Sol-gel and ultrafine particle formation via dielectric tuning of inorganic salt-alcohol-water solutions
In this work, the formation of monodispersed hydrous zirconia microsphere particles (particularly nanosized) and gels was achieved in solutions of zirconyl chloride dissolved in alcohol-water mixed solvents. A lower dielectric constant of mixed solvent corresponds to a lower solubility of inorganic solute and, thus, a shorter induction period for nucleation as well as higher solid particle growth kinetics. The sol-gel processes in the mixed solvent system can be adjusted using the processing parameters, including the initial inorganic salt concentration (C), alcohol/aqueous medium volume ratio of the mixed solution (RH), incubation temperature (T), incubation time (t), concentration of hydroxypropyl cellulose (HPC), and ammonia neutralization. Monodispersed submicron and nanoscale (<100 nm) zirconia microspheres/powders were successfully synthesized under conditions of high RH (5) and using HPC (molecular weight of 100,000, 2.0 x 10{sup {minus}3} g/cm{sup 3}) and ammonia neutralization. Initial salt concentration affects the particle size significantly. Gel materials were obtained under conditions of low RH (1.0). Microstructure and transparency of gels changed significantly from low (0.05 M) to high (0.2 M) concentration of the metal salt. The authors have also demonstrated that monodispersed particle production can be achieved not only at low temperatures (<100 C) but also at room temperature using an inorganic salt precursor.
- Research Organization:
- Oak Ridge National Lab., TN (US)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-96OR22464
- OSTI ID:
- 20017490
- Journal Information:
- Journal of Colloid and Interface Science, Vol. 222, Issue 1; Other Information: PBD: 1 Feb 2000; ISSN 0021-9797
- Country of Publication:
- United States
- Language:
- English
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