Hi

What do you want to synthesize with this method? Metal oxide?

Precursors are usually metal nitrate salts as oxidizing agent, Fuel like citric acid for two purpose; fuel agent and polymerizable complexant. By ammonium nitrate or hydroxide adjusting pH of solution for control of combustion. you need beakers , Heater magnetic, electric furnace and crucible.

1st step: preparing homogeneous solution of precursors and adjusting pH (sol), heating sol to form a gel and evaporating addition solvent (gel), preheating gel in lower 500 degree or sometimes calcining as-prepared gel or powders from preheating gel for more than one hour.

You can read hand book of sol-gel science and technology by Sumio Sakka

Thank you, Arash Motevalian, I try to synthesize 1g LiMn2O4 from LiOAc and Mn(OAc)2 in a 100ml beaker, the ratio CA to total metal = 1:1. I dissolved metal salt in a desired mount of water, the CA was added and it became viscous like mud, then  I adjusted pH by NH3 to 10 and the solution was clear and orange, during the evaporation at 80oC the pH will decrease to nearly neutral so I added NH3 continually to keep pH around 9-10 but to the volume when gel formed the precipitate also appreared and I cannot get transparent gel

This my pleasure

I surprised, you want to synthesize spinel groups.

During evaporating may take place hydrolysis reaction between water and acetate ions thus pH value could be change.

Perhaps used NH4OH was dilute. You better after adding pH agent , stirring the solution and wait to set pH.

If you want to hold pH value I think you can use Buffer solution by nitric acid and its salt.

Good Luck Hoang nguyen van

Excuse me for preparing buffer solution you can use acetic acid and acetate salt 

Sorry if it's inconvenience Arash Motevalian, can I see some photos of your gel?

Yes of course

I used ammonia solution to adjust pH value to 7

Excuse me Hoang, I couldn't upload photo here thus I get you my photo link

https://www.dropbox.com/s/o6l0lxq1bf4wce7/Gel%20S10.jpg?dl=0

If you couldn't watch this photo just tell me, I'll send my photo for you

Good luck

That's very nice of you, it's interesting, thank you very much Arash Motevalian. Wish you all the best.

Your welcome Hoang

It's my pleasure

Good luck