Bioinspired Aryldiazonium Carbohydrate Coatings: Reduced Adhesion of Foulants at Polymer and Stainless Steel Surfaces in a Marine Environment

Abstract

Surface treatments that minimise biofouling in marine environments are of interest for a variety of applications, such as environmental monitoring and aquaculture. We report on the effect of saccharide coatings on biomass accumulation at the surface of three materials that find applications in marine settings: stainless steel 316 (SS316), nylon-6 (N-6), and poly(ether sulfone) (PES). Saccharides were immobilized via aryldiazonium chemistry; SS316 and N-6 samples were subjected to oxidative surface pre-treatments prior to saccharide immobilization, whereas PES was modified via direct reaction of pristine surfaces with the aryldiazonium cations. Functionalization was confirmed by a combination of X-ray photoelectron spectroscopy, contact angle experiments and fluorescence imaging of lectinsaccharide binding. Saccharide immobilization was found to increase surface hydrophilicity of all materials tested, while laboratory tests demonstrate that the saccharide coating results in reduced protein adsorption in the absence of specific protein-saccharide interactions. The performance of all three materials after modification with aryldiazonium saccharide films was tested in the field via immersion of modified coupons in coastal waters over a 20 day time period. Results from combined infrared spectroscopy, light microscopy, scanning electron and He-ion microscopy and adenosine-triphosphate content assays show that the density of retained biomass at surfaces is significantly lower on carbohydrate modified samples with respect to unmodified controls. Therefore, functionalization and field test results suggest that carbohydrate aryldiazonium layers could find applications as fouling resistant coatings in marine environments.

Bioinspired electro-permeable glycans on carbon: Fouling control for sensing in complex matrices

“…Work from our group has shown that aryldiazonium cations prepared from saccharidebearing aminophenol precursors as in Figure 1 [13], can be used to spontaneously form adlayers of mono-and di-saccharides from solution in a single step. This reaction yields covalent immobilization of glycans on a range of materials including carbon [13][14][15], polymers [16,17], metals and alloys [13,18]; furthermore, it has been extended to more complex glycans that display specific binding interactions with organic substrates, such as cyclodextrins [19].…”

Heterogeneous-phase Sonogashira cross-coupling reaction on COC surface for the grafting of biomolecules – Application to isatin

“…Recently, we have successfully functionalized COC surfaces in absence of any plasma activation by reducing grafting of aryldiazonium salts via transient formation of the corresponding aryl radicals [16]. Widely used to modify metallic surfaces for their electro-or chemical grafting ability [17][18][19][20], these species also proved to be competent for the functionalization of polymeric surface [21]. From their reduced form, radicals covalently bind to the surface allowing various chemical functions (acids, nitro or bromo groups) to be introduced on the COC surface [16].…”

Microcapsules-based multifunctional coatings for anticorrosion and antibacterial applications

“…The ban of TBT-SPC paints has raised the importance of examining and omitting the environment toxicity of different antifouling coatings before using it in real industrial applications. Different types of antifouling coatings were developed, such as foul release coating [3] , zwitterionic polymers [14][15][16], enzyme [7,17,18] and bioinspired superhydrophobic surfaces [19][20][21][22] that possess low surface energy and hierarchical structure. Additionally, natural compounds such as the essential oils were found to have significant antimicrobial function [23].…”

“…Subsequently, the performance of carbohydrates immobilized fouling resistant coatings in the marine environment were studied on three different substrates: stainless steel, nylon and PES. According to the field test results in a coastal environment for 20 days, the carbohydrate coatings show good promise as an environmentally friendly solution for reducing adhesion and retention