Abstract
The spectroscopic behaviour and protolytic equilibria of fluorescein (FL) dianion immobilized in polymeric films of ethyl cellulose have been studied using fluorescence and electronic absorption spectroscopies. The absorption, excitation and emission peak maxima of the dianionic form of FL in a polymeric film of ethyl cellulose are red-shifted when compared with in aqueous medium. The bathochromic shift can be explained by hydrogen bonding effects between the dianionic form of FL and surrounding water molecules as the concentration of water in a hydrophobic polymeric film of ethyl cellulose is less. Only one single protolytic step is observed for neutral FL in polymeric membrane phase. The acid dissociation constant of FL in ethyl cellulose film is found to be 5.00-5.13 at 25°C.
| Original language | English |
|---|---|
| Pages (from-to) | 235-239 |
| Number of pages | 5 |
| Journal | Journal of Photochemistry and Photobiology A: Chemistry |
| Volume | 114 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 30 Apr 1998 |
Scopus Subject Areas
- General Chemistry
- General Chemical Engineering
- General Physics and Astronomy
User-Defined Keywords
- Ethyl cellulose
- Fluorescein dianion
- Protolytic equilibrium
- Spectroscopic behaviour