The Effect of pH on the Fluorescence Properties of Thermally Stable CMC/Eu complexes

摘要

CMC/Eu complexes were synthesized in different pH values by reacting with Eu~(3+) and CMC, a kind of biodegradable polymer. FT-IR results confirmed that, on CMC chains, carboxyl groups and the oxygen atom of unsubstituted hydroxyl groups and ether bonds were all involved in the reaction with Eu~(3+). TG analysis showed that CMC/Eu complexes were thermally stable in a wide temperature range from 30 to 300°C. The emission intensity decreased when the pH value increased from 7.0 to 12.0. However, at pH=12, because that the extent of reaction of Eu~(3+) and CMC decreased and CMC degraded, the complexes had a weak fluorescence intensity.