Optical anisotropy of absorbing particles: Light scattering depolarization, electric- and flow birefringence and dichroism of suspensions of carbon blacks

The use of a rather: elongated spheroid, the compacity of which decreases with its weight, equivalent to the aggregates allows to explain the effects of depolarized light scattering and of birefringence. In particular, a very unusual negative macroform birefringence has been found. Moreover the theoretical expressions concerning the absorbing particles which simultaneously exhibit an electric dichroism and birefringence have been written. They were tested by means of suspensions of carbon blacks.