Sol-gel synthesis and structure of cordierite/tialite glass-ceramics

Abstract

In the present work the results of the research on the sol-gel synthesis and structure of cordierite (2MgO?2Al2O3?5SiO2), tialite (Al2O3?TiO2) and cordierite/tialite glass-ceramics as well cordierite containing 2 wt.% of Co and Co+Cu have been described and discussed. The sol-gel synthesis was carried out using different kind of precursors as follows: Al(NO3)?9H2O, Si(OC2H5)4, Ti(OC4H9)4, Mg(NO3)2?6H2O, chlorides or nitrates of corresponding metals, H2O, C2H5OH, Aqua Regia, NH4F and PEG. The synthesized gels were dried and thermally treated in the temperature range from 800?C to 1200?C. The sol-gel processes and structure of the cordierite, tialite and cordierite/tialite glass-ceramics have been investigated by means of XRD, FTIR, TEM, SEM and EPMA. .

Processing and characterization of pure cordierite and zirconia-doped cordierite ceramic composite by precipitation technique

“…24 The absorption band at 740 cm −1 corresponds to the stretched vibration modes of Al-O and Mg-O bonds. 25 The spectra of the powder heat treated at 1200 • C correspond to a mixture of solid solution and spinel phase. The existence On further heating at 1200 • C, the band at 780 cm −1 corresponding to the ring structure of the SiO 4 tetrahedron appears.…”

Effects of Nd2O3 Doping Levels on the Sintering, Microstructures, and Dielectric Properties of MgO–Al2O3–SiO2 Glass‐Ceramics

“…El-Buaishi et al [21] assigned the band at 770 cm À1 to the tetrahedral hexahedral rings of α-cordierite. In addition, Radev et al [22] assigned the band at 580 cm À1 to octahedral vibrations of MgO 6 and moieties band at 950 cm À1 to the Al─O bonds of tetrahedral AlO 4 . [20,21] The band at 480 cm À1 was associated with the Si─O bond vibrations of α-cordierite.…”

Structural and optical properties of cordierite glass-ceramic doped in polyurethane matrix

“…26,27 This is while a wide band from 1100 to 1200 cm −1 (1105 cm −1 ) corresponds to the presence of SiO 4 tetrahedra in cordierite; since by adding of cordierite compounds into PU, the intensity of bands assigned to SiO 4 tetrahedra starts to decrease. 28 A possible explanation for this observation can be higher number of reactions between cordierite and PU at higher amounts of cordierite in the polymer matrix.…”