Fluorimetric Study of Electron Donor−Acceptor Complex Formation of Asphaltene with o- and p-Chloranil

详细信息    查看全文

• 作者：Ashish Kumar Ghosh ; Sanjib Bagchi
• 刊名：Energy & Fuels
• 出版年：2008
• 出版时间：May 2008
• 年：2008
• 卷：22
• 期：3
• 页码：1845 - 1850
• 全文大小：127K
• 年卷期：v.22,no.3(May 2008)
• ISSN：1520-5029

文摘

Steady-state fluorescence spectra of coal derived asphaltenes sourced from the Barari coke plant situated in Dhanbad, India, have been studied in carbon tetrachloride solution. Quenching of the asphaltene fluorescence in solutions containing fixed concentrations of asphaltene (10 and 0.05 mg/L) has been studied in the presence of the two isomeric chloranils. Quenching has also been studied by varying the excitation wavelength. Time-resolved fluorescence studies indicate that the average lifetime of asphaltene in the excited-state remains unaltered in the presence of the quencher, indicating static quenching involving ground-state complexation of asphaltene with the chloranils. The value of the average lifetime does not depend on the concentration of asphaltene in the concentration range studied. The equilibrium constant (K) for the formation of the electron donor–acceptor complex has been determined from Stern−Volmer plots. The dependence of the K values on the excitation and emission wavelengths and also on the concentration of asphaltene in the solution has been studied.