Accession Number : ADA266277


Title :   Structural Studies of Sol-Gel Glasses


Descriptive Note : Final rept. 15 Jul 1989-14 Jul 1992


Corporate Author : BRUNEL UNIV UXBRIDGE (UNITED KINGDOM)


Personal Author(s) : Perry, Carole C


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a266277.pdf


Report Date : 14 Jul 1992


Pagination or Media Count : 8


Abstract : Near and Mid infrared spectroscopy and FT-Raman spectroscopy have been used to study silica/titania monoliths produced by the sol-gel route which have been subjected to selected heat treatments. Increasing thermal treatment temperature leads to a general strengthening of the gel-glass matrix although the incorporation of low levels (3% by weight) of titanium into tetrahedral sites only, led to more disordered glasses than for silica alone. Evidence has been obtained for the formation of Si-O-Ti bonds principally during the later stages of densification at temperatures between 615 and 1000 deg C. The addition of titanium also leads to a reduction in surface 'free' silanol levels together with an increase in hydrogen bonded silanol levels and increasing amounts of water associated with the glass. The implication is that the incorporation of titanium onto the surface of the gel matrix leads to tighter binding of water molecules to silanol groups.


Descriptors :   *INFRARED SPECTROSCOPY , *GELS , *TITANIUM COMPOUNDS , *SILICA GLASS , THERMAL PROPERTIES , FOURIER TRANSFORMATION , WATER , OPTICAL MATERIALS , HEAT TREATMENT , OXYGEN , POROUS MATERIALS , MOLECULAR STRUCTURE , CHEMICAL BONDS , SURFACES , HYDROGEN , RAMAN SPECTROSCOPY , MOLECULES , DENSITY


Subject Categories : Physical Chemistry
      Ceramics, Refractories and Glass
      Atomic and Molecular Physics and Spectroscopy


Distribution Statement : APPROVED FOR PUBLIC RELEASE