[dFrem]

Dear Everyone,
please help me with an advice. The task is to create the (gel-like) substance which will melt when it will be heated simultaneously to emit the oil within certain flavor to indicate the danger.
The temperature of the heating should be about 70C.

please suggest some not complex solution or a direction to look for.
Thanks!

[Furanone]

A high molecular weight ethyl cellulose (about 2% w/w but higher will make firmer gel with less oil syneresis) will turn to a gel with vegetable oil after heating to about 120 C. I am not sure if remelting gel can be obtained at a lower temperature you desire of 70 C, but it possibly may be obtained by instead of adding all ethyl cellulose, you add a mixture of ethyl and methyl cellulose (very small amount). You would have to run some experiments to find the sweet spot. Too much methyl cellulose and it may not dissolve in oil and you will see clumps.

Ethyl cellulose is currently not food-grade but is going through the process, but methyl cellulose can be obtained as food-grade (I am assuming you mean a vegetable oil and not petroleum oil since you mention flavor). I do not see why ethyl cellulose would not be approved since there are many chemically modified celluloses (carboxymeythyl cellulose, hydroxypropyl cellulose, methyl cellulose) that are all approved for use in foods as texture modifiers at their typically very low levels, as they are found to be a fiber and pass through the digestive tract without any human health issues.

[dFrem]

Hi Furanone, thanks for your answer! But if I'd like to use this substance in a device and will melt it down in some, as example, critical situation as an alert sign etc.?
the point is to prepare the gel, containing the flavored oil or whatever with the strong smell to indicate the cause.
I broke my mind while thought for a resolution…

[Furanone]

I am not sure I understand fully then. Are you talking about like an encapsulated fish oil type pill that has a very hard gelatin capsule surrounding the fish oil? This might work then, and gelatin has a much lower melting point too, but is very hydrophilic so completely immiscible with your flavor oil.

The 2% ethyl cellulose gels will completely dissolve in the 98% oil and then form a polymer network trapping the oil in. A gel can form with substantially less than 2% ethyl cellulose but will not be as strong (solid), and will have more oil syneresis.

[Arkcon]

I don't know why, dFrem:, you're locked into this particular format, and if Furanone: wants to play along, that's fine, but if we lock formats, it may not be possible.  Some insights:

We often get similar problems -- someone needs a temperature indicating material and wants to make it from scratch.  I always tell people that the Omega Corporation has made temperature indicating chalks, crayons, indicating labels, etc since I was a child, so why do they have to design their own?

http://www.chemicalforums.com/index.php?topic=74227.msg269235#msg269235
http://www.chemicalforums.com/index.php?topic=52631.msg194535#msg194535
http://www.chemicalforums.com/index.php?topic=63806.msg230650#msg230650

I'm wondering if we're facing some sort of language barrier.  Why does it have to be a gel?  Why not a wax, or a low melting plastic?  Why does it have to release an oil that you've scented with a warning scent?  WHy not have the wax or plastic release a scent molecule on its own?

[dFrem]

Hi! Thanks for a new data for me. Then let me explain what's the matter. The aim is to provide an opportunity to use simple as possible formula to create the substance as on the picture below, should be placed onto the heater and after it will be heated emit a scented component into the airflow.



many thanks for your links on Omega Corp.'s products, never heard about them. I'm not good in chemistry, therefore I'd be grateful if you would suggest some certain direction or a person who could help. Ready to pay for a help.

Cheers!

[dFrem]

Hi Arkcon, I studied Omega's catalog. There is no that I'm looking for, may be my previous post will cast light on it…
Please suggest something, can't find anything in Internet

[Arkcon]

Have you tried anything?  If you embed a bubble of scent in a low melting point wax, can you smell the warning scent when you send warm air over it?  This will depend on the volume of the air handler and the rate of air flow.

[billnotgatez]

This is a divergent thought and may not apply (since it is a solid and not the gel)
but I seem to remember
Eutectic substance that would be solid but would melt at a defined temperature based on mixture of the constituents
https://en.wikipedia.org/wiki/Eutectic_system
for instance one entry in the above link

"Solar salt", 60% NaNO3 and 40% KNO3, forms a eutectic molten salt mixture which is used for thermal energy storage in concentrated solar power plants.[8] To reduce the eutectic melting point in the solar molten salts calcium nitrate is used in the following proportion: 42% Ca(NO3)2, 43% KNO3, and 15% NaNO3.

Maybe you could mix it with the gel

Sorry if this is a digression

[dFrem]

@Arkcon not yet, just was stunned because didn't know what to start for. more detailed characteristics of the environment, and the last ones I got, is:
- the air flow is comparable with computer's fan (39.88 CFM)
- the heater's power 720 J/s
In this case I'm still thinking on the technical implementation because of the lack of energy.

@billnotgatez thanks for an information, will read it carefully. But I think it's a lil bit not that direction.