Cleaning, impregnation, lacquers and paints
Many cleaning and impregnating agents are advertised with the term "nano". The Woodrow Wilson database currently (2017) lists about 150 products in the category "cleaning" and about 200 products in the category "automotive”. In fact, not all of these products labeled "Nano" contain nanomaterials or have been manufactured using nanotechnologies (LGL 2012). Nanotechnologies in surface treatment products can create self-cleaning, antimicrobial or photocatalytic effects, increase scratch resistance or create UV protection. The use of nanotechnologies in lacquers and paints has very similar objectives. For this purpose, conductive or heat-insulating lacquers and coatings are under development (VdL 2010).
The following materials are mainly used in varnishes and paints in nanoscale form (VdL 2010):
- Nanoscale titanium dioxide is used because of its photocatalytic properties. In wood glazes it serves as a UV absorber.
- Silica: Pyrogenic silicic acid (amorphous silica) has been used for a long time in varnishes in order to improve their flowability. The particles have particle sizes between 4 and 20 nm.
- (Industrial) carbon black: serves as a color pigment in varnishes and paints.
- Nanoscale zinc or cerium oxide is UV-absorbing and has an antimicrobial effect.
- Nanocomposite polymer dispersions in stain-resisting facades
- Nano silver is used in lacquers and paints as an antimicrobial additive.
Apart from nano silver, all the above-mentioned materials are generally supplied as bagged cargo and used as powders or aqueous formulations.
Surface treatment (such as impregnation, sealing spray) and cleaning products contain additives such as nanoscale silver, fluorocarbon resins and silicon groups (LGL 2012) as well as (aluminum) oxide as scratch protection.
- LGL (Bayerisches Landesamt für Gesundheit und Lebensmittelsicherheit), 2012: Nanomaterialien in Lebensmitteln und Verbraucherprodukten
- VdL (Verband der deutschen Lack- und Druckfarbenindustrie) 2010: VdL-Leitfaden für den Umgang mit Nanoobjekten am Arbeitsplatz