Hi Razieh,

Which AFM do you use? It is a pretty common problem in Veeco/Bruker AFM liquid cells. Try to remove all bubbles from the syringe and the filing tube before filling the cell and don't suck liquid back with the syringe (just keep the second hole open during filling and close it only when there is some liquid in the tube).

Good luck!

Dear Razieh Bakhshandeh ,

in addition to the answer of Denis Korneev ,

you should outgas*) any water you use; for example by cooking for a while, prior to its use...

It may help a bit, but does not suppress capillary force/surface tension effects .

I admit, that I am not familar with your application; but is it possible to apply a bit 'soap' to reduce the surface tension?

*) dissolved O2 and CO2

Good luck

and best regards

G.M.

Some ultrasonic cleaning devices support special degassing modes for liquid solutions (by pulse frequency variation) . Maybe degassing water by ultrasonic could help you?.

Also the creation of a rough vacuum with the help of a pump and a suitable container would extract air from water...

Some ultrasonic cleaning devices support special degassing modes for liquid solutions (by pulse frequency variation) . Maybe degassing water by ultrasonic could help you?.

Also the creation of a rough vacuum with the help of a pump and a suitable container would extract air from water...

Some ultrasonic cleaning devices support special degassing modes for liquid solutions (by pulse frequency variation) . Maybe degassing water by ultrasonic could help you?.

Also the creation of a rough vacuum with the help of a pump and a suitable container would extract air from water...

I would assume that you don't want to add anything to the water itself (Silicone spray and other substances can be used to break the surface tension of the bubbles.) https://www.youtube.com/watch?v=6cysBCefZgA&ab_channel=Dow

Bubbles that float on water and each other (foam) are best controlled internally by lowering the liquid's surface tension. This can be done by adding alcohol or acetone or other water solubles.

Or sonic vibrations might break the foam or "floating bubbles" (or it might generate more foam. Its a two edged sword.) .https://www.sciencedirect.com/science/article/abs/pii/S1350417703001342

That said, I have another suggestion: if your bubbles are sticking to hard surfaces, make sure all surfaces that contact the material you are testing are ultra clean. Clean those surfaces with hydrophilic solvents (like alcohol or acetone), and/or hydrophobic solvents (like chlorinated hydrocarbons), they will air dry after cleaning. If appropriate, make contact with the surface while cleaning, using a hand or cloth or brush to break the Zeta potential of those surfaces. See: https://www.brookhaveninstruments.com/applications/zeta-potential/

A bubble of air "sticking" to a surface is frequently there because something else is there, a tiny "dirt" particle on the surface which "attaches to" the bubble's surface tension and keep it from moving away.

I helped develop a unique industrial grade cleaner that would probably be ideal for this. It was a mixture of both hydrophobic and hydrophilic solvents, (~1:1 ratio). The product was a clear liquid and looked like a solution, but it was actually two emulsions (water/oil and oil/water) that were competing for dominance. It was Quasi-stable and would separate at high or low temperatures and stop cleaning. When exposed to air, the product would wriggle, at random moments, for a half hour or more, it was inverting as one emulsion would "overwhelm" the other.

When thinly sprayed over various soiled surfaces, it selectively changed composition (inverted) at microscopic levels to accommodate the specific soils it encountered, and then soften those soils. Initially nothing visible happened when you sprayed it on, nothing moved, but after a few minutes even hard caked soils could be instantly rinsed away. No scrubbing required.

It left surfaces so clean that bubbles would not 'adhere' to the surfaces, no particles. And the surfaces remained cleaner much longer than other cleaning methods.

Sadly the product is no longer commercially available, primarily because it was so effective that it had a very slow turnover rate. For example one customer would buy a 4 ounce container for cleaning artists paint brushes, use it in a class, every day to clean oil and acrylic paint brushes, and then call us a year later to get another 4 ounce bottle.

Lesson learned: If a product is too good, it is not marketable. Corollary: when you solve a problem, you are out of a job. Corollary: when a doctor cures someone, they lose a patient.

Bubble, rain drop, surface tension, any chemical elements in space, and other trillions of sphere shape of moons, planets, suns in the universe is result of following of the natural law of the intrinsic universe.

Whatever you must do, it would not going to be mechanic (quantum mechanic). as old saying is "communicate with it" through another chemical elements.

I am sure you notice, my approach to solve your demand is not ordinary, thus it is not subject of peer review.

Warm the water up while purging with N2 for few minutes (for the removal of DO), then ultrasonicate it for 2-3 minutes and afterward cover it up or put it in a capped tube before use (to avoid CO2 dissolution from air). And inject slowly.