Chemical Forums
Specialty Chemistry Forums => Citizen Chemist => Topic started by: Krnkarina on January 25, 2016, 11:33:13 PM
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Hello, my name is Karina and I live in Jakarta, Indonesia. Im a college student, currently studying chemistry.
Im hoping someone can help me out, cause im going desperate.
So I've always love flowers. so i was browsing around youtube and i stumble upon this video about a technology to preserve flowers using chemicals like ethanol and gylcol.
here are the links, please check them out.
https://www.youtube.com/watch?v=N3u-4B7d0qo
https://www.youtube.com/watch?v=YKP4LR8rBaQ
https://www.youtube.com/watch?v=Y0N7C0LXNEo
so i search the internet for journals and articles about this method, and they confirm this methods. maybe differ in what kind of glycol they use.
so the point of this method, is to substitute the flower moisture with a substance that's less volatile.
the steps are:
1. dehydration, both the video and journals that i found uses ethanol. so i used ethanol too. the video shows a change in physical appearance like color bleaching, and bubble. they did this by soaking in ethanol (primary solvent)
so now, the flower is filled with ethanol.
2. substituting the ethanol with a less volatile substance (secondary solvent). the video said they used glycerin or glycol. in the journal i read, polypropylene glycol (PPG) gave out the best result. they did this my soaking in the substance
3. drying. both the video and journal did this by just air-drying it.
i think i did step 1 right (dehydration) because i got the same results as the video.
now the problem is the substitute, i tried several substance, i tried glycerin, propylene glycol (PG, not polypropylene glycol), i tried a solution of half ethanol and half gylcerin (because glycerin alone has a very high viscousity), and i also tried a solution of 30% ethanol and 70% propylene glycol.
i failed because after they dried, they all shrink and dont have the fresh flower structure as i hope it would. and the drying process was very loong.
in the video, they mentioned something about ethanol as a catalyst? id like to know what everyone thinks, and what kind of other substance or mixture i should try. and id like to ask, theoretically, can glycerine or glycol, substitute the ethanol in the flower? the journal said it can, cause glycerine and glycol has a higher affinity.
please if anyone has an idea, or maybe advice. please help me out. i attached a screenshot of the video.
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You might try lowering the viscosity of glycerol by mixing with propylene glycol instead since it won't readily evaporate.
I would think glycerin or propylene glycol would not significantly dry in normal conditions. How long were you drying them for? If it dried in less than a month then this may be because of substantial residual ethanol and you may need to increase the second stage soak time.
Any wetness from residual nonvolatile solvent would probably be best removed by just swishing the flower around briefly in ethanol to get rid of their excess on the surface, and then letting the ethanol dry.
I don't think the use of ethanol is a matter of catalysis. I don't really know of any kind of reaction that is being attempted here, as far as I would think this is just a matter of replacing the water in the flower with a less volatile solvent. The ethanol is just there to serve as a good intermediate solvent. I believe you need multiple stages because with just one you can end up dehydrating the flower with a viscous hydrophilic solvent since that will pull out the water faster than the solvent can penetrate to replace it.
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Hi guys,
I've also been attempting to embark on this experiment. I've gotten as far as drying the flower and allowing it to maintain its shape and texture, however, I also have had a few setbacks.
First, I'm wondering if my inability to obtain polypropylene glycol and thus being forced to use propylene glycol is killing my attempt from the start. Also, I'm using denatured ethyl alcohol instead of non-denatured.
The color is not nearly as bright as the videos and when I do the ethanol rinse after the PG, some of the colors seems to leave the petals. I feel like the color saturation issue may be as simple as a longer exposure to a stronger dyed PG solvent, but all of my attempts have come out similar regardless of soaking time.
Any help would be greatly appreciated, as I'm trying to make my soon-to-be fiancé a massive bouquet of roses that will hopefully last until our wedding.
Thanks, in advance!
Bobby
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Denatured alcohol should be in the vicinity of 90% ethanol and won't deviate too much from how neat ethanol would dissolve things.
Could you fully detail what process you are attempting step by step and the observations you have made along at each step? In particular are you adding some kind of additional dye?
If the color is all leaving with the brief ethanol rinse at the end then it would seem that the propylene glycol is a good solvent for whatever makes roses red. Thus when you wash some of the excess PG out you wash out some of the color.
