Experimental Comparison of Wettability by Using Pico- and Microliter Droplets with Range of Liquid Surface Tensions on Porous and Non-porous Substrates

Contact angle measurement is a common method to define wettability and liquid-substrate interactions. Since inkjet printing is based on ejection of separate ink droplets on substrate, contact angle measurement is commonly utilized to characterize inksubstrate interactions in inkjet printing. However, the droplet size in contact angle measurements is typically in microliter scale, whereas picoliter droplets are used in inkjet printing. In this work an experimental comparison between micro- and picoliter droplets to evaluate the influence of droplet volume on contact angle has been made. Wide range of liquid surface tensions on porous inkjet paper and non-porous polymer substrates were tested.