[quentin]

Hi,

I am currently working on the chemical etching of zirconium oxide (ZrO2), but chemistry is not my specialty so a little bit of help would be really welcome =)

The experiment is quite simple : I put a ZrO2 sample in a hydrofluoric acid solution (48% wt) for different times at room temperature.

My aim right now: knowing (theoretically) what are the reactions that can take place, what are the products that actually appear and what mass of ZrO2(s) can be dissolved in the solution

My questions : what is the methodology that I should follow to get this information ? And maybe which kind of diagram should I calculate ? (by the way is there some freeware that can help me for this kind of work ?)

Thank you for your help !

[Arkcon]

Hi,

I am currently working on the chemical etching of zirconium oxide (ZrO2), but chemistry is not my specialty so a little bit of help would be really welcome =)

The experiment is quite simple : I put a ZrO2 sample in a hydrofluoric acid solution (48% wt) for different times at room temperature.

OK, we'll try to work with you on these, but this may be difficult, if you really don't know basic chemistry.

My aim right now: knowing (theoretically) what are the reactions that can take place,

OK, the reactions do have names, we'll try to show you what they are.  Why do you need the name?

what are the products that actually appear

That will depend on what is actually happening.  We call these reactions double replace,ment or red-ox reactions.  Its hard to know what's happening just by theory.  Often, people conduced the reaction and looked afterward to understand the products and what's happening.

and what mass of ZrO2(s) can be dissolved in the solution

OK, once we know the reaction, this is pretty easy to find out.  But the devil is in the details.

My questions : what is the methodology that I should follow to get this information ? And maybe which kind of diagram should I calculate ? (by the way is there some freeware that can help me for this kind of work ?)

NO.  I don't think this is something you can just diagram or compute, so its not likely anyone wrote a program around it.
Thank you for your help !
[/quote]

[quentin]

Thank you for your answer ! Maybe I should give you a little bit more details on what my specialty is and why I am working on this: I am a PhD student and my specialty is Materials Science. So yes I know some basic chemistry but my knowledge is limited to what I learnt in my classes and I never had to start from scratch to analyze a problem like this one.

The main focus of my work is not the chemistry, but the study of the surface of the zirconium oxide after the chemical etching. However I would like to understand what is happening ! at least what can theoretically happen (because of safety problems it's not easy to do elaborated experiments with HF...). I did some bilbiographic research, resulting in very few results. I put a paper in attachment in which they calculate Pourbaix and solubility diagrams but why they do it and how they do it remain quite unclear for me.

So like I said any help will be welcome ! =)

[Arkcon]

I don't understand what a Pourbaix diagram is supposed to represent, and although I know what a solubility diagram is, its a lot for me to process, quickly glancing at the paper.  Maybe, like you said, you'll begin to understand better, once you've read the references.  Or maybe, the references found in the references, for the most basic concepts.  Or, if you can find the author in Science or Nature, they'll give a simpler summary.

[quentin]

Pourbaix diagrams are also known as pE/pH diagrams, but I'm not sure the method they use in this paper is the better way of doing. But this is the only one I found that deals with the chemical etching of zirconia with HF.
If you have your own opinion on the way I could solve the problem it would be really helpful !

[Arkcon]

Well, leats try to begin to figure it out ourselves.  We start with ZrO₂, a solid, and we add HF, a solution in water.  We "etch" the ZrO₂, so its no longer a solid.  What is happening?  What happens to the HF?  I suppose you can conclude, you can only etch as much ZnO₂ as you have HF, but how will you compare the amounts?

[quentin]

Experimentally, I can know how much zirconium oxide has been removed by weighing the sample before and after the attack
Question is what happens to ZrO2, i.e. how does it react with HF (or F-)  ? this is what I don't know... and I dont know how to determine it