1 / 14

Sol-Gel

Sol-Gel. Why Sol-Gel..?. -. What’s Sol-Gel.. . Process in which solid nano particles are dispersed in a liquid (a sol) and agglomerate together to form a continuous three-dimensional network extending throughout the liquid (a gel) Involves hydrolysis and poly-condensation. Sol-Gel.

rafi
Download Presentation

Sol-Gel

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Sol-Gel

  2. Why Sol-Gel..? -

  3. What’s Sol-Gel.. • Process in which solid nano particles are dispersed in a liquid (a sol) and agglomerate together to form a continuous three-dimensional network extending throughout the liquid (a gel) • Involves hydrolysis and poly-condensation

  4. Sol-Gel.. • Solid particles (up to few 100 nm) suspended in liquid phase i.e. Sol • Solid macromolecule (polymer chains) immersed in liquid phase i.e. Gel • Particles in Sol condense in new phase Gel

  5. Precursors: Metal alkoxides and metal chlorides(as they readily react with water) e.g. TEOS • Colloid contain broad range of solid(or liquid) particles dispersed in various degrees in liquid. • Sedimentation and centrifugation • Drying and firing

  6. Sol-Gel synthesis: …consists of hydrolysis and condensation. Hydrolysis: M(OR)x+ H2O → HO-M(OR)x-1+ R-OH R: -CH3, -C2H5 etc. M:Si, Al, Ti etc.

  7. Condensation: 1. Alcohol condensation: (OR)x-1-MOH + ROM-(OR)x-1→ (RO)x-1-MOM-(OR)x-1 + ROH 2. Water condensation: (OR)x-1-MOH + HOM-(OR)x-1→ (RO)x-1-MOM-(OR)x-1 + HOH

  8. Sol-Gel for TEOS TEOS AND WATER TEOS polymerization

  9. Sol-Gel technologies…

  10. Factors affecting Sol-Gel • Variation of gelation time with PH

  11. As the temperature increases the gelation time decreases.

  12. Applications… • Synthesis of ceramics, glass, fibres • Thin films on substrate • Nuclear fuels (UO2 and ThO2) • Aerogels and xerogels • Optical and refractory ceramic fibers • Zeolite synthesis • Powder abrasives • Optical coating, protective coating on plastic, glass, metals • BaTiO3electronic material for capacitors

  13. Advantages: • Cheap and low temp. operation • Very thin films of metal oxides can be obtained • Uniform distribution of components and porosity • Better alternative approach to conventional production of glasses • Easy dopant addition in ceramics processing • Sol gel material can be obtained as bulks, thin films, (nano) powders

  14. Thank You By Sai Charan

More Related