G20-Germany-Hamburg-2017

ADVOCACY
Pamela Phua, Director, RD&I
Exterior Wall Paints Expertise & Research Group, Global
South East South Asia & Middle East
AkzoNobel Decorative Paints
air, resulting in millions of deaths every year. Rapidly
evolving into a global health crisis, worsening air
pollution in the form of thick smog continually engulfs
Asia’s megacities like Beijing and Delhi as well as
Europe’s metropolises such as Paris and London.
To support urban communities to combat
pollution, AkzoNobel embarked on a programme to
deliver next-generation depolluting paint based on
the technology of photocatalysis of titanium dioxide.
By absorbing sunlight, specifically ultraviolet
radiation, photoactive titanium dioxide particles can
be activated in the presence of oxygen and moisture
to produce free radicals. These highly active radicals
are capable of degrading pollutants like nitrogen
oxide and sulphur oxide, thereby contributing to the
abatement of noxious emissions from motor vehicles
and other human activities. However, the radicals
can also decompose organic constituents in the paint
and consequently impair the paint durability with
excessive chalking. This challenging obstacle was
overcome by a specially formulated inorganic film
having a higher resistance to radical attack.
While cleaning up the air, our photocatalytic paint
can also deliver outstanding self-cleaning properties
with low dirt pick-up to building façades. This
eco-positive benefit derives from both the
degradation of the dirt particles by the radicals and
the photo-induced super-hydrophilicity effect, where
the latter is manifested by a water-loving surface that
allows rain to spread readily on the surface, under
the dirt, suspend it and wash it away.
Water-repellent coating
Alternatively, a façade that stays clean can also be
delivered via super-hydrophobicity. To this end,
AkzoNobel are developing an extremely waterrepellent
coating with inherently low surface energy,
enhanced by multi-scale surface topography. In
essence, water beads form and roll off easily, or →