anybody selling P benzoquinone (non lab)

[wtburton]

I tried to get some from the manufacturer but I am not a lab. I will have to see if I can get my school to have it shipped to them. I will also try to make some from the alcohol and hydrogen peroxide method with regular hydroquinone.

 

[Nicholas Lindan]

Try, oh, Amazon,, B&H, Adorama, ebay ....

It's pretty nasty stuff - out of curiosity, what's the intended use?

 

[wtburton]

Try, oh, Amazon,, B&H, Adorama, ebay ....

It's pretty nasty stuff - out of curiosity, what's the intended use?

I need it for this bleach

 

[Nicholas Lindan]

I take it you are experimenting with holography?

 

[mohmad khatab]

And why do you want this particular bleach?
There are other types of bleach that are easier to prepare.
I don't know what process you plan in the end,
But I think there are many alternatives

 

[wtburton]

And why do you want this particular bleach?

Its mentioned as the best holographic bleach for reflection holograms out there. Others seem a lot more dangerous, like mercuric chloride? I dont know any other alternatives for reflection hologram processing

 

[wtburton]

I take it you are experimenting with holography?

Yeah, I am going to try to make RGB reflection holograms on Lippmann plates. I have had two from @amphetadreamer / jonhilty.com that I will be using.

The laser I am using is https://www.laserlands.net/diode-laser-module/rgb-combined-white-laser-module/rgbopt.html

A few people have said this diode laser will not work, but I have checked with the guy who runs Litiholo and he affirmed that the photopolymer they use is comparable to Lippmann-- and they sell RGB diode lasers for color hologram use also, and it worked. I am pretty sure this will work too.

I am using a microscope lens as my diverging lens, I 3D printed a mount to hold the lens directly in line with the beam. I have not yet tried to power the beam as its way too powerful un-diverged. I need to make a metal cover to cover up the beam portion.

My math teacher helped me put the formula in a sheet, and I was able to figure out the erg/s*cm^2 of the laser to cover an 8x10 plate. Its not that much, about 2? the book I have, holography handbook, states that around 55-100 are needed for lower res plates, up too 400-100 and going into the thousands. That puts me at a minute for the best speed, which the Lippmann are probably not. I am still not certain if this is even right at all.

From what I understand, most lasers used for holography are sub 100mw. This has a combined mw of 1010 total, (R & G 180mw, B 650mw) (not sure if blue being so much higher is gonna affect things, do the low sensitivity of blue counter it? or should I TTL the blue off? (im not even sure how to do that)) Anyways, I think it should be quite a lot faster than normal holography lasers, so I am going to bracket on the first plate from half a second to around 20 min.

Anyways, I plan to develop in this

stop it, and then bleach in this

https://sci-hub.hkvisa.net/10.1364/AO.23.000934

From what I understand, its one of the best recipes.

 

[wtburton]

I have ferricyanide bleach, but from what I read I dont think it works that well

 

[wtburton]

Since I could not order from Thermo Scientific, I found photographers formulary sells what I need and will get it to me as long as I do that DEA form. 10 measly grams is enough for 5 plates. The amount of potassium bromide used is also outrageous for a one time use bleach.

In the meantime, I am going to try to synthesize it with hydrogen peroxide and alcohol with hydroquinone. Any suggestions on how?
I see it done with bromate, sulfuric acid or potassium dichromate, and hydroquinone. I dont have the first two ingredients tho.

 

[Lachlan Young]

You are aware of the safety hazards with PBQ and have access to appropriate measures to deal with them?

 

[mohmad khatab]

Its mentioned as the best holographic bleach for reflection holograms out there. Others seem a lot more dangerous, like mercuric chloride? I dont know any other alternatives for reflection hologram processing

I would be lying if I pretended I knew what you're saying.
I'm sorry, I'm ignorant of what you're saying and I don't understand what that process is.
If you have the time and give me an overview of this process, I will be very grateful to you.
But I always use copper bleach.
Trust me, it's cheap, safe, very effective and very accurate, but it's kinda slow, it needs eight to 12 12

 

[wtburton]

You are aware of the safety hazards with PBQ and have access to appropriate measures to deal with them?

