slightly pinkish tint. As a result of the reaction, peroxide decomposes with the formation of oxygen and water, and manganese (VI) in potassium permanganate is reduced to manganese (II).
5H2O2 + 2KMnO4 + 4H2SO4 = 2KHSO4 + 2MnSO4 + 5O2 + 8H2O
6. We consider the concentration of our peroxide: C H2O2 (wt.%) \u0,1d [Volume of potassium permanganate solution in ml * 0,01701 * 1000 * 2] / [sample weight in grams, from paragraph XNUMX] PROFIT!!!
Free discussions on the topic of storage stability
Hydrogen peroxide is considered an unstable compound, which is prone to spontaneous decomposition. The rate of decomposition increases with increasing temperature, concentration and pH. Those. Generally speaking, the rule is:
…cold, dilute, acidic solutions show the best stability…
Decomposition is facilitated by: an increase in temperature (an increase in speed of 2,2 times for every 10 degrees Celsius, and at a temperature of about 150 degrees, concentrates in general avalanche-like decompose with an explosion), increase in pH (especially at pH > 6–8)
Remark about glass: only acidified peroxide can be stored in glass bottles, because. glass tends to give an alkaline environment when in contact with clean water, which means it will contribute to accelerated decomposition.
Affects the rate of decomposition and the presence of impurities (especially transition metals such as copper, manganese, iron, silver, platinum), UV exposure. Most often, the main complex cause is the increase in pH and the presence of impurities. On average, at 30% hydrogen peroxide loses approximately .
To remove impurities, ultrafine filtration (exclusion of particles) or chelates (complexing agents) that bind metal ions are used. Can be used as chelates , colloidal or sodium pyrophosphate (25–250 mg/l), organophosphonates, nitrates (+pH regulators and corrosion inhibitors), phosphoric acid (+pH regulator), sodium silicate (stabilizer).
The influence of ultraviolet on the decomposition rate is not as pronounced as for pH or temperature, but it also takes place (see picture):
It can be seen that the molecular extinction coefficient increases with decreasing ultraviolet wavelength.
The molar extinction coefficient is a measure of how strongly a chemical absorbs light at a given wavelength.
By the way, this decomposition process initiated by photons is called photolysis:
Photolysis (aka photodissociation and photodecomposition) is a chemical reaction in which a chemical substance (inorganic or organic) is split by photons after they interact with a target molecule. Any photon with sufficient energy (higher than the dissociation energy of the target bond) can cause decomposition. An effect similar to the effect of ultraviolet can give also X-rays and γ-rays.
What can be said in general. And the fact that peroxide should be stored in an opaque container, and preferably in brown glass bottles that block excess light (despite the fact that “absorbs” ! = “immediately decomposes”). You shouldn’t keep a bottle of peroxide next to the X-ray machine either 🙂 Well, from this one (UR 203Ex (?):
… from "Peroxide (and your loved one, to be honest) should also be kept away.
It is important that in addition to being opaque, the container/bottle must be made of "peroxide resistant" materials like stainless steel or glass (well, some plastics and aluminum alloys). A sign may be useful for orientation (it will be useful, among other things, for doctors who are going to process their equipment):
The label legend is as follows: A - excellent compatibility, B - good compatibility, little impact (microcorrosion or discoloration), C - poor compatibility (not recommended for long-term use, loss of strength, etc.), D - no compatibility (= cannot be used). A dash means “no information available”. Numerical indices: 1 - satisfactory at 22°C, 2 - satisfactory at 48°C, 3 - satisfactory, when used in gaskets and seals.
