- Library Home /
- Search Collections /
- Open Collections /
- Browse Collections /
- UBC Undergraduate Research /
- Variations in wetting angles for carbonate-silicate...
Open Collections
UBC Undergraduate Research
Variations in wetting angles for carbonate-silicate melts Huang, Katherine
Abstract
The sessile drop method was used to measure the wetting angles of carbonate-silica melt droplets as a proxy for surface tension. Melts were synthesized by sintering pure anhydrous Na₂CO₃ powder with SiO₂ powder. The final weight percentages of Na₂O, SiO₂, and CO₂ of each melt were calculated. Samples of approximately 0.03g of each melt composition were melted on a substrate of alumina at 1000°C until the droplets had fully relaxed. The droplets were quenched at room temperature and wetting angle measurements were taken. Droplets of melt compositions of 62 wt% SiO2 and less produced wetting angles of 3 to 9°. Droplets of melt composition of 71 wt% produced drastically higher wetting angles of 23°. These results indicate that SiO₂ content does not significantly affect the wetting angle of the Na₂SiO₃- SiO₂ system until SiO₂ composes 71 wt% of the of the melt composition. The phase diagram of the SiO₂-Na₂CO₃ system is used to estimate the varying amounts of liquid and solid Na₂CO₃, solid Na₂SiO₃, liquid Na₂Si₂O⁰₅, and solid SiO₂ in each melt. Due to its molecular structure and high number of non-bridging oxygens/tetrahedral (NBO/T) Na₂CO₃ likely is the controlling component of the surface tension of the melts below 71 wt% SiO₂. Once the melt composition exceeds 62 wt% SiO₂,, Na₂Si₂O₅ controls the surface tension of the melt via the introduction of a bridging oxygen that affects the interactions between the liquid molecules and increases the wetting angle.
Item Metadata
Title |
Variations in wetting angles for carbonate-silicate melts
|
Creator | |
Date Issued |
2014-03
|
Description |
The sessile drop method was used to measure the wetting angles of carbonate-silica melt
droplets as a proxy for surface tension. Melts were synthesized by sintering pure anhydrous
Na₂CO₃ powder with SiO₂ powder. The final weight percentages of Na₂O, SiO₂, and CO₂ of each
melt were calculated. Samples of approximately 0.03g of each melt composition were melted on
a substrate of alumina at 1000°C until the droplets had fully relaxed. The droplets were quenched
at room temperature and wetting angle measurements were taken. Droplets of melt compositions
of 62 wt% SiO2 and less produced wetting angles of 3 to 9°. Droplets of melt composition of 71
wt% produced drastically higher wetting angles of 23°. These results indicate that SiO₂ content
does not significantly affect the wetting angle of the Na₂SiO₃- SiO₂ system until SiO₂ composes
71 wt% of the of the melt composition. The phase diagram of the SiO₂-Na₂CO₃ system is used to
estimate the varying amounts of liquid and solid Na₂CO₃, solid Na₂SiO₃, liquid Na₂Si₂O⁰₅, and
solid SiO₂ in each melt. Due to its molecular structure and high number of non-bridging
oxygens/tetrahedral (NBO/T) Na₂CO₃ likely is the controlling component of the surface tension
of the melts below 71 wt% SiO₂. Once the melt composition exceeds 62 wt% SiO₂,, Na₂Si₂O₅
controls the surface tension of the melt via the introduction of a bridging oxygen that affects the
interactions between the liquid molecules and increases the wetting angle.
|
Genre | |
Type | |
Language |
eng
|
Series | |
Date Available |
2015-09-08
|
Provider |
Vancouver : University of British Columbia Library
|
Rights |
Attribution-NonCommercial-NoDerivs 2.5 Canada
|
DOI |
10.14288/1.0053618
|
URI | |
Affiliation | |
Campus | |
Peer Review Status |
Unreviewed
|
Scholarly Level |
Undergraduate
|
Rights URI | |
Aggregated Source Repository |
DSpace
|
Item Media
Item Citations and Data
Rights
Attribution-NonCommercial-NoDerivs 2.5 Canada