Preparation of Highly Transparent Silica Glass by SPS Sintering of SBA-15

Abstract

Silica glass was prepared via the spark plasma sintering (SPS) method by using SBA-15 as the starting material. Five temperatures (1000, 1010, 1020, 1030 and 1040°C) were selected as the final sintering temperature above 600°C. The transparent silica glass was prepared by SPS sintering of mesoporous silica SBA-15 at 1040°C. The impact of temperature structure collapse of SBA-15, the structure and transmittance of the glass were studied using X ray diffraction, SEM, TEM, Infrared analysis, Raman analysis and UV-VIS spectrophotometer. Results show that SBA-15 collapsed completely at 1040°C, the sintered glass had high transmittance of above 90% in visible spectra, and its hardness was 6.96 Gpa, and that the sintered transparent sample was silica glass. The work demonstrated a novel strategy to use SPS to prepare highly transparent silica glass by sintering of SBA-15.

The devitrification kinetics of transparent silica glass prepared by gel-casting method

“…The band about 794cm −1 is related to the Si-O-Si symmetric stretching vibration mode of bridging oxygen between tetrahedra [1]. The peak around 1099cm -1 was corresponding to Si-O-Si asymmetric stretching of bridging oxygen between tetrahedral of bridging oxygen within the tetrahedra [3]. The peak of the silanol (Si-OH) group at 956cm -1 and the peaks of hydroxyl group peak for H 2 O at 3440 and 1630cm -1 were not observed.…”

“…Figure 2 shows the FT-IR spectra of sample sintering at 1100°C. The peak near to 462cm −1 characterizes the bending vibration of Si-O-Si bond [3]. The band about 794cm −1 is related to the Si-O-Si symmetric stretching vibration mode of bridging oxygen between tetrahedra [1].…”

“…Many techniques have been used to prepare transparent silica glass; these include spark plasma sintering (SPS) [3][4][5], pressure less sintering [4], vapor-phase axial deposition [6,7], solid phase sintering [8,9], slip casting [10], and sol gel method [11][12][13][14][15][16]. It is well reported that the rate and mechanism of devitrification of the glasses vary with the chemical composition of the glass, temperature, ambient atmosphere, and impurities [17].…”

Hierarchically porous and mechanically stable monoliths from ordered mesoporous silica and their water filtration potential

“…COK-12's higher resilience towards sintering is furthermore supported by a higher condensation degree of the silica framework within COK-12, which is reported to increase its resistance towards compaction, 26,62 and the higher temperatures and processing times required to obtain dense structures by S-sintering. To fully eliminate the porosity in SBA-15 structures, temperatures of 900 °C, in between 930 and 980 °C, 1020 °C, and 1040 °C were reported, 22,60,63,64 being only slightly higher than the 900 °C applied to COK-12 during S-and C-sintering, resulting in porous monoliths. Hence, further parameters affecting the densification, namely pressure, dwell time, and heating rate, were reported to be the same or smaller, ensuring reasonable comparability.…”

Preparation of transparent Bi2O3‐ZnO‐B2O3 glass by conventional sintering at low temperatures

“…In the literature, the glass compositions that can achieve transparent glass components using the sintering method are mostly pure SiO 2 or predominantly composed of SiO 2 . [19][20][21][22][23][24][25][26][27][28][29][30][31][32] This is because silicate glasses usually have high glass transition temperature (T g ), excellent thermal stability, and are less prone to crystallization during sintering. On the other hand, there is limited literature on the preparation of transparent glasses of low T g by sintering method.…”