Novel Structured Surface Coatings for Protection from Chemical, Biological and Radiological Agents

Chemical warfare has existed since antiquity, however it became recognisable in its current form during World
War 1 with the use of chlorine gas as a weapon. With the advent of modern chemistry, the range of substances
that could be used as chemical warfare agents has significantly increased. Many of these chemical agents are
persistent in the environment and on surfaces as such equipment in contact with chemical weapons (CWs)
must be decontaminated. Decontamination and destruction of contaminated surfaces often involves large
quantities of caustic liquid reagents such as concentrated sodium hypochlorite1
to hydrolyse the chemicals for
safe disposal. Surfaces that can actively decontaminate themselves are of great interest as they could help to
control or minimise surface contamination and its spreading.
Surface chemistry and structure is well known to affect the behaviour of liquids on the surface with famous
examples such as the lotus effect using a hierarchical structure to produce a fluoropolymer free
superhydrophobic surface2
Hierarchy has been showed to significantly increase the hydrophobicity of a
surface by trapping pockets of air underneath the droplet. Hierarchal surfaces have been created in several
ways including lithographically3
or via the combination of different sizes of nano and micro particles, these
surfaces are very rough having a large surface to projected surface area ratio.
Functional surfaces is an area of intense interest with applications in antifouling, dynamic optical properties,
adhesion. The addition of specific reactive chemical functionality on a surface can add additional functionality
to surfaces with controlled structure. For example, covalently tethered functional groups have been shown to
produce surface with a range of properties including biocidal4
. It is thought that the combination of the high
surface area and contact angles of hierarchal surfaces and functional moieties that can neutralise chemical
weapons would produce a surface that is easy to clean and capable of active decontamination.