Effect of temperature on the dynamics and geometry of reactive-wetting interfaces around room temperature.

The temperature effect on the dynamics and geometry of a mercury droplet (∼150 μm) spreading on a silver substrate (4000 Å) was studied. The system temperature was controlled by a heating stage in the temperature range of -15 °C < T < 25 °C, and the spreading process was monitored using an optical microscope. We studied the wetting dynamics (droplet radius and velocity) as a function of temperature. We found that for all studied temperatures, the spreading radius R(t) grows linearly with time, with a velocity value depending on temperature. We also studied the temperature effect on the kinetic roughening properties of the advancing interface (growth (β) and roughness (α) exponents). Our results show that the growth exponent increases with temperature while the roughness exponent is relatively constant. In addition, we obtained the system's activation energy at this temperature range.