Hydrogen Peroxide Safety
It is likely clear to anyone who has read up to this section that peroxide is a strong oxidizing agent, which means that it is essential to store it away from flammable / combustible substances and reducing agents. H2O2, both pure and diluted, can form in contact with organic compounds. Given all of the above, you can write like this
Hydrogen peroxide is incompatible with combustible materials, any combustible liquids and metals and their salts (in decreasing order of catalytic action) - osmium, palladium, platinum, iridium, gold, silver, manganese, cobalt, copper, lead
Speaking about metal decomposition catalysts, it is impossible not to say separately about . It is not only the densest metal on Earth, it is also the best weapon in the world for the decomposition of hydrogen peroxide.
The effect of accelerating the decomposition of hydrogen peroxide for this metal is observed in quantities that not even every analytical method can detect - in order to very effectively (x3-x5 times relative to peroxide without a catalyst) decompose peroxide into oxygen and water, you need only 1 gram of osmium per 1000 tons of peroxide hydrogen.
Remark about the "explosive nature": (I immediately wanted to write “I am peroxide”, but was too shy). In the case of hydrogen peroxide, the spherical girl Sasha, who has to work with this peroxide, is most often afraid of an explosion. And in principle, there is common sense in Alexandra's fears. After all, peroxide can explode for two reasons. Firstly, from the fact that the gradual decomposition of H2O2, the release and accumulation of oxygen will occur in a sealed container. The pressure inside the container will build and build and eventually BOOM! Secondly, there is a possibility that when hydrogen peroxide comes into contact with some substances, unstable peroxide compounds will form, which can detonate from impact, heating, etc. In a classy five-volume book so much has been said about this that I even decided to hide it under a spoiler. Information applicable to concentrated hydrogen peroxide >= 30% and <50%:
Absolute incompatibility
explodes on contact with: alcohols + sulfuric acid, acetal + acetic acid + heat, acetic acid + N-heterocycles (above 50 °C), aromatic hydrocarbons + trifluoroacetic acid, azelaic acid + sulfuric acid (about 45 °C), tert-butanol + sulfuric acid , carboxylic acids (formic, acetic, tartaric), diphenyl diselenide (above 53 °C), 2-ethoxyethanol + polyacrylamide gel + toluene + heating, gallium + hydrochloric acid, iron (II) sulfate + nitric acid + carboxymethyl cellulose, nitric acid + ketones (2-butanone, 3-pentanone, cyclopentanone, cyclohexanone), nitrogenous bases (ammonia, hydrazine hydrate, dimethylhydrazine), organic compounds (glycerol, acetic acid, ethanol, aniline, quinoline, cellulose, coal dust), organic materials + sulfuric acid (especially in confined spaces), water + oxygen-containing organics (acetaldehyde, acetic acid, acetone, ethanol, formaldehyde, formic acid, methanol, propanol, propanal), vinyl acetate, alcohols + tin chloride, phosphorus (V) oxide, phosphorus, nitric acid , antimonite, arsenic trisulfide, chlorine + potassium hydroxide + chlorosulfonic acid, copper sulfide, iron (II) sulfide, formic acid + organic contaminants, hydrogen selenide, lead di- and monoxide, lead (II) sulfide, manganese dioxide, mercury oxide ( I), molybdenum disulfide, sodium iodate, mercury (II) oxide + nitric acid, diethyl ether, ethyl acetate, thiourea + acetic acid
lights up on contact with: furfuryl alcohol, powdered metals (magnesium, zinc, iron, nickel), sawdust
violent reaction from: aluminum isopropoxide + heavy metal salts, charcoal, coal, lithium tetrahydroaluminate, alkali metals, methanol + phosphoric acid, unsaturated organic compounds, tin (II) chloride, cobalt oxide, iron oxide, lead hydroxide, nickel oxide
In principle, if you treat concentrated peroxide with respect and do not combine it with the substances mentioned above, then you can work comfortably for years and not be afraid of anything. But God saves the safe, so we smoothly move on to personal protective equipment.
