Actually I'm working on Chitosan-Eudragit nanoparticles and I've got good size and zeta results but now that I'm trying to dry my emulsion and turn it to solid powder, the result is a sticky oily powder which can not be coated with Au for SEM imaging. I've tried usual oven, vacuum oven, using organic(acetone) environment and added my emulsion dropwised to it an let it evaporated and again what I got is that sticky oily thing. at first I taught maybe it's because of my excess surfactant(tween and benzalkonium chloride) and I decreased the amount of surfactant, even I decreased and optimized the amount of my polymers again but all I've got is that sticky oily thing. Any idea...??
Iman Godazi
Do not try to dry your system. You will no longer have nanoparticles if you do. You cannot dry an emulsion.
See:
- Dispersion and nanotechnology
https://www.brainshark.com/malvern/vu?pi=zHSznNgprz5chz0
- Adhesion and cohesion http://tinyurl.com/zwb2wlh
Alan F Rawle thanks Alan it was very helpful but I still need some pictures of my particles in order to put it in the article as others do. I do not have access to any TEM microscope and this was why I'm looking for an answer.
Thanks again
Iman Godazi
Just put a drop of your original material on the SEM stub and allow to 'dry'. No need to coat.
Everything on the TEM is an artifact of sample preparation and particle selection.
Alan F Rawle Really...?? the operator of SEM told me you have to dry it on a piece of Aluminium foil in order to be coated...!! and when I do the drying procedure it turns to sticky oil and he says it can not be coated...!!
Iman Godazi
You won't know if you don't try it. If you have particles > 1 um or so then you may get some information from visible light microscopy (and many 'nano' systems are actually microns in size, I've found with experience...).
The classic route foe emulsions is freeze-fracture. You may want to look at cryo-EM and the ASTM standard in that area.
Alan F Rawle
Actually my particle size is about 120-130nm in Malvern Zetasizer and I was looking for confirming that with the SEM imaging.
I'll do what you said and I'll let you know what happens. Thanks for your time Alan I really appreciate that.
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