Sciencemadness Discussion Board - alternative to lead iodide

alternative to lead iodide

Little_Ghost_again - 2-11-2014 at 15:35

Hi
Are there alternatives to lead iodide? I am looking for something of similar colour etc that isnt considered poisonous or an irritant.
I like the gold flake look and have a use for it based upon how it looks. Obviously yes gold flake fits exactly but price is a bit steep even for gold leaf.

Metacelsus - 2-11-2014 at 15:43

Alkyl xanthic disulfides and thioanhydrides have a beautiful golden-yellow color, and are also insoluble in water (but soluble in other solvents). If you can get carbon disulfide, they are easy to make.

They do not, however, have the thermochromic effects of lead iodide; they just melt.

What exactly are you going to use this stuff for? There are many possible yellow pigments.

[Edited on 2-11-2014 by Cheddite Cheese]

j_sum1 - 2-11-2014 at 15:52

I take it you want something a bright yellow. What is it for?
Gold leaf need not be that expensive. Smaller quantities are available at roughly proportionate prices. Often shipping is free from Thailand.
Or you could go for imitation gold leaf. If you don't like purchasing online (and I understand that you have limitations with that), you could always go to an art supplier for either of these.

You could also do some electrolysis of copper sulfate and get some copper powder. If you wanted a lighter or more gold kind of colour then maybe attack something brass with a file.

And I am sure there are some suitably yellow salts around but none off the top of my head that would guarantee are not irritating.

Like I said, it depends on what you want it for.

Little_Ghost_again - 2-11-2014 at 16:01

Its for adding to soap for a flake or speckled effect

UnintentionalChaos - 2-11-2014 at 16:08

I think you are looking for "cosmetic mica."

Something exactly like this: http://www.brambleberry.com/Gold-Sparkle-Mica-P3063.aspx

With respect to jsum_1's post, electrolytic (and other) copper powder is a dull reddish-brown material and wholly unsuitable for soap.

[Edited on 11-3-14 by UnintentionalChaos]

j_sum1 - 2-11-2014 at 16:59

Agreed. I wouldn't be putting copper (or probably any metal flakes) into soap. Mica sounds like a great idea. But if all you want is a sparlkey kind of look you could go for glitter instead. (Maybe.)

DrMario - 2-11-2014 at 17:02

Quote: Originally posted by UnintentionalChaos

I think you are looking for "cosmetic mica."

Something exactly like this: http://www.brambleberry.com/Gold-Sparkle-Mica-P3063.aspx
[Edited on 11-3-14 by UnintentionalChaos]

Wow. Rarely do I see a thread reply so perfectly solve the issue of the original poster. Hats off to you, good sir.

Metacelsus - 2-11-2014 at 19:31

What about iron pyrite?

[Edited on 3-11-2014 by Cheddite Cheese]

Little_Ghost_again - 3-11-2014 at 02:51

I will have a look at iron pyrite thanks, I want to stay away from mica's if I can help it.
Normally for a yellow on its own I use saffron or tumeric, but I want a different effect this time

vmelkon - 6-11-2014 at 14:56

Perhaps you can use aluminum powder.
If you use pyrite, you would have to break it down and it will produce non-shiny surfaces.

UnintentionalChaos - 6-11-2014 at 15:33

Quote: Originally posted by Little_Ghost_again

I will have a look at iron pyrite thanks, I want to stay away from mica's if I can help it.
Normally for a yellow on its own I use saffron or tumeric, but I want a different effect this time

Pyrites often come contaminated with arsenic from what I understand. They are highly dense and will settle out of something like soap. The powder is nonmetallic brown to black (fine enough, it is pyrophoric), and they smell of H2S.

[Edited on 11-6-14 by UnintentionalChaos]

Etaoin Shrdlu - 6-11-2014 at 15:48

Yellow iron oxide. There are some pretty bright grades, safe for cosmetics too. Bonus: cheap as dirt.

EDIT: Hmm, you want a flake specifically, though? Mica's really going to be your best bet for cosmetic grade material.

[Edited on 11-6-2014 by Etaoin Shrdlu]

Little_Ghost_again - 6-11-2014 at 17:17

Yeah not so easy for cosmetics, worse comes to worse it will have to be gold flake.
I might try some the other ideas just so I know the effects I can get from them, might come in handy one day.
I have founds all kinds of odd stuff that works with soap, sometimes you have to think a bit out the box.
Having said all that safety is always top consideration for any soap I sell. Colours and scents is the main areas I am working on. Slowly getting the hang of extractions, next is working on purifying and identifying what i have extracted. Although soon I will have some pretty neat help with that

j_sum1 - 6-11-2014 at 17:25

Can I ask, what is the problem with mica?

