Details
| Originalsprache | Englisch |
|---|---|
| Seiten (von - bis) | 30-39 |
| Seitenumfang | 10 |
| Fachzeitschrift | Journal of Non-Crystalline Solids |
| Jahrgang | 497 |
| Frühes Online-Datum | 28 Mai 2018 |
| Publikationsstatus | Veröffentlicht - 1 Okt. 2018 |
Abstract
Borosilicate glasses (16Na2O–10B2O3–74SiO2, NBS) with water contents up to 22 mol% H2O were prepared to study the effect of water on structural relaxation using DTA, viscometry and internal friction measurements. The results show that the glass transition temperature Tg of DTA and the isokom temperature T12, of viscometry are in excellent agreement, confirming the equivalence of enthalpy and viscous relaxation for NBS glass. Combining Tg data with water speciation data demonstrates that OH groups are mainly responsible for the decrease of Tg with increasing hydration, while molecular water plays only a minor role. Internal friction spectra at 7.125 Hz confirm the decisive influence of water on mechanical relaxation. The temperature range of α-relaxation (glass transition) strongly decreases while two β-relaxation peaks (sub-Tg) progressively appear with increasing water content. A high temperature β-relaxation peak, attributed to the presence of OH groups, shifts from 670 to 450 K as total water content increases from 0.01 to 5 wt%. A low temperature β-relaxation peak, attributed to molecular water, appears at 380 K and 330 K in glasses containing 3 and 5 wt% H2O, respectively. These findings suggest that relaxation mechanism of different hydrous species at low temperature may contribute to fatigue of stressed glasses.
ASJC Scopus Sachgebiete
- Werkstoffwissenschaften (insg.)
- Elektronische, optische und magnetische Materialien
- Werkstoffwissenschaften (insg.)
- Keramische und Verbundwerkstoffe
- Physik und Astronomie (insg.)
- Physik der kondensierten Materie
- Werkstoffwissenschaften (insg.)
- Werkstoffchemie
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in: Journal of Non-Crystalline Solids, Jahrgang 497, 01.10.2018, S. 30-39.
Publikation: Beitrag in Fachzeitschrift › Artikel › Forschung › Peer-Review
}
TY - JOUR
T1 - Structural relaxation mechanisms in hydrous sodium borosilicate glasses
AU - Behrens, H.
AU - Bauer, Ute
AU - Reinsch, S.
AU - Kiefer, P.
AU - Müller, R.
AU - Deubener, J.
N1 - © 2018 Elsevier B.V. All rights reserved.
PY - 2018/10/1
Y1 - 2018/10/1
N2 - Borosilicate glasses (16Na2O–10B2O3–74SiO2, NBS) with water contents up to 22 mol% H2O were prepared to study the effect of water on structural relaxation using DTA, viscometry and internal friction measurements. The results show that the glass transition temperature Tg of DTA and the isokom temperature T12, of viscometry are in excellent agreement, confirming the equivalence of enthalpy and viscous relaxation for NBS glass. Combining Tg data with water speciation data demonstrates that OH groups are mainly responsible for the decrease of Tg with increasing hydration, while molecular water plays only a minor role. Internal friction spectra at 7.125 Hz confirm the decisive influence of water on mechanical relaxation. The temperature range of α-relaxation (glass transition) strongly decreases while two β-relaxation peaks (sub-Tg) progressively appear with increasing water content. A high temperature β-relaxation peak, attributed to the presence of OH groups, shifts from 670 to 450 K as total water content increases from 0.01 to 5 wt%. A low temperature β-relaxation peak, attributed to molecular water, appears at 380 K and 330 K in glasses containing 3 and 5 wt% H2O, respectively. These findings suggest that relaxation mechanism of different hydrous species at low temperature may contribute to fatigue of stressed glasses.
AB - Borosilicate glasses (16Na2O–10B2O3–74SiO2, NBS) with water contents up to 22 mol% H2O were prepared to study the effect of water on structural relaxation using DTA, viscometry and internal friction measurements. The results show that the glass transition temperature Tg of DTA and the isokom temperature T12, of viscometry are in excellent agreement, confirming the equivalence of enthalpy and viscous relaxation for NBS glass. Combining Tg data with water speciation data demonstrates that OH groups are mainly responsible for the decrease of Tg with increasing hydration, while molecular water plays only a minor role. Internal friction spectra at 7.125 Hz confirm the decisive influence of water on mechanical relaxation. The temperature range of α-relaxation (glass transition) strongly decreases while two β-relaxation peaks (sub-Tg) progressively appear with increasing water content. A high temperature β-relaxation peak, attributed to the presence of OH groups, shifts from 670 to 450 K as total water content increases from 0.01 to 5 wt%. A low temperature β-relaxation peak, attributed to molecular water, appears at 380 K and 330 K in glasses containing 3 and 5 wt% H2O, respectively. These findings suggest that relaxation mechanism of different hydrous species at low temperature may contribute to fatigue of stressed glasses.
KW - Borosilicate glasses
KW - Glass transition
KW - Internal friction
KW - Relaxation
KW - Water
UR - http://www.scopus.com/inward/record.url?scp=85047449600&partnerID=8YFLogxK
U2 - 10.1016/j.jnoncrysol.2018.05.025
DO - 10.1016/j.jnoncrysol.2018.05.025
M3 - Article
AN - SCOPUS:85047449600
VL - 497
SP - 30
EP - 39
JO - Journal of Non-Crystalline Solids
JF - Journal of Non-Crystalline Solids
SN - 0022-3093
ER -