PPE and aftermath
The idea of writing an article arose when I decided to make a note in dedicated to the issues of safe work with concentrated H2O2 solutions. Fortunately, many readers bought cans of perhydrol for themselves (in case “there is nothing in the pharmacy” / “we won’t get to the pharmacy”) and even managed to get chemical burns in the heat of the moment. Therefore, most of what is written below (and above) refers mainly to solutions with a concentration above 6%. The higher the concentration, the more relevant the presence of PPE.
For safe work, as personal protective equipment, all you need are gloves made of polyvinyl chloride / butyl rubber, polyethylene, polyester and other plastics to protect the skin of the hands, goggles or protective masks made of transparent polymeric materials to protect the eyes. If aerosols are formed, we add a respirator with aerosol protection to the kit (or rather, an ABEK carbon filter cartridge with P3 protection). When working with weak solutions (up to 6%), gloves are sufficient.
I will dwell on the “striking effects” in more detail. Hydrogen peroxide is a moderately hazardous substance that causes chemical burns if it comes into contact with the skin and eyes. Harmful by inhalation and if swallowed. See the picture from SDS ("Oxidizing" - "Corroding" - "Irritant"):
In order not to beat around the bush, I will immediately write about what to do if hydrogen peroxide with a concentration of> 6% came into contact with a certain spherical person without personal protective equipment.
RџSЂRё skin contact - Wipe with a dry cloth, or swab moistened with alcohol. Then it is necessary to wash the damaged skin with a plentiful stream of water for 10 minutes.
RџSЂRё eye contact - immediately rinse eyes wide open, as well as under the eyelids with a weak stream of water (or a 2% solution of baking soda) for at least 15 minutes. Contact an ophthalmologist.
If swallowed - drink plenty of water (= plain water in liters), activated charcoal (1 tablet per 10 kg of body weight), saline laxative (magnesium sulfate). Do not induce vomiting (= gastric lavage ONLY by a doctor, using a probe, and no more familiar "two fingers in the mouth"). Do not give anything by mouth to an unconscious person.
At all swallowing is especially dangerous, since during decomposition a large amount of gas is formed in the stomach (10 times the volume of a 3% solution), which leads to bloating and compression of the internal organs. That's what activated charcoal is for...
If everything is more or less clear with the treatment of the consequences for the body, then it’s worth saying a few more words about the disposal of excess / old / spilled hydrogen peroxide due to inexperience.
... hydrogen peroxide is disposed of either a) by diluting with water and draining into the sewer, or b) by decomposition using catalysts (sodium pyrosulfite, etc.), or c) by heating decomposition (including boiling)
How it all looks like in an example. For example, in the laboratory I accidentally spilled a liter of 30% hydrogen peroxide. I don’t wipe anything, but I fill the liquid with a mixture of equal amounts (1: 1: 1) +sand+ (=”bentonite tray filler”). Then I moisten this mixture with water until a slurry is formed, collect the slurry with a scoop into a container, and transfer it to a bucket of water (two-thirds are filled). And already in a bucket of water, I gradually add a solution of sodium pyrosulfite with a 20% excess. To neutralize the whole thing by reaction:
Na2S2O5 + 2H2O2 = Na2SO4 + H2SO4 + H2O
If you comply with the conditions of the problem (a liter of 30% solution), then it turns out that 838 grams of pyrosulfite are needed for neutralization (a kilogram of salt comes out in excess). The solubility of this substance in water is ~ 650 g/l, i.e. about one and a half liters of concentrated solution will be needed. The moral is this - either do not spill perhydrol on the floor, or dilute it harder, otherwise you won’t get neutralizers 🙂
When looking for possible replacements for pyrosulfite, Captain Obviousness recommends using those reagents that, when reacted with hydrogen peroxide, do not produce horrific volumes of gas. It can be, for example, iron (II) sulfate. It is sold in hardware stores and even in Belarus. To neutralize H2O2, a solution acidified with sulfuric acid is required:
2FeSO4 + H2O2 + H2SO4 = Fe2(SO4)3 + 2H2O
You can also use potassium iodide (also acidified with sulfuric acid):
2KI + H2O2 + H2SO4 = I2 + 2H2O + K2SO4
Let me remind you that all reasoning is based on introductory tasks (30% solution), if you spilled peroxide with lower concentrations (3–7%), then potassium permanganate acidified with sulfuric acid can also be used. Even if oxygen is released there, then due to low concentrations, it will not be able to “do things” with all its desire.
