Microwave-assisted phase separation of alkali-borosilicates in the production of nanoporous glasses

• Autorzy: Kullmann J. , Enke D. , Hahn T. , Bauerschaefer U. , Ledig L. , Gai S. , Bochmann A.
• Języki publikacji: EN

Abstrakty

EN

The influence of a hybrid thermal processing on the spinodal decomposition of sodium borosilicate glasses was investigated. The pore diameter of the resulting porous glasses is a function of the parameters of the thermal treatment. One result of this study was the inversion of the phase separation under preservation of the external shape of glass monoliths. Furthermore by using microwaves in addition to thermal radiation it was possible to generate temperature gradients in the samples and so gradients in pore size too. The glass templates were heated with microwaves in a tube furnace consisting of a resonant rectangular waveguide (TE103). Additionally the tube wall was heated by thermal radiation. The heating control was realized by steering the input power and the frequency of a 200 W semiconductor source. The regulation was performed with a HOMER 3-stub tuner, which simultaneously measured the impedance by reflected wave analysis and the actual template temperature with an IR-sensor. Various temperature-time courses of the hybrid furnace led to different pore size gradients. This was discussed by analyzing specific properties like mean pore diameter, surface area and pore volume. Further effects like the pore orientation and properties of the pore walls were determined by scanning electron microscopy and focused ion beam (FIB).

Słowa kluczowe

EN

porous glasses; microwave heating

• Wydawca: Oficyna Wydawnicza Politechniki Wrocławskiej
• Czasopismo: Optica Applicata
• Rocznik: 2012
• Tom: Vol. 42, nr 2
• Strony: 255--263
• Opis fizyczny: Bibliogr. 4 poz.

Twórcy

autor

Kullmann J.

autor

Enke D.

autor

Hahn T.

autor

Bauerschaefer U.

autor

Ledig L.

autor

Gai S.

autor

Bochmann A.

• Institute of Chemical Technology, University of Leipzig, Linn?straße 3, 04103 Leipzig, Germany

Bibliografia

• [1] JANOWSKI F., ENKE D., Porous glasses, [In] Handbook of Porous Solids, Schüth F., Sing K.S.W., Weitkamp J. [Eds.], Vol. 3, Wiley-VCH, Weinheim, 2002, pp. 1432–1542.
• [2] ENKE D., JANOWSKI F., SCHWIEGER W., Porous glasses in the 21st century – A short review, Microporous and Mesoporous Materials 60(1–3), 2003, pp. 19–30.
• [3] WILLERT-PORADA M., Microwave effects on spinodal decomposition, Materials Research Society Symposium – Proceedings, Vol. 430, 1996, pp. 403–409.
• [4] ENKE D., FRIEDEL F., JANOWSKI F., HAHN T., GILLE W., MÜLLER R., KADEN H., Ultrathin porous glass membranes with controlled texture properties, Studies in Surface Science and Catalysis 144, 2002, pp. 347–354.