Light Scattering Study on Sol-Gel Transformation of SiO 2 Colloid at Extremely High Concentrations
Abstract Ludox SiO 2 sols with a reasonably uniform size of 12 nm and in the high concentration of 10 to 40 wt% were transformed to gels by lowering the pH. The process from sol to gel, followed by light scattering, did not show a sign of fractal growth within the length scale of observation (>0...
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| Published in | Clays and clay minerals Vol. 46; no. 2; pp. 161 - 166 |
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| Main Authors | , |
| Format | Journal Article |
| Language | English |
| Published |
01.04.1998
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| Online Access | Get full text |
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| Summary: | Abstract
Ludox SiO
2
sols with a reasonably uniform size of 12 nm and in the high concentration of 10 to 40 wt% were transformed to gels by lowering the pH. The process from sol to gel, followed by light scattering, did not show a sign of fractal growth within the length scale of observation (>0 nm). Rather, a density fluctuation due to a dynamic (non-equilibrium) disorder was apparent. Together with the results of viscosity measurements, it was concluded that the process consists of 3 stages: 1) A dynamic (non-equilibrium) density fluctuation grows rapidly. 2) Such density fluctuation acquires some order. 3) The entire bulk loses fluidity and becomes a macroscopic gel. |
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| ISSN: | 0009-8604 1552-8367 |
| DOI: | 10.1346/CCMN.1998.0460206 |