Surface Engineering of Bromine-Based Plasma Polymer Films: A Step toward High Thiol Density Containing Organic Coatings

Abstract

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.

Development of Diketopyrrolopyrrole-Based Smart Inks by Substituting Ionic Pendants and Engineering Molecular Packing Structures

“…For Br, typical binding energy is observed at 70.3 and 67.6 eV . The peak position at 169.6 and 170.8 eV is consistent with sulfur bonded to carbon (C–S bond) in bistriflimide moieties . It is further confirmed that the peak at 690.2 eV is consistent with fluorine bonded to carbon (C–F bond) .…”

The wrinkling concept applied to plasma‐deposited polymer‐like thin films: A promising method for the fabrication of flexible electrodes

“…It has been reported that for PPF material, the cross‐linking degree is inversely correlated with the total secondary ions intensity for spectra recorded in the positive mode. [ 30,31 ] Within our experimental window, it can be concluded that the cross‐linking density increases with T s (Figure S1), which suggests an increase in the stiffness of the layer. This trend has been already reported and is explained through a decrease in the energy density brought by positive ions to the growing film with respect to the total amount of matter deposited.…”

Increasing Bromine in Intracellular Organic Matter of Freshwater Algae Growing in Bromide-Elevated Environments and Its Impacts on Characteristics of DBP Precursors

“…When conducting the high-resolution scan for bromine (insert Figure S4), the primary signal was found at 72.9 ± 0.15 eV, indicating dominance of covalent C−Br bonding of organic bromine, not Br 2 or ionic bromide that generally occur at 69−67 eV. 39 Note that algal cells were washed to remove any bromide residue from the cultures before SEM-EDS analysis, so it is likely that only bromine with strong covalent bonds remained on the algal surface. The predominance of a covalent C−Br bond in MA and CH cell surfaces is likely similar to that found in the Laminaria cell wall (i.e., C−Br revealed by X-ray absorption), 22 implying that strongly bonded bromine with biomolecules does occur in freshwater Chlorella and Microcystis.…”

“…XPS scanning also confirmed chlorine signals, indicating that both algae can accumulate multiple halogens when present in their environments. When conducting the high-resolution scan for bromine (insert Figure S4), the primary signal was found at 72.9 ± 0.15 eV, indicating dominance of covalent C–Br bonding of organic bromine, not Br 2 or ionic bromide that generally occur at 69–67 eV . Note that algal cells were washed to remove any bromide residue from the cultures before SEM-EDS analysis, so it is likely that only bromine with strong covalent bonds remained on the algal surface.…”