DOE- organic synthesis

Question

Hi all,

I am trying to set up a synthesis optimization using JMP's DOE.

I have two continuous factors Time (12-24h) and temperature (160-200oC).

I then want to include a mixture of three chemicals: Citric acid, urea and formamide.

I read up on using the mixture factor feature on JMP's guide but my mixture don't like the idea of all adding up to a sum. This is problem number one currently.

I expect I will also need a hand trying to make these factors 'confounding'.

Would be very eager to learn from people and would appreciate any help I can get.

Acknowledgement will be given in any forthcoming publications if this works out.

Thank you in advance.

SignalRaccoon37 · Answer

Hi, thank you so much for your response.

Please forgive this long response.

I have spent the last few months reading up on the hydrothermal reaction utilized for my carbon quantum dots.

Essentially I know what I am expecting, especially at higher temperatures.

In brief, a hydrothermal reactor contains a Teflon tube, inside that tube the two precursors (citric acid and urea) and the solvent (formamide) are placed. The chamber is then sealed and placed inside an autoclave.

The autoclave temperature and rate of heating (rate of temperature change up to the max) can be set. The time of reaction (time at max temperature) can also be set using the autoclave. These, from my basic understanding of DOE are my continuous factors with a set value range.

The responses I want to monitor as you mentioned are:

* efficiency of synthesis for blue, green, yellow and red carbon dots
* Quantum yield of blue, green, yellow and red carbon dots.

To your point about the mixture: I am not sure how I can learn more about this as I don't seem to understand it perfectly. When inputting the following (mixture png) I have changed the mixture sum to 33 (grams in my case). So I have an upper limit that I want of citric acid (3), (urea 2) and formamide (28) but it wont let me input the 2 for urea as it equals exactly 33, which is the part that is confusing me.

I wont type further at this point as I don't want to add too much text. I have no support at my current institution with this but I really would like to employ DOE for my experiments and show other colleagues later on so I really appreciate any help I can get :)

mixture.png

statman · Answer

How are you setting your factor levels and linear constraints?  On the first screen, you can set the Values for levels.  Remember these are proportions (vs. actual levels). When you select continue, you can set Linear Constraints.  This is where you put 1 in the ≤ box.  Then select the design you are interested in from the list.

https://www.jmp.com/support/help/en/17.2/?os=mac&source=application#page/jmp/factors-7.shtml%23ww270179

You might want to watch this:

https://community.jmp.com/t5/Mastering-JMP/Designing-Mixture-Experiments-Part-1/ta-p/546086

Seems Custom design would be a good option as you can also add the 2 process factors to the Mixture design.

SignalRaccoon37 · Answer

Hi! Very sorry just noticed the typo!

Thank you so much for your response.

So, if I set my mixture sum to 1 I would want my three mixture values in that column to add up to 1 (or this is how I at least think this should work). If I set citric acid as 0.2, and urea as 0.2, it wont let me set formamide as 0.6, it keeps it at 1. However,  what I found interesting was the fact that I could instead type in the value of 0.7, which would result in a higher sum of 1.1.

I will try make my next responses more specific with screenshots.

Thank you again!