Highly dispersed screen-printable nanocomposite paste for self-cleaning curtain walls

Traditional technologies to fabricate self-cleaning coatings on curtain walls usually involve high initial equipment investment and complex fabrication process, which leads to high production cost, e.g.10-20 USD per square meter.

In the present work, researchers have developed a novel highly dispersed nanocomposite paste which is suitable for the low-cost facile screen-printing process to fabricate highly transparent multifunctional coatings on glass. The developed coating has extremely high dispersion of the internal semiconductor nanoparticles (average particle size=5nm), so that it could inhibit the Rayleigh scattering effect and hence has high transparency (over 98% in visible region).

Meanwhile, the surface of the coating via sunlightactivated has the property of photocatalysis and super-hydrophilicity (contact angle less than 1°), which can not only decompose the organic compounds on surface, but also brush away the inorganic dust easily by rainwater. Moreover, the coating after tempering process is robust (hardness=8H;life time greater than 20 years) and it can prevent the glass from the corrosion of sandstorm and acid rain. The paste itself is waterbased with lower volatile organic compound (VOC<3g/L) and zero heavy metals, which is environmental friendly for human beings. The fabrication process of the paste is cheap and facile, easy for transportation and storage. The estimated cost of the developed selfcleaning coating will be no more than 1.5 USD per square meter.

Special features and advantages

• Cheap fabrication cost: no more than 1.5 USD per square meter.
• Environmental friendly: water-based with lower volatile organic
• compound (VOC less than 3g/L) and zero heavy metals,
• Superior hydrophilic property: contact angle less than 1°
• High dispersion of nanoparticles: average particle size 5nm
• High transparency : over 98% in visible region
• Robust : hardness=8H; life time greater than 20 years after the tempered
• process

Applications

• Photovoltaic power station
• Curtain walls
• Windows
• Metal surface such as the washing machine cylinder which is
• based on stainless steel
• Rearview mirror