Synthesis and characterization of nanocrystalline mesoporous zirconia using supercritical drying.
Synthesis of nano-crystalline zirconia aerogel was done by sol-gel technique and supercritical drying using n-propanol solvent at and above supercritical temperature (235-280 degrees C) and pressure (48-52 bar) of n-propanol. Zirconia xerogel samples have also been prepared by conventional thermal drying method to compare with the super critically dried samples. Crystalline phase, crystallite size, surface area, pore volume, and pore size distribution were determined for all the samples in detail to understand the effect of gel drying methods on these properties. Supercritical drying of zirconia gel was observed to give thermally stable, nano-crystalline, tetragonal zirconia aerogels having high specific surface area and porosity with narrow and uniform pore size distribution as compared to thermally dried zirconia. With supercritical drying, zirconia samples show the formation of only mesopores whereas in thermally dried samples, substantial amount of micropores are observed along with mesopores. The samples prepared using supercritical drying yield nano-crystalline zirconia with smaller crystallite size (4-6 nm) as compared to higher crystallite size (13-20 nm) observed with thermally dried zirconia.
Tyagi
Beena
B
Silicates and Catalysis Discipline, Central Salt and Marine Chemicals Research Institute, Bhavnagar 364002, Gujarat, India.
Sidhpuria
Kalpesh
K
Shaik
Basha
B
Jasra
Raksh Vir
RV
D000433:1-Propanol; D003460:Crystallization; D005782:Gels; D006358:Hot Temperature; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods; D010316:Particle Size; D011208:Powders; D012997:Solvents; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D014961:X-Ray Diffraction; D015040:Zirconium / Q000737:chemistry*
D005782:Gels; D011208:Powders; D012997:Solvents; D000433:1-Propanol; D015040:Zirconium; C028541:zirconium oxide