Article published on mars 2008Polymer grafting
Functionality tailored to requirements and with added value
Graftfast© is the first process in the world developed to graft a vast range of polymers on a huge variety of materials, regardless of whether or not they are conductive, in one single step. The patented, process will be developed by a new start-up, Pegas-Tech.
Paint for protecting bodywork,
self-cleaning, anti-UV coatings
for lenses or functional films
(hydrophobic, antibacterian,
etc.) for textiles, nanometric coatings
for microelectronics, photovoltaic solar
energy systems, healthcare and aerospace
applications, etc.
Polymer surface coatings have become
indispensable throughout industry.
For example, the polymer metallizing market
is growing at a rate of over 7 % a year, the
textile coatings market at 2 to 5 % a year and
coatings for applications in the healthcare
industry at a rate of over 12 %.
"Polymer grafting is one of the key surface
chemistry technologies used to protect
materials or modify their properties,"
explained Sébastien
Roussel, one of the
team that invented
the Graftfast©
processin 2006,
and who is currently
heading the project to
set up Pegas-Tech, in
incubation at CEA.
Up until now, grafting thin polymer
films (less than one micron thick) was
carried out by plasma deposition, irradation
or by an electrochemical
treatment involving the application of
an electric potential to the material
surface (electrografting).
Graftfast© is the first purely chemical
deposition process performed using an
aqueous carrier : it uses activators and no
electric current is required. This means
that it is suitable for any type of material,
whether or not it conducts electricity or is
an insulant, including glass, metal, Teflon®,
plastic, ceramics and carbon nanotubes,
etc. The process, which is much simpler
and more environment-friendly than any
surface treatment process developed to
date, is also less expensive. Graftfast© is
protected by 12 patent applications.
"We characterised deposited polymer
films in great detail," Sébastien Roussel
explained. "We have now pefected grafting
for the majority of vinyl polymers, from a few
à to 800 nm on surfaces ranging from one
nm2 to one m2. We can control the thickness
of the coating with great precision. The
coating adheres incredibly well thanks to
covalent bonds between the film and the
substrate and does not damage the
topography of even the most complex
type of substrate." It may also be used
as an adhesion primer, especially in the
case of nanoparticle integration and
functionalized surface treatments,
etc.
Depending on the area of application,
the process can be deployed via two
start-ups, Pegas-Tech and Alchimer, or
by being granted a licence by CEA.
