So I have ben trying to prepare TiO2 nanoparticles but i am getting trouble with the fromation of White PPT which later dissolves to form a clear solution that unfortunately doesnt form a gel. it remains in liquid state for days. What could be the problem. i have been using TTIP:ISOPROPANOL: WATER ratio of 1:10:15. and 3ml of NHO3 acid. someone please help.
Hey there Diana Cherop,
Sounds like you're experiencing some frustration with your TiO2 nanoparticle synthesis, huh? Let me see if I can help you Diana Cherop troubleshoot this.
When you Diana Cherop add a solution of nitric acid and water to a solution of TTIP in isopropanol, the rapid formation of a white precipitate could be due to the hydrolysis of titanium isopropoxide (TTIP) in the presence of water. This reaction forms titanium hydroxide, which precipitates out of solution.
Now, regarding the formation of a clear solution after the initial white precipitate dissolves, followed by the failure to form a gel, there are a few factors we need to consider:
1. **Hydrolysis of TTIP**: The initial white precipitate you Diana Cherop observe is likely titanium hydroxide, formed due to the hydrolysis of TTIP. However, this precipitate can redissolve in acidic conditions, leading to a clear solution.
2. **Gel Formation**: The formation of a gel typically requires the aggregation or cross-linking of nanoparticles. If your solution remains in a liquid state for days without forming a gel, it suggests that the nanoparticles are not aggregating or cross-linking effectively.
Possible reasons for this could include:
- Inadequate concentration of TTIP: Increasing the concentration of TTIP may promote nanoparticle aggregation.
- Insufficient acid concentration: The addition of nitric acid serves to catalyze the hydrolysis and condensation reactions necessary for gel formation. You Diana Cherop may need to adjust the amount of nitric acid added.
- Incorrect solvent ratio: The ratio of TTIP to isopropanol to water could affect the nanoparticle formation. Experimenting with different ratios might improve gel formation.
3. **Stability Issues**: Even if nanoparticles are formed, their stability in solution can affect gel formation. Factors such as pH, solvent choice, and surface chemistry can influence nanoparticle stability.
In summary, to address your issue, consider optimizing the TTIP concentration, adjusting the acid concentration, and experimenting with different solvent ratios. Additionally, ensure proper control of reaction conditions to promote nanoparticle aggregation and gel formation.
Hope this helps you Diana Cherop get back on track with your nanoparticle synthesis! Let me know if you Diana Cherop need further assistance.
Thank you so much Kaushik Shandilya for this. I definitely need to do more experimenting.
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