Temperature-Regulated Wettability of Conductive Films Based on Electrophoretic Silver Nanoparticle Concentrates

Uniform rough films containing up to 73 at % silver have been obtained by the Doctor Blade method from concentrated silver nanoparticle organosols stabilized with sodium bis(2-ethylhexyl) sulfosuccinate. Variations in the wettability of the films have been studied in detail as depending on the conditions of their heat treatment within a temperature range of 50–500°C. The temperature dependence of the contact angles is not monotonic and implies the transition from superhydrophilic to weakly hydrophilic systems due to the processes of sintering of nanoparticles and thermal decomposition of the stabilizer. It has been experimentally shown that a transition from nonconductive to conductive coatings (from 500 to 105 mΩ/sq) is accompanied by a drastic increase in the contact angle (from 25 to 78°).