Photophysical Properties of C60 Colloids Suspended in Water with Triton X-100 Surfactant: Excited-State Properties with Femtosecond Resolution

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• 作者：Andrew F. Clements ; Joy E. Haley ; Augustine M. Urbas ; Alan Kost ; R. David Rauh ; Jane F. Bertone ; Fei Wang ; Brian M. Wiers ; De Gao ; Todd S. Stefanik ; Andrew G. Mott ; David M. Mackie
• 刊名：Journal of Physical Chemistry A
• 出版年：2009
• 出版时间：June 11, 2009
• 年：2009
• 卷：113
• 期：23
• 页码：6437-6445
• 全文大小：415K
• 年卷期：v.113,no.23(June 11, 2009)
• ISSN：1520-5215

文摘

We examine the photophysics of a colloidal suspension of C₆₀ particles in a micellar solution of Triton X-100 and water, prepared via a new synthesis which allows high-concentration suspensions. The particle sizes are characterized by transmission electron microscopy and dynamic light scattering and found to be somewhat polydisperse in the range of 10−100 nm. The suspension is characterized optically by UV−vis spectroscopy, femtosecond transient absorption spectroscopy, laser flash photolysis, and z-scan. The ground-state absorbance spectrum shows a broad absorbance feature centered near 450 nm which is indicative of colloidal C₆₀. The transient absorption dynamics, presented for the first time with femtosecond resolution, are very similar to that of thin films of C₆₀ and indicate a strong quenching of the singlet excited state on short time scales and evidence of little intersystem crossing to a triplet excited state. Laser flash photolysis reveals that a triplet excited-state absorption spectrum, which is essentially identical in shape to that of molecular C₆₀ solutions, does indeed arise, but with much lower magnitude and somewhat shorter lifetime. Z-scan analysis confirms that the optical response of this material is dominated by nonlinear scattering.