It could also be the ethanol but that seems unlikely given the very brief exposure. However it would be easy to test by seeing if the color seems to leave if you rinse with dissimilar solvents which are still compatible with PG. Acetone and water come to mind.
If it is the propylene glycol dissolving the color then you might try replacing it. The only other readily available chemical I know of for this is glycerol, but this would have to be mixed with something to lower its viscosity. There is a small chance that some mixture of PG and glycerol would avoid dissolving the color from the rose.
You might also just try to saturate your PG with rose color before using it. It might be as easy as adding a lot of crushed dried petals to the PG and heating/stirring. If the color is leaving at the dehydration step then you might try something similar with whatever solvent you are using there.
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I happened on a page of scientists offering extraction methods for rose pigment.
https://www.researchgate.net/post/How_can_I_extract_natural_dye_from_red_rose_petals (https://www.researchgate.net/post/How_can_I_extract_natural_dye_from_red_rose_petals)
From this I learned that the color will change from a gorgeous red to eww with increasing alkalinity.
It is possible then that the color might be enhanced with an acid.
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Thanks for the reply! Rereading my post, I noticed I was definitely unclear at some of the steps.
The process that I'm using is the same as Karina with the inclusion of the ethanol rinse.
The process that has yielded the best results has been this:
1. Dehydrate by placing the rose in a denatured ethyl alcohol bath overnight.
2. Transfer the rose to the PG bath (mixed with red floral dye) and allowing to soak for 2-7 days.
3. Rinsing the rose with the DEA briefly.
4. Allowing to air dry.
After the dehydration step, all of the color is removed from the rose. The flower also becomes brittle to the touch.
After the PG step, the rose regains most of it's flexibility and overall texture. It also regains some of the color due to the dye.
After rinsing, the rose is able to dry without wilting, however some of the previously regained color is lost (though this may just be some of the colored PG that is stuck between the leaves).
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I would try saturating both the ethanol and PG solutions with rose pigment from petals before using them to process a flower. The existing pigment in the flower should be mostly left alone if the solvent cannot dissolve anymore. This may not be practical if the solubility is too high. I would test this by seeing how many petals needed to be added to a small sample of ethanol so that some color remained in the petals. Soaking in the fridge or possibly the freezer might work best since the solubility will be at a minimum at low temperature.
Using another red pigment instead will yield whatever amount of red color is dissolved in the PG that remains in the flower indefinitely. This will be a very thin bit of PG, only as thick as the petal. As a result the color would have to be fairly intense to be noticeable. Unfortunately this color will also be present in the PG in the stem and leaves which may compromise their normal green color. With enough dye, you should be able to at least get a pink rose before any change in the green parts becomes noticeable. However, I doubt you could get a deep red rose without side effects.
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Hi everybody,
I’ve tried to preserved flower according to the composition of Glycerine and Propylene Glycol in the preservative solution. And I succeed. This is receipt which I use: 74.9% alcohol, 10% glycerine, 15% propylene glycol and 0.1 % Tween 20. But I have a problem with colures, I don’t know which colures I have used for dye. Can you help me with advice for dye and which colures are the best for dye flower?
Thanks Alexandar
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Hi Aleks
Did you succeed to make a product? Can you show for everybody here a picture?
I tried many time before, 15%G, 15%PG, 70% Methanol, and many percentage (around 100 times)
I have no problem with color, but percentage with PG, glycerol and Methanol very hard (I used Methanol, do you think Ethanol for best result?)
And how many hours in that mix? I really care about this topic.
Tks
Dzung.
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Hi guys.
After many time test, I bought a product from Japan (mysty - from the-flower.biz). Thier poduct had nice result, not really perfect but look very nice. And I knew, only glycol or glycerin and ethanol is not enough, please check them out. That kind of chemical is very importan.
Tks.
Dzung.
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thank you for all of the reply. I so glad to know that there are many trying this experiment.
up until now i still havent succeed on retaining its shape, it still took a long time to dry and after it dried there are many wrinkles. but at least the flower stayed that way for a veey long time (i threw it away after six months)
dear NDsoll137, what is denatured and non denatured ethanol? maybe i can use that.
dear Aleks, I think we've been reading the same journal. but i still havent succeed. i was wondering what grade of reagant are u using? I ve using just a techical grade, maybe that my problem too. maybe i should be using a pro analys reagant?
