A study of the dependence of the bulk etch rate and the reduced etch rate on the concentration of etched products of Lexan

Abstract

Measurements of the bulk etch rate, υ g, for etching solutions with concentrations of Lexan etched products, x, ranging from 0 to 7.8 g/l showed the existence of an initial region where υ g increases with x; and a second region, for concentrations above approximately 2.15 g/l, where υ g no longer depends on x. The division between these two regions (≅2.15 g/l) did not coincide with the concentration of solubility saturation, found to be at 1.51 g/l. Tracks from relativistic gold ions (with kinetic energies between 10.3 and 10.6 GeV/u) were used to measure the reduced etch rate ( S, the ratio between the track etch rate, υ t, and υ g) for three etching solutions with different concentrations of etched products (0.052, 1.81 and 7.8 g/l); the values obtained for the first two concentrations were compatible with each other (3.95 ± 0.16 and 3.85 ± 0.14), whereas the reduced etch rate corresponding to the concentration of 7.8 g/l of etched products was significantly different; 4.68 ± 0.14.