Effect of Coulombic Interactions on Rotational Mobility of Guests in Sol−Gel Silicate Thin Films
We investigate the effect of Coulombic interactions on the mobility of rhodamine 6G (R6G) and Oregon Green 514 (ORG) in sol−gel silicates by measuring their mobility distributions using single molecule polarization measurements. While R6G is a cationic dye, ORG (pK a = 3.69 ± 0.08) is an anionic dye...
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Published in | Chemistry of materials Vol. 16; no. 20; pp. 3949 - 3954 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Washington, DC
American Chemical Society
05.10.2004
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Subjects | |
Online Access | Get full text |
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Summary: | We investigate the effect of Coulombic interactions on the mobility of rhodamine 6G (R6G) and Oregon Green 514 (ORG) in sol−gel silicates by measuring their mobility distributions using single molecule polarization measurements. While R6G is a cationic dye, ORG (pK a = 3.69 ± 0.08) is an anionic dye at neutral pH. The presence of more tumbling ORG molecules in sol−gel silicates indicates that R6G and ORG experience opposite Coulombic interactions with a predominately anionic silica sol−gel surface. On the other hand, the fact that tumbling ORG only represents a minor portion of ORG investigated, even at pH 7, clearly illustrates that Coulombic interaction alone does not control the mobility of an encapsulated guest molecule in sol−gel silicates. |
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Bibliography: | ark:/67375/TPS-WFPXQS32-N istex:B17B0AEDC0387027B18C40AA6EDAE793D1D1ADD3 |
ISSN: | 0897-4756 1520-5002 |
DOI: | 10.1021/cm049250v |