Inkjet Printing Enabled Controllable Paper Superhydrophobization and Its Applications.

Area of Science:

• Materials Science
• Surface Chemistry
• Microfluidics

Background:

• Paper's porous structure and hydrophilicity complicate selective surface modification.
• Capillary effects cause unwanted diffusion of functionalizing agents.

Purpose of the Study:

• To develop a precise method for partial functionalization of paper substrates.
• To create Janus superwetting and patterned superwettable papers using inkjet printing.

Main Methods:

• Computer-controlled inkjet printing for precise deposition of hydrophobic and hydrophilic coatings.
• Control of ink quantity to achieve differential surface wettability.
• Fabrication of paper-based microfluidic devices and analytical sensors.

Main Results:

• Achieved precise hydrophobic functionalization on one side of paper, creating Janus superwetting materials.
• Demonstrated superhydrophobic surfaces with static water contact angles up to 154°.
• Fabricated paper-based microfluidics with a resolution of approximately 600 μm and a Ni(II) colorimetric sensor.

Conclusions:

• Inkjet printing offers a simple and innovative approach for fabricating Janus materials and complex patterns on paper.
• This method overcomes challenges associated with partial functionalization of porous materials.
• The developed technique paves the way for practical applications in paper-based devices.