There are versions of SEM apparatus that can operate at low-vacuum (LV) or even "environmental" conditions (4k Pa), if vacuum-compatibility is the only issue. Other possibilities would be using cold-stage, which can maintain you sample in frozen, solid form. Of course this are just methods, everything depends on what you want to achieve by SEM analysis itself...

What do you want to investigate? I guess you want to perform an elemental Analysis, right?

What is your "oil"?

Julian Opel is correct, answering your question would be easier if the nature of your "oil" is known. Knowing if you're aiming for qualitative or quantitative analysis would be nice as well.

For instance, if you want to determine residual metals, I advise you turn to XRF or digestion/ICP.

There are versions of SEM apparatus that can operate at low-vacuum (LV) or even "environmental" conditions (4k Pa), if vacuum-compatibility is the only issue. Other possibilities would be using cold-stage, which can maintain you sample in frozen, solid form. Of course this are just methods, everything depends on what you want to achieve by SEM analysis itself...

Thank you everyone for your thoughts.

Julian Opel and Pierre Caulet , I meant to say that my compound has oil-like consistency and I'd like to observe the structure of the compound using SEM.

Janez Zavašnik Thank you once again, however, the SEM we use requires 'powder' as samples. Therefore, I'm looking for ways to dry compounds which have oil like consistency.

Thanks for providing details Genyir Ado

I understand you want to solidify your sample and grind it then, not dry it (does it contain water ?) ?

Rather, I'd suggest you look into the WetSem capsules from Quantomix (https://www.emsdiasum.com/microscopy/products/sem_wet/technical.aspx)

Don't know whether they still exist but if not you might find capsules on Amazon.

Those were developed some years ago to allow wet samples to be observed within a traditional SEM with no Low-vac capacity. I've used them in the past to look at dispersed minerals and I suspect they might allow you to directly look at your sample in its flowing state.

An alternative would be to freeze them as Janez Zavašnik suggested, using a cold stage. If you don't have access to one, try and plunge your sample in liquid nitrogen and quickly observe it (will depend on your sample, its melting point, its sublimation behaviour and whether its structure is preserved when solidifying).

I would not recommend to Environmental SEM owners to put potentially contaminating oils in their microscopes (it's partial oil pressure that matter, not overall pressure). Of course, there are dedicated "dirty" ESEMs, the problem is in finding them.

If you are interested in sediments/impurities, you can separate them. If you are interested in oil itself, the SEM is one of the worst methods for the task unless you have a cryo stage.

Genyir Ado than this is a Problem if you have an oil and you want to see the structure of the oil but you can only use powders. Than even drying of freezing would result into another structure.

As mentionend, enviromental SEM might be possible. how big are the motifes you want to observe? sometimes light microscopy will also works and with the right settings you can find out a lot.

Dear Genyir Ado , I just found your explanation to your question. I want to point out that there are no SEMs that require powdered specimens.

Genyir Ado is your problem solved? if yes could you please let me know how cause I have the same problem.

thanks