About the beetle
And I have not forgotten about him, my dear. It will be as a reward to those who have read my next longread. I don’t know if the respected Alexei JetHackers Statsenko aka thought about it 30 years ago about my jetpacks, but I definitely had some such thoughts. Especially when on a VHS cassette I had a chance to watch (and even review) a bright Disney fairy tale movie “" (in original Rocketeer).
The link here is the following. As I wrote earlier, hydrogen peroxide of high concentrations (like domestic brand B) with a high degree of purification (note - the so-called high-test peroxide or ) can be used as fuel in rockets (and torpedoes). Moreover, it can be used both as an oxidizer in two-component engines (for example, as a replacement for liquid oxygen), and as a so-called. monopropellants. In the latter case, H2O2 is pumped into the “combustion chamber”, where it decomposes on a metal catalyst (any of the metals mentioned earlier in the article, for example, silver or platinum) and under pressure, in the form of steam with a temperature of about 600 ° C, exits the nozzle, creating traction.
The most interesting thing is that the same internal device (“combustion chamber”, nozzles, etc.) has a small beetle from the subfamily of ground beetles inside its body. it is officially called, but its internal structure (= the picture at the beginning of the article) reminds me of the unit from the 1991 film mentioned above 🙂
The bug is called a bombardier because it is able to more or less accurately shoot from the glands in the back of the abdomen with a boiling liquid with an unpleasant odor.
The ejection temperature can reach 100 degrees Celsius, and the ejection speed is 10 m/s. One shot lasts from 8 to 17 ms, and consists of 4–9 immediately following each other pulses. In order not to have to rewind to the beginning, I will repeat the picture here (it seems to be taken from a magazine from the article of the same name).
The beetle produces within itself two “rocket fuel components” (i.e. it is still not “mono-propellant”). Strong reducing agent (used previously as a developer in photography). And a strong oxidizing agent is hydrogen peroxide. When threatened, the beetle contracts muscles that push the two reagents through valve tubes into a mixing chamber containing water and a mixture of peroxide-degrading enzymes (peroxidases). In combination, the reactants give a violent exothermic reaction, the liquid boils and turns into a gas (= “annihilation”). In general, the beetle scalds a potential enemy with a stream of boiling water (but obviously not enough for the first space thrust). But ... At least the beetle can be considered an illustration for the section Hydrogen Peroxide Safety. The moral is the following:
%USERNAME%, don't be like a bombardier beetle, don't mix peroxide with a reducing agent without understanding! 🙂
Addendum aboutт : "Looks like the terrestrial bombardier beetle is the inspiration for the plasma beetle from Starship Troopers. Here he just has enough momentum (not thrust!) To develop the first cosmic speed, the mechanism was developed during evolution and was used to throw spores into orbit in order to expand the range, and also came in handy as a weapon against clumsy enemy cruisers "
Well, he talked about the beetle and figured out the peroxide. Let's stop there for now.
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Next in line for consideration are sodium dichloroisocyanurate and “chlorine tablets.”
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And I almost forgot, a warning for irresponsible comrades 🙂
Disclaimer: All information contained in the article is provided for informational purposes only and is not a direct call to action. You carry out all manipulations with chemical reagents and equipment at your own peril and risk. The author does not bear any responsibility for careless handling of aggressive solutions, illiteracy, lack of basic school knowledge, etc. If you do not feel confident in understanding what is written, ask a relative / friend / acquaintance who has a specialized education to control your actions. And be sure to use PPE with the highest possible safety precautions.
Source: habr.com