Visible spectra of fractal particles in colloidal solutions

The visible spectra of fractal colloidal particles are analysed. The considerable broadening of the light absorption peak for colloidal solutions is supposed to be due to additional oscillatory degrees of freedom arising in a fractal cluster. The shape of the low-frequency edge of the absorption peak is shown to obey the following formula: I(λ) ∝ λ−D, where I is the intensity of the absorbed light, λ is the wavelength and D is the fractal dimension of the particles in colloidal solution.