Surface evolution in viscoelastic medium : Relaxation and ripening

Roughening process in polydimethyl siloxane (PDMS) using atomic force microscopy is being studied using scaling law. As solidified PDMS showed surface undulation that is attributed to Grinfeld type instability. When the surface is annealed at 125 °C, a negative growth exponent is obtained. The growth exponent for annealing at 175 °C case was also found to be consistent with the diffusion driven model. However, the surface treated at this temperature does not exhibit any correlation length. For this particular type of solidification process, rougher surfaces led to larger growth exponent.