TheChemiKid - 6-11-2014 at 18:20

Yeah, it seems pretty ideal for what you are trying to do.

jamit - 7-11-2014 at 01:29

Quote: Originally posted by Cheddite Cheese

Alkyl xanthic disulfides and thioanhydrides have a beautiful golden-yellow color, and are also insoluble in water (but soluble in other solvents). If you can get carbon disulfide, they are easy to make.

They do not, however, have the thermochromic effects of lead iodide; they just melt.

What exactly are you going to use this stuff for? There are many possible yellow pigments.

[Edited on 2-11-2014 by Cheddite Cheese]

How exactly would you make Alkyl xanthic disulfides and thioanhydrides, that is, if you had carbon disulfide?

Metacelsus - 7-11-2014 at 06:00

React an alcohol with Na/K hydroxide and carbon disulfide to form an alkyl xanthate salt. Then, oxidize it (electrochemically or otherwise) to form an alkyl xanthic disulfide.

Thioanhydrides are more complicated, and require either desulfurization of the disulfide with cyanide or reaction of the alkyl xanthate salt with a chloroformate.

Note: While tertiary xanthic disulfides/thioanhydrides are possible to make, they decompose easily. Primary and secondary alkyl groups are best.

For more information, https://www.sciencemadness.org/whisper/viewthread.php?tid=28...

Still, now I know that the OP wants to make soap, these compounds are not ideal for that purpose: they melt in hot water.

DrMario - 7-11-2014 at 08:02

Quote: Originally posted by Little_Ghost_again

I will have a look at iron pyrite thanks, I want to stay away from mica's if I can help it.
Normally for a yellow on its own I use saffron or tumeric, but I want a different effect this time

Why do you want to stay away from mica? It's one of the safest cosmetic additives.

Little_Ghost_again - 8-11-2014 at 06:03

Quote: Originally posted by j_sum1

Can I ask, what is the problem with mica?

No problem as such with mica, except that its what everyone uses. Its too easy to replicate and its nice to be able to state no mica used.
I am a purest when it comes to soap, I get in a rage when people buy melt and pour soap base add a few drops of shop brought essential oil, add some colour with shop brought micas then stick it in a microwave oven until melted. They then sell this shit at craft fairs as hand made soap!!!
If I feel generous I would at the very best call it hand crafted, I get annoyed because my soap is hand made cold process, the scents and colours are extracted and collected by myself, in the last 4 years of entering competitions I have won a number of awards.
How I ended up here and interested in chemistry was because they changed the law, its a bit of a mess but soap is now kind of classed as a cosmetic, different EU countries though apply the law differently, if you make real soap then you now have to have it documented and certified as safe etc, this means each ingredient is analyzed blah blah blah.
Thats why I ended up wanting to get to grips with chemistry!
I have since discovered though that I like chemistry for chemistry sake as well

.
Hopefully next week I should have this bad boy to help out

The cost to get oils etc certified as solvent free and the cost per recipe is now around £185, so everytime I change a recipe I have to pay out to get it cleared. However the law actually says that this needs to be done by a competent person, its just assumed this is a chemist, reality is though that my dad being a biologist would qualify as competent. So it was decided that as I have over 500 recipes now and will be selling larger amounts of soaps we would get the above equipment.
Which leads me to one other thing.
We will offer a cheap service to SM members, the GC has 3 columns covering polar non polar and mid ranges, it also has the nist database etc so anyone wanting GC analysis doing cheap give us a shout

Little_Ghost_again - 8-11-2014 at 08:47

Quote: Originally posted by Cheddite Cheese

React an alcohol with Na/K hydroxide and carbon disulfide to form an alkyl xanthate salt. Then, oxidize it (electrochemically or otherwise) to form an alkyl xanthic disulfide.

Thioanhydrides are more complicated, and require either desulfurization of the disulfide with cyanide or reaction of the alkyl xanthate salt with a chloroformate.

Note: While tertiary xanthic disulfides/thioanhydrides are possible to make, they decompose easily. Primary and secondary alkyl groups are best.

For more information, https://www.sciencemadness.org/whisper/viewthread.php?tid=28...

Still, now I know that the OP wants to make soap, these compounds are not ideal for that purpose: they melt in hot water.

