As you know, we can get this value from XPS AND it will be the practical value. However, the calculation of the theoretical one can be done by which equations!!
Dear Alaa
The theoretical C/O ratio is definitely calculated from the chemical formula of compound(S)
For example, if you go through the attached article " PLA-PMMA blends: A study by XPS and ToF-SIMS" you can see in Table 1 the relative atomic concentrations (%), experimental and theoretical C/O ratio, for 100% PLA, 80% PLA, 50% PLA, 20% PLA and 0% PLA samples and next to this figure the chemical formula of PLA and PMMA.
Now for PMMA:
Theoretical C/O ratio= number of carbon atoms/ number of oxygen atoms
= 5/2=2.5
And for PLA:
Theoretical C/O ratio= number of carbon atoms/ number of oxygen atoms
= 6/4=1.5
Then at any mixing percent the theoretical C/O ratio is calculated by the following simple equation:
Theoretical C/O ratio for mixture = Theoretical C/O ratio of PMMA * % PMMA+ Theoretical C/O ratio of PLA * % PLA
Thank
Thank you Dr Mohammed Hussein,
I checked it. You are right. However, there are theoretical values for 20% and 50% PLA. How did they be calculated??
Regards
Dear Alaa
At any mixing percent, the theoretical C/O ratio is calculated by the following simple equation as mentioned in my previous answer:
Theoretical C/O ratio for mixture = Theoretical C/O ratio of PMMA * % PMMA+ Theoretical C/O ratio of PLA * % PLA
For 20% PLA, C/O ratio= 2.5*80%+1.5*20%=2.3
For 50% PLA, C/O ratio= 2.5*50%+1.5*50%=2
Regards
Thank you. Now it is clear. If I want to apply that for graphite and graphene oxide. What do you think?
Define the linear chemical formula of your graphene oxide as: CxOyHz depending on the methods of the chemical oxidation of graphite you follow, then use the values of x and y to calculate the theoretical C/O ratio from the following simple equation:
Theoretical C/O ratio= number of carbon atoms(x)/ number of oxygen atoms(y)
Thank
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