Covalent Grafting of Chitosan onto Stainless Steel through Aryldiazonium Self-Adhesive Layers

Abstract

Although the conventional methods for strong attachment of chitosan onto stainless steel require many steps in different solvents, it has been demonstrated in this work that covalent grafting of chitosan on a steel surface can be easily achieved through the formation of a self-adhesive surface based on aryldiazonium seed layers. Initially, a polyaminophenyl layer is grafted on a stainless steel surface by means of the one-step GraftFast(TM) process (diazonium induced anchoring process). The grafted aminophenyl groups are then converted to an aryldiazonium seed layer by simply dipping the substrate in a sodium nitrite acidic solution. That diazonium-rich grafted layer can be used as a self-adhesive surface for subsequent spontaneous coating of chitosan onto the steel surface. X-ray photoelectron and impedance electrochemical spectroscopies were used to characterize the pristine and modified steel samples. As evidenced from impedance and linear polarization results, the primary polyaminophenyl layer characterized by a high charge transfer resistance contributed to better protection against corrosion of the resulting chitosan-coated steel in sulfuric acid medium.

On the chemical grafting of titanium nitride by diazonium chemistry

“…In the case of iron powder, the C 1s spectrum behaves as a thick aminophenylene film as already observed for the stainless steel surface in a previous work. 39 In line with the C 1s core level spectrum, the appearance of a new N1s peak at 400.4 eV representing the diazo bridges as well as the significant increase in the intensity of the amine peak at 399.4 eV ( Figure 6) allows us to confirm the grafting of the aminophenyl functionalities on the surface of titanium nitride substrates in the presence of both homogeneous and heterogeneous reducing agents. Similar to the spontaneous grafting, the aminophenylene grafted in the presence of reducing agents does not incorporate any amount of diazonium ion which is characterized by the N 1s peaks at 403.8 and 405.1 eV.…”

“…Aside from TiN and CMV membrane in this work, a thick aminophenylene film (9.8 ± 1.5 nm) has been reported to graft onto stainless steel surface. 39 Our obtained results clearly…”

“…The thickness of the aminophenylene grafted layers could be estimated by the standard overlayer model from the attenuation of the Ti 2p peak intensities before and after modification: 39,40 ‫ܫ/ܫ‬ = exp(− ‫)ߠ݊݅ݏߣ/݀‬ (i) where d is the layer thickness, λ the photoelectron escape depth, θ the takeoff angle, and I/I 0 the ratio of the Ti 2p peak intensities of the bare and grafted surfaces (Figure 4). In our experiment, the takeoff angle was 90°.…”

Fabrication of nonfouling, bactericidal, and bacteria corpse release multifunctional surface through surface-initiated RAFT polymerization

“…The thickness of self-assembly monolayer or physically adsorbed film is impossible to achieve such a thick thickness. [40][41][42] So, the "grafting from" method through RAFT polymerization is suitable to construct copolymer brush coating to modify biomaterials. Apart from hydrophilicity, topography 43,44 change is another important factor affecting the anti-adhesion properties of the material surface.…”

N‐halamine coatings formed via the electroreduction of in situ generated diazonium cations: toward antimicrobial surfaces

“…These films could have various applications; for some of them, it is better to have monolayer notably amine‐terminated monolayer, which could be obtained using protected p ‐aminobenzene diazonium salt or compact thick layer (anticorrosion coating) or porous thick layer depending also on the post‐functionalization treatment . Notably, if the layer contains primary amino groups, which can undergo a diazotization in order to graft it on chemical compounds or solid compounds such as chitosan or silicon nanoparticules …”