Facile Fabrication, Structures, and Properties of Laser-Marked Polyacrylamide/Bi2O3 Hydrogels : Laser-Marked Polyacrylamide/Bi2O3 Hydrogels

Laser marking of wet and soft polyacrylamide/bismuth oxide (PAM/Bi2O3) hydrogel materials can be achieved by simply embedding Bi2O3 particles inside PAM hydrogels and a subsequent laser treatment with a Nd: YAG laser beam at 1064nm. In comparison with the pure hydrogel, the marking properties of the laser-marked PAM/Bi2O3 hydrogel samples vary as the Bi2O3 content increase from 0.17 to 3.0wt% and as the laser power increase from 23.5 to 47.0 W. SEM, XPS, XRD, TGA, Raman spectroscopy, water contact angle and mechanical property tests are performed to characterize the laser-marked PAM/Bi2O3 hydrogels. The results herein indicate that the marking contrast and visual appearance on the surface of the PAM/Bi2O3 hydrogels after laser irradiation are mainly due to the decomposition of Bi2O3 to black bismuth metal.