30 research outputs found
Surface Engineering of Bromine-Based Plasma Polymer Films: A Step toward High Thiol Density Containing Organic Coatings
Nowadays,
the development of synthetic methods regarding the fabrication
of −SH containing organic coatings continues to attract a considerable
attention. Among the potential techniques, the plasma polymerization
appears as one of the most promising method but the difficulty to
control the chemical composition of the layers is highly limiting.
In this context, in this work, we report on an original method combining
dry and wet chemistry approaches in view of selectively incorporating
−SH functions in organic coatings. Our strategy is based on
the (i) synthesis of a bromine-containing plasma polymer film, followed
by (ii) a selective grafting of dithiol-based molecule on C–Br
bond. Investigating the plasma polymerization process has revealed
that, in our experimental window, the load of energy in the discharge
has little influence on the chemical composition as well as on the
cross-linking degree of the layers. This behavior is explained by
considering the concomitant influence of the gas-phase reactions and
the supply of energy to the growing film through ion bombardment.
With regard to the functionalization strategy, based on comparative
X-ray photoelectron spectroscopy measurements, it has been unambiguously
demonstrated that a selective reaction between propanedithiol and
the C–Br bond acting as the reactive center takes place resulting
in the removing of the bromine atom and the incorporation of −SH
groups in the PPF. Depending on the grafting reaction duration, the
relative proportion of carbon bearing the −SH group is found
to evolve from 4 to 6%. On the other hand, the dissolution of unbounded
bromine-based species in the liquid medium during the grafting procedure
is also evidenced. The whole set of our results clearly demonstrates
the attractiveness of our strategy paving the way for new development
in the fabrication of −SH-rich-containing organic thin films