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Dear All,
I just check your conversation and I am very interested on it. On the third video and on a patent I've found, we can improve the dying method by using a molecular sieve. I think it can absorb the water of the flower during this process.
Regards,
Mikael
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Hi all
If you know about chemicals and you like rose. Let's contact me via *email deleted*
This is my products
Thanks
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Hello nice to meet you
my name is Jesus 'm from Costa Rica ,
I want to know about the method to preserve roses.
I have made several failed attempts.
1 dehydration with ethanol 96%
2- propylene glycol and glycerin and coloring food use.
3- drying outdoors.
but the result is not good ...
could you tell me that I am failing please .
excuse my English , I'm using google translator .
thanks blessings.
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What kind of dyes did you guys use? Store bought food coloring, or something else?
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The mysty product website works fine for me, albeit a bit slow to load.
http://the-flower.biz/?p=37 (http://the-flower.biz/?p=37)
They use the same sort of process as discussed throughout this thread.
You soak in one solution to dehydrate and remove color and then you soak in another solution to dye and to replace the solvent with another that won't evaporate.
I decided to do a little testing of my own.
I was interested whether it would be possible to find a solvent which preserved the color while displacing the water.
So, I bought a red rose to test the effect of various solvents on petal clippings.
Methanol was very effective at removing color.
My subjective impression of their relative strengths:
Dimethylsulfoxide>=Methanol>Acetone>Ethanol(~95%)>Isopropyl(91%)
The DMSO acted much slower than the methanol, but over a couple days, it has rendered portions of some of the petal clippings transparent.
The alcohols only achieved translucency.
A drop of HCl into the acids immediately turns the solution a bright red, demonstrating the pH-dependence of the rose anthocyanidin pigment.
Even the isopropyl removed a great deal of color and I doubt that it would be easy to preserve a red rose with the original color intact by this sort of procedure.
However, if you want to dye your flowers anyway then methanol seems like a good initial solvent.
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Hi there,
I am also trying to preserve roses. What I did so far:
1) Let petals soak in 96%-ethanol for a day. The red petals lose most of their color and look light pink after a day.
2) Mixing ethanol with polyethylene glycol and adding dye (procion mx).
3) Putting petals into the mixture and let it soak for 1-2 days.
4) After removing the petals from the mixture, I rinse them with ethanol for aminute, so that the excessive polyethylene glycol gets removed from the surface. Otherwise it looks like plastic.
Now my problem is the following: Before the petals get dried, they look pretty transparent. But every time the petals get dried by air, most of the area of the petals gets "white" within a couple of minutes in a weird way. It seems when the alcohol is evaporating, it destroyes the cells? Or is it supposed to show this weird behaviour? This process doesn't occur all over the petals. Which looks pretty bad in the end. Any idea what is happening there? Any idea how to fix this?
I can't insert pics here, so please follow the link to the pics of the petals:
https://ibb.co/kigbHb
https://ibb.co/dcWMiG
https://ibb.co/hBksqw
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Hi, I also tried to stabilize the roses but I'm not satisfied with the results at 100%, in the first bath I use alcohol denatured 90 ° leaving the rose for 24/48 hours (I look at the petals that are transparent) and this pasage gives me much well, the second bathroom (which does not satisfy me 100%) and glycol propylene ninety percent and ten percent glycerine, and then a little food coloring I leave the rose for 2 even 7 days then I leave them to dry in the open air but they dry very slowly after 1 month the petals are still a little damp from the second bath, the flower is beautiful but stains everything that is close to them and then and a little wet not like those endings on the internet. I would like to know the real recipe too.
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Alright folks, I've only done this once before, but I think this another Citizen Chemist thread that's run its course, so I've locked this thread.
Preserving living tissue touches on important chemistry concepts -- dehydration and replacing moisture with preservative is what is done with histology samples. And its great to use science to advance our crafting skill and highlight our artistic ability.
However, the endless pseudo advertisements, and post after post about how we all have to email you the steps that are already in this thread so you can quit your day job and make a living with this are going to have to stop now.