THERMAL LENS STUDY OF THE ABSORBENCY OF SILVER COLLOID SOLUTIONS PRODUCED BY PHOTOREDUCTION

The absorption of light by photolytically generated silver colloid sol utions is studied by thermal lens spectrophotometry. It is found that absorbance by silver nitrate solutions at 488 nm is a result of colloi d formation. The absorbance is related to the particle size distributi on and varies substantially from measurement to measurement even withi n the same colloidal solution. The shot-to-shot variance of the therma l lens signal is minimized by producing the colloid in a flowing AgNO3 solution, but still varies significantly from solution to solution at equal concentrations.