Details
| Original language | English |
|---|---|
| Pages (from-to) | 176-189 |
| Number of pages | 14 |
| Journal | Glass Science and Technology |
| Volume | 76 |
| Issue number | 4 |
| Publication status | Published - Jul 2003 |
Abstract
Water-related IR absorption bands were investigated in hydrous soda-lime-silica glass (SLS) and float glass (FG). Glasses containing between 0.5 and 6 wt% H2O (corresponding to 0.7 and 8 mol/l) were synthesized in platinum capsules by re-melting glass powder to which water had been added. Synthesis were performed in an internally heated gas pressure vessel at temperatures of 1200 to 1250°C and pressures 100 to 500 MPa. The total water content (Cwater) of glasses was analyzed by pyrolysis and subsequent Karl-Fischer titration. Five bands at 3550, 2850, 2350, 1730, and 1635 cm-1 in the IR spectrum of an SLS glass containing 4 wt% H2O were identified as vibration modes of water-related species by comparison with a D2O-bearing glass. With increasing Cwater, the absorbance band at 3550 cm-1 (OH stretch of weakly H-bonded hydrous species) grows in intensity relative to the band at 2850 cm-1 (OH stretch of strongly H-bonded hydrous species). As a consequence, the practical absorption coefficient for the band at 3550 cm-1 (ε3550pract, defined by assigning the total water to this band) is 20% lower at 0.1 wt% water than at 4 wt% water. The dependence of ε3550pract on Cwater is most pronounced above 0.5 wt% but appears to be present also in water-poor glasses. In contrast, ε2850pract does not noticeably depend on water content (FG: ε2850pract = (40.2 ± 2.4) l·mol-1·cm-1; SLS: ε2850pract = (50.8 ± 2.0) l·mol-1·cm-1) and, hence, it is preferred for water determination in float glass and soda-lime-silica glass. Scholze's two-band method [1] using the peak height of both bands at 3550 and 2850 cm-1 to quantify Cwater in glasses is a suitable first approach also for hydrous glasses, predicting the water content within 20% relative. However, for a more precise determination the dependence of the ε-values on Cwater has to be considered. A preliminary evaluation of the H2O bending vibration band at 1635 cm-1 shows that molecular H2O is a minor hydrous species in FG and SLS glasses with a maximum concentration of 2.0 wt% in FG glass containing 5.7 wt% total water. On the basis of the new spectroscopic results and data from literature the assignment of the so-called ABS triplet (bands 2850, 2350 and 1750 cm-7 cm-1) is discussed.
ASJC Scopus subject areas
- Materials Science(all)
- Ceramics and Composites
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: Glass Science and Technology, Vol. 76, No. 4, 07.2003, p. 176-189.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Quantification of H2O contents in silicate glasses using IR spectroscopy - A calibration based on hydrous glasses analyzed by Karl-Fischer titration
AU - Behrens, Harald
AU - Stuke, Alexandra
PY - 2003/7
Y1 - 2003/7
N2 - Water-related IR absorption bands were investigated in hydrous soda-lime-silica glass (SLS) and float glass (FG). Glasses containing between 0.5 and 6 wt% H2O (corresponding to 0.7 and 8 mol/l) were synthesized in platinum capsules by re-melting glass powder to which water had been added. Synthesis were performed in an internally heated gas pressure vessel at temperatures of 1200 to 1250°C and pressures 100 to 500 MPa. The total water content (Cwater) of glasses was analyzed by pyrolysis and subsequent Karl-Fischer titration. Five bands at 3550, 2850, 2350, 1730, and 1635 cm-1 in the IR spectrum of an SLS glass containing 4 wt% H2O were identified as vibration modes of water-related species by comparison with a D2O-bearing glass. With increasing Cwater, the absorbance band at 3550 cm-1 (OH stretch of weakly H-bonded hydrous species) grows in intensity relative to the band at 2850 