Hi! This is my first post here
I would like some advice on how to dry a powdered slurry back into fluffy, free flowing powder form with minimal to zero moisture content.
I'm working with borosilicate glass microspheres. A very very very fine powder.
The powder gets washed in distilled water to separate out the microspheres that float and the ones that sink. We want the floating ones.
The slurry with floaters then is filtered and dried on filter paper / Buchner funnel by vacuum.
The end result is a very dense puck that's fairly brittle after drying overnight.
Instead, I'd like to have a non-clumped, free flowing, very very very very fine powder that acts the same as the starting material.
I've started adding a final wash step with some ethanol to increase the drying efficiency and help remove the water, but it's still not the same fine powder consistency as before.
I'm wondering if there's a salt or solvent that helps to kind of push apart the surface interactions of the borosilicate glass microspheres, as I think that's why they are sticking to each other (or perhaps I'm completely wrong). I think there's definitely some sort of interaction going on between the microspheres and whatever solvent it's in. For example, microspheres in distilled or deionized water acts different than microspheres in unfiltered tap water. The microspheres form a plug in the tap water, but in dH2O or dI, the plug is much more easily agitated and returns back into slurry form easily after shaking.
Any ideas or comments would be greatly appreciated! Thanks!