Controllable depositing behaviors and deposited morphologies of inkjet droplets on high energy surface

Abstract

The high energy surface (HES) could realize a super-spreading process for droplet. In this work, a facile method was applied to fabricate HES by hydrothermally treating aluminum foil. The inkjet ink is obtained by dissolving poly acrylic acid (PAA) in ethanol. The depositing behaviors of inkjet droplet was investigated and controlled with pinned three phase contact lines. And the influence of coffee ring effect on the depositing behavior of inkjet droplet could be regulated to generate a variety of deposited morphologies, including super-spreading structure, ring structure, and homogeneous structure. With the inkjet printed pattern of PAA solution ink on the HES, a patterned wettability surface with high energy area and low energy area could be fabricated by modifying the surface with fluoro-alkyl silanes and removing the inkjet printed PAA with deionized water, which could transport water from bottom to up with a high wettability contrast. This work presented a systematic study in controllable depositing behaviors and deposited morphologies of the inkjet droplets on high energy surface. It has a great potential for the development of material patterning, 3D printing as well as related interface researching.