If you're doing a sovlent casted film Ive gotten the bubbles out a few ways. One is that you'll probably need to reduce the viscosity of the solution and let it stand. but if you're able to get a bubble-less solution and you cast a film, by slowing the evaportation rate you can stop bubbles from forming in your film. So if you cover the casted film, do it on a cold surface or chill the polymer solution you can reduce the evaportation rate.

Hi! Alex, if I make less viscous solution than the cold flow will be high when I will put the gel on casting surface. Moreover, in my formulation solvent is water and I am evaporating water at 60 C. Moreover, I put the gel in sonicator for 5 hrs and still I am getting air bubbles.

Thank you

When you have a viscous polymer, air is included when you stir your polymer. The more vigorous the mixing, the higher amount of air included.

One method to prevent from bubbling inclusion is the coupled increase in mixing temperature (to reduce viscosity) and vacuum mixing.

When you extract bubbles from a batch, you can try to apply repeated vacuum cycles followed by fast re-pressurization. This can help in removing superficial bubbles or internal visible bubbles. This procedure is less effective on micro-bubbles.

Polymer pot life must be considered since bubbling removal can take time (even hours, depending on compound viscosity) and higher mixing temperature increases your curing kinetics.

work hard on viscosity , vacuum system and temperature

Hi modi,

1) Have you kept your solution overnight after sonication. it helps to remove bubbles.

2) Try to make your solution a bit less viscous.

3) Repeated vacuum cycles also helps to remove bubbles.

4) More stirring also incorporates more air bubbles, so decrease the stirring speed       and stirring time while preparing.

hope you will get good results,

first: u can try use the ultrasonic divice to remove the bubbles;

second: u can try useing the method of centrifugal to remove the bubbles;

Hi

1) you can use ultrasonic

2) you can use special additives (BYKs for exampel)

hi i am making polymeric PVDF+TEF  membranes by non-solvent induced phase separation. By looking the dope solution is not having any air bubbles. But during casting and and immersing in coagulation bath lot of air small and micro bubbles appearing.  How to avoid these bubbles.?

Thank you all. Your comments helped my work too

try using a centrifuge

the more viscous the solution results in more tiny bubble formation , so try to minimize the entry of air by covering it with foil till you poured.

Those interested at this query topic may possibly want to check also this related RG discussion: https://www.researchgate.net/post/How_can_I_avoid_the_formation_of_air_bubbles_when_hydrogels_are_made_by_gamma_irradiation_technique

I'm not sure this is still relevant, however, Thinky mixer is very good at removing air bubbles from gels and solutions. You can find several models in their website, here: https://www.thinkymixer.com/en-gl/

Good luck

You can try stirring at a slower speed and lower temperature.

Hello!!

Could you please help me to tell me how to remove air bubbles from the gel. Actually, I prepare the gel by mixing the solution with two syringes and this will make bubble during the gel formation. I have tried the vaccum and the centrifugation process and nothing was working!!

Thank you for your help

Hi Maya

I recommend,

1. Reduce the stirring speed of the solution.

2. Reduce stirring time as well.

3. Optimize the concentration as well, the concentration is probably higher than normal.

4. You can incubate overnight at 4 ° C. It is better if the plate door is open.

Good luck

SHK

Use inhibitors in this so that the solution gets more time to free from bubbles instead of having catalyst

Dear Fauzen , what do you mean by inhibitors? can you tell the name of on sample?

did you try UV light or heat treatment (30C) or together under vacuum ?