Experimental study on H2O/PEGDA/Irgacure hydrogel droplet evaporation and polymerization

This work is devoted to experimental investigation of H2O/PEGDA/Irgacure hydrogel sessile droplet evaporation and polymerization caused by UV radiation. With the help of thermal imaging measurements, an increase in the temperature of the droplet surface during polymerization by 0.9–1.2 °C was established. Three types of evaporation/polymerization modes for hydrogel droplet were observed. At the first mode (0 < t < 14 min) hydrogel droplet evaporates and polymerizes at constant contact radius. The second mode (14 < t < 34 min) characterized by contact line instability growth. At the end of the third mode (t > 34 min), the geometric parameters of the hydrogel droplet stop changing.