Melting in hot water might be a plus! I will need to try it.
The point about all this isnt just get some oils and make a bar of soap, I sell soap and for many reasons decided I wanted to sell alot of soap. So I enter high end competitions etc and have a really good reputation for unusual soap,I have only been doing it on this scale for around 3-4 years, but have made soap with my gran since I was 5 years old.
My Gran was a life long soap maker and left me her notes and recipe book when she died. Without wanting to say too much, there is a member who has helped me get the business side up and running, I have developed a special soap that a very large UK super market want to use in there stores (not for retail).
On the face of it the soap they want would seem bonkers, but it has some pretty special properties.
Anyway it reached the stage where knowing about soap isnt enough anymore, I need to back it all up with chemistry. Also the major changes to the law mean I can get a jump on the competition, this year there was hardly ANY cold process soap for sale, most people have switched over to melt and pour (known as shit soap).
Soo hence why I am here asking what must seem nooby stupid questions,
I read the books and links you post, then I realize that often I have asked the wrong question!! But I am getting there.
My family and others back me 100% in what I am doing, I have sunk every penny I saved since birth into doing this properly, and others have helped a great deal.
So in a nut shell that is why I need to ask about things that are a bit different.

Metacelsus - 8-11-2014 at 11:17

If you really want to put those compounds in soap, be warned that their toxicity has not been studied (it's expected to be low), but that the xanthate salts used to make them are harmful to certain aquatic life. Also, I'm not sure if they would dissolve in soap or not.

Mica is probably best.

DrMario - 8-11-2014 at 12:07

Quote: Originally posted by Little_Ghost_again

Quote: Originally posted by j_sum1

Can I ask, what is the problem with mica?

No problem as such with mica, except that its what everyone uses. Its too easy to replicate and its nice to be able to state no mica used.

Yeah, I'm still not getting the point. Mica is safer than the alternatives listed so far.

As for you being a purist, maybe keep in mind that many essential oils contain carcinogenic substances. Just a little FYI.

Little_Ghost_again - 8-11-2014 at 13:26

Quote: Originally posted by DrMario

Quote: Originally posted by Little_Ghost_again

Quote: Originally posted by j_sum1

Can I ask, what is the problem with mica?

No problem as such with mica, except that its what everyone uses. Its too easy to replicate and its nice to be able to state no mica used.

Yes all points worth mentioning. Reading the books mentioned above it says about solvent extraction followed by steam extraction for some.
I have nothing against mica and I use it for some soaps, but there are times when I look for something completely different. There is a member here who is aware of one ingredient that is used for a specialty soap I make, it is unique and could possibly lead to great things for my little soap company (ok its in mums name cos I am too young).
Its a shame I cant just blurt out why I dont want mica for this, but for what i am trying to do mica isnt the answer this time.

Just some general info

Our house is very very old, but there has been a dwelling on this site since stone age man. If you google our address or the house you will find a document that relates to when the A75 road was widened a few years ago, they had to do a archeological survey, they found we have a upper paleolithic water course here.
We didn know where it was until about 4 months ago! As we have only lived here 18 months (ish), it turns out its behind one the stone walls and then comes out to what we thought was just a drainage channel! except the channel is lined with tiny stones, it looks like a huge amount of work for a small stream, but apparently its part of this water course.
We also have 4 wells,one is also mentioned in the report as being from the bronze age, at the back of the house we have a bronze age burial mound.
ANYWAY...................
We have thousands and thousands of many different daffodils and narcissus, in victorian times there was a guy living here that collected them, over the years they have cross bred etc etc, we now many so many different types its really jaw dropping in the spring when they start coming out.
we have one type in particular that has a pom pom flower thats a double head, the smell from it is unlike any flower smell I have ever smelt before.
Its deff a hybrid from a hybrid from a hybrid!you can kind of look around the patch and see what must have crossed with what. Most daffs dont really smell, this one does and the smell is hard to describe, but everyone that has smelt it (its really powerful and a single flower fills a room with scent for days) really loves the smell.
Its one of the scents I want to isolate and use.
As for cancer agents etc thats kind of one reason I am here, I am willing to work hard and learn, I am slowly building up the equipment to be able to test oils etc to make sure they are safe to use.
But like in this case sometimes I cant use the obvious choice for things. I am not a huge fan of mica anyway but I do use it when needed. I generally prefer natural plant dyes and colours, but obviously that can be a real nightmare when used with cold soap process. Some act like litmus indicator, so your soap starts out red and 5 weeks later its blue lol.
My Gran made soap for over 65 years and she was great at it, but these days you cant just make great soap, there are now so many rules and regs its getting silly.
I might do a post one day on soap making, most people use online calculators for working out the sap values etc, but these are average figures they give, obviously thats why most use a lye discount of around 5% to make sure all the hydroxide gets used up, I prefer to use a discount only when intentionally super fating a soap.
Its only since I have had to delve into the chemistry side of soap that its given me a chemistry interest, before that my main science interest was Biology.