cm-1 (OH stretch of strongly H-bonded hydrous species). As a consequence, the practical absorption coefficient for the band at 3550 cm-1 (ε3550pract, defined by assigning the total water to this band) is 20% lower at 0.1 wt% water than at 4 wt% water. The dependence of ε3550pract on Cwater is most pronounced above 0.5 wt% but appears to be present also in water-poor glasses. In contrast, ε2850pract does not noticeably depend on water content (FG: ε2850pract = (40.2 ± 2.4) l·mol-1·cm-1; SLS: ε2850pract = (50.8 ± 2.0) l·mol-1·cm-1) and, hence, it is preferred for water determination in float glass and soda-lime-silica glass. Scholze's two-band method [1] using the peak height of both bands at 3550 and 2850 cm-1 to quantify Cwater in glasses is a suitable first approach also for hydrous glasses, predicting the water content within 20% relative. However, for a more precise determination the dependence of the ε-values on Cwater has to be considered. A preliminary evaluation of the H2O bending vibration band at 1635 cm-1 shows that molecular H2O is a minor hydrous species in FG and SLS glasses with a maximum concentration of 2.0 wt% in FG glass containing 5.7 wt% total water. On the basis of the new spectroscopic results and data from literature the assignment of the so-called ABS triplet (bands 2850, 2350 and 1750 cm-7 cm-1) is discussed.
AB - Water-related IR absorption bands were investigated in hydrous soda-lime-silica glass (SLS) and float glass (FG). Glasses containing between 0.5 and 6 wt% H2O (corresponding to 0.7 and 8 mol/l) were synthesized in platinum capsules by re-melting glass powder to which water had been added. Synthesis were performed in an internally heated gas pressure vessel at temperatures of 1200 to 1250°C and pressures 100 to 500 MPa. The total water content (Cwater) of glasses was analyzed by pyrolysis and subsequent Karl-Fischer titration. Five bands at 3550, 2850, 2350, 1730, and 1635 cm-1 in the IR spectrum of an SLS glass containing 4 wt% H2O were identified as vibration modes of water-related species by comparison with a D2O-bearing glass. With increasing Cwater, the absorbance band at 3550 cm-1 (OH stretch of weakly H-bonded hydrous species) grows in intensity relative to the band at 2850 cm-1 (OH stretch of strongly H-bonded hydrous species). As a consequence, the practical absorption coefficient for the band at 3550 cm-1 (ε3550pract, defined by assigning the total water to this band) is 20% lower at 0.1 wt% water than at 4 wt% water. The dependence of ε3550pract on Cwater is most pronounced above 0.5 wt% but appears to be present also in water-poor glasses. In contrast, ε2850pract does not noticeably depend on water content (FG: ε2850pract = (40.2 ± 2.4) l·mol-1·cm-1; SLS: ε2850pract = (50.8 ± 2.0) l·mol-1·cm-1) and, hence, it is preferred for water determination in float glass and soda-lime-silica glass. Scholze's two-band method [1] using the peak height of both bands at 3550 and 2850 cm-1 to quantify Cwater in glasses is a suitable first approach also for hydrous glasses, predicting the water content within 20% relative. However, for a more precise determination the dependence of the ε-values on Cwater has to be considered. A preliminary evaluation of the H2O bending vibration band at 1635 cm-1 shows that molecular H2O is a minor hydrous species in FG and SLS glasses with a maximum concentration of 2.0 wt% in FG glass containing 5.7 wt% total water. On the basis of the new spectroscopic results and data from literature the assignment of the so-called ABS triplet (bands 2850, 2350 and 1750 cm-7 cm-1) is discussed.
UR - http://www.scopus.com/inward/record.url?scp=0141522783&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:0141522783
VL - 76
SP - 176
EP - 189
JO - Glass Science and Technology
JF - Glass Science and Technology
SN - 0946-7475
IS - 4
ER -