Homogeneous Surface Profiles of Inkjet-Printed Silver Nanoparticle Films by Regulating Their Drying Microenvironment

Obtaining homogeneous surface profiles of inkjet-printed silver nanoparticle films (SNFs) is severely hampered by the classical coffee-ring phenomenon. Traditional approaches to suppress the coffee-ring effect are achieved by improving the uniformity of liquid evaporation rate or introducing inward Marangoni force during ink drying. However, these existing methods involve extra chemicals, treatments, or equipment that will definitely increase the production cost or reduce conductivity. In this study, we demonstrate an inexpensive and efficient method to obtain uniform surface profiles of inkjet-printed SNFs by rationally regulating the drying microenvironment. To this end, a number of surface profiles of printed dots and lines, such as concave, convex, and flat, were first obtained via this method. The underlying principle of this method was then investigated by analytical calculations based on the simplified vapor diffusion model. Consequently, homogeneous surface profiles of inkjet-printed SNFs were achieved on the basis of aforementioned analytical calculations. Our work provides a new possibility to regulate the surface profiles of inkjet-printed nanoparticle-based patterns in the form of low cost and efficiency.