Yeah I figured that out and now I am just going to use EDTA bleach. I hope it works.

As for my laser, its not as good as I hoped. I powered it on today and I can only use about 1/8th of the total size because the lasers only combine over a small portion. And that portion is also overwhelmingly blue! I will have to keep blue off for 2/3ish of the time since its 3.5 times more powerful. Not a huge deal. Green has terrible spread, why is it oriented horizontal?

final result will probably be very messy, I should be able to rid most of the major lens spots, but there isnt anything I can do about the interference patterns? maybe a pinhole?

 

[Nikola Dulgiarov]

Since I could not order from Thermo Scientific, I found photographers formulary sells what I need and will get it to me as long as I do that DEA form. 10 measly grams is enough for 5 plates. The amount of potassium bromide used is also outrageous for a one time use bleach.

In the meantime, I am going to try to synthesize it with hydrogen peroxide and alcohol with hydroquinone. Any suggestions on how?
I see it done with bromate, sulfuric acid or potassium dichromate, and hydroquinone. I dont have the first two ingredients tho.

Keep in mind that quinone and its preparation are dangerous not only because of the caustic nature of the reagents, but the relatively high vapor pressure of PBQ and its relatively higher toxicity. I wouldn't attempt synthesizing it without proper equipment and safety gear.
If you go that route, I suggest you prepare it in situ rather than trying to isolate and purify the product. This could possibly be done by mixing HQ (MW 110g/mol, PBQ MW 108g/mol) and citric acid and adding hydrogen peroxide in 10-40% molar excess to the HQ (3% H2O2 is about 0.8-0.9 mol/L). The reaction should progress at room temp, but it might require gentle heating (up to 50C, otherwise you risk volatilizing and steam distilling the benzoquinone out of solution). Typically the reaction is carried out in acid medium,so the citric acid satisfies that requirement. Do not add the KBr before the reaction is complete or you will produce molecular bromine! That said, halogen salts are used as catalysts in the oxidation of aromatics, so a small amount (5-10% of the HQ mass) of the bromide could be added to facilitate the conversion. Expect a small amount of oxidized junk, the reaction goes through an intermediate quinhydrone, which might precipitate as green-brown needles.

 

[wtburton]

Keep in mind that quinone and its preparation are dangerous not only because of the caustic nature of the reagents, but the relatively high vapor pressure of PBQ and its relatively higher toxicity. I wouldn't attempt synthesizing it without proper equipment and safety gear.
If you go that route, I suggest you prepare it in situ rather than trying to isolate and purify the product. This could possibly be done by mixing HQ (MW 110g/mol, PBQ MW 108g/mol) and citric acid and adding hydrogen peroxide in 10-40% molar excess to the HQ (3% H2O2 is about 0.8-0.9 mol/L). The reaction should progress at room temp, but it might require gentle heating (up to 50C, otherwise you risk volatilizing and steam distilling the benzoquinone out of solution). Typically the reaction is carried out in acid medium,so the citric acid satisfies that requirement. Do not add the KBr before the reaction is complete or you will produce molecular bromine! That said, halogen salts are used as catalysts in the oxidation of aromatics, so a small amount (5-10% of the HQ mass) of the bromide could be added to facilitate the conversion. Expect a small amount of oxidized junk, the reaction goes through an intermediate quinhydrone, which might precipitate as green-brown needles.

Thank you for the explanation! When you say mixing the ingredients and you listed PBQ, did your mean KBr? I do not have any PBQ.
For now I was going to just use EDTA bleach, I might return to PBQ later

 

[Nicholas Lindan]

Green has terrible spread, why is it oriented horizontal?

The green channel may be a NIR laser with a KDP (potassium dihydrogen phosphate) crystal that doubles the frequency, turning a 1064nm beam into a 532nm beam. This is the approach taken in green laser pointers. There is a lot of really horrid Chinese KDP out there, expect all sorts of strange distortions to the beam shape. Polishing is a major manufacturing cost for KDP crystals - however even a roughly polished and non-parallel KDP crystal will frequency double. The doubled beam requires a filter to remove the remnants of the original NIR beam, and many cheap green lasers employ ineffective IR filters.