Fabrication of hollow glass microspheres in the Na2O-B2O3-SiO2 system from metal alkoxides
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Abstract
Hollow glass microspheres (HGS) for laser fusion targets were fabricated in the system Na2O-B2O3-SiO2 from NaOCH3, B(OCH3)3 and Si(OC2H5)4. Gel powders prepared from metal alkoxides and urea liberate H2O, CO2 and NH3 gases, evolution of which takes place completely at about 500° C. The precursor of HGS is formed by the encapsulation of these gas components in the glass layer formed at the surface of the powder. HGS are produced from the gel powders having both a melting temperature lower than about 1000° C and a viscosity at that temperature lower than 105 P. In the Na2O-B2O3-SiO2 system, the compositions from which HGS are produced are those containing 55–75 wt% SiO2 and 0–20 wt% B2O3. HGS ranging from 100–500μm diameter and 0.5–7.0μm wall thickness are obtained by change of urea content.
Keywords
Viscosity SiO2 Urea Melting Temperature Wall ThicknessPreview
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References
- 1.C. D. Hendricks, US Patent 4133854 (1979).Google Scholar
- 2.R. G. Budrick et al., US Patent 4021253 (1977).Google Scholar
- 3.C. D. Hendricks, A. Rosencwaig, R. L. Woerner, J. C. Koo, J. L. Dressler, J. W. Sherohman, S. L. Weinland andM. Jeffries,J. Nucl. Mater. 85, 86 (1979) 107.Google Scholar
- 4.
- 5.H. E. Hagy, “Introduction to Glass Science” edited by L. D. Pye, H. J. Stevens and W. C. LaCourse (Plenum Press, New York, 1972) p. 348.Google Scholar