Development of superhydrophobic coating on paperboard surface using the Liquid Flame Spray

• Published in: Surface & coatings technology Vol. 205; no. 2; pp. 436 - 445
• Main Authors: Teisala, H., Tuominen, M., Aromaa, M., Mäkelä, J.M., Stepien, M., Saarinen, J.J., Toivakka, M., Kuusipalo, J.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-10-2010; Elsevier
• Subjects: Applied sciences; Coating; Contact angle; Cross-disciplinary physics: materials science; rheology; Droplets; Exact sciences and technology; Liquid Flame Spray; Materials science; Metals. Metallurgy; Nanocomposites; Nanomaterials; Nanostructure; On-line process; Paperboard coating; Physics; Production techniques; Scanning electron microscopy; Sprayers; Sprays; Superhydrophobic; Surface treatment; Surface treatments; Titanium dioxide nanoparticle; Paperboard coating; Superhydrophobic; On-line process; Titanium dioxide nanoparticle; Liquid Flame Spray; Nanoparticles; Ontogenesis; Surface treatments; Coatings; Flame spraying
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2010.07.003

This paper introduces a new method for generating nanoscale coatings in a continuous roll-to-roll process at normal pressure. Nanostructured and transparent coating, based on titanium dioxide nanoparticles, was successfully deposited on-line at atmospheric conditions on pigment coated paperboard using a thermal spray method called the Liquid Flame Spray (LFS). The LFS coating process is described and the influences of process parameters on coating quality are discussed. Nanocoating was investigated by a field emission gun scanning electron microscope (FEG-SEM), an atomic force microscope (AFM), an X-ray photoelectron spectroscopy (XPS) and a water contact angle measurement.
The highest measured water contact angles on the nanocoated paperboard surface were over 160°. Falling water droplets were able to bounce off the surface, which is illustrated by high speed video system images. Regardless of the high hydrophobicity, the coating showed sticky nature, creating a high adhesion to water droplets immediately as the motion of the droplets stopped. Nanocoating with full coverage of the substrate was produced at line speeds up to 150
m/min. Therefore, the LFS coating has scale up potential to industrial level as an affordable and efficient method for coating large volumes at high line speeds.