Imbibition and Evaporation of Water Droplets on Paper and Solid Substrates

Abstract

Imbibition and evaporation of picoliter (pL) sized water droplets on paper media commonly used for inkjet printing is measured using high speed imaging system. Three types of uncoated and coated paper samples were chosen: multipurpose uncoated paper ͑80 g/m 2 ͒, matte coated paper ͑230 g / m 2 ͒, and gloss coated paper ͑240 g / m 2 ͒. As a reference, the rate of the evaporation process was quantified by using three impermeable solid substrates with different wetting characteristics, i.e., silicon, glass, and hydrophobized glass. It is shown that for water droplets of about 60 pL, imbibition is the dominant phenomenon on the matte and gloss coated paper leading to a total drying time (imbibition plus evaporation) of 10-15 ms for gloss coated paper and 30-150 ms on the matte coated paper. In the latter sample, different regimes in the imbibition process were correlated with the layered structure of the sample. The drying process on the multipurpose paper is dominated by evaporation, with initial drying rate of 0.4-0.6 pL/ms.

Source-like Solution for Radial Imbibition into a Homogeneous Semi-infinite Porous Medium

“…The measured slope might be slightly smaller than 1/3 because gravity is not totally negligible for the larger measured radii. Figure 4 also compares the full solution of the imbibition problem, equation (8), with its approximation for long times, equation (9). Results of the comparison show that the relative error between the full solution and its approximation for long times becomes less than 10% for T > 120, which in our experiment corresponds to t > 0.4 s.…”

Droplet evaporation on porous fabric materials

“…6 a, where is the initial mass of liquid and is the final evaporation time. As a result, the evaporation rates are the largest (16.4 g/s) for the fabric substrate compared with the other substrates (7.8 g/s for the paper and 6.4 g/s the flat PDMS) 30 . For most of the evaporation process ( s), linearly decrease with t , indicating that the evaporation rate dm / dt is proportional to regardless of the substrates.…”

“…1 b, and enhancement of the wetted surface area, represented in Fig. 1 c 29 , 30 . Regarding droplet evaporation on porous substrates, how spreading and imbibition promote evaporation is a central question.…”

Imbibition of Femtoliter-Scale DNA-Rich Aqueous Droplets into Porous Nylon Substrates by Molecular Printing

“…The phenomenon of droplet imbibition into porous substrates is a widely investigated topic, because of its great importance for many natural systems, such as absorption of water by seeds and dry wood or by hydrophilic colloids, as well as in different relevant technological applications, for example, droplets inkjet printing into paper, printed electronics, drug screening, fabrication of biosensors, 1,2 or colloidal assembly into porous substrates. 3,4 Whereas on nonporous substrates, the interplay of capillary motion and solvent evaporation determines the final deposition of the drop, a more complex scenario emerges for a droplet impacting onto a porous substrate, due to the droplet imbibition into the pores.…”

“…The phenomenon of droplet imbibition into porous substrates is a widely investigated topic, because of its great importance for many natural systems, such as absorption of water by seeds and dry wood or by hydrophilic colloids, as well as in different relevant technological applications, for example, droplets inkjet printing into paper, printed electronics, drug screening, fabrication of biosensors, , or colloidal assembly into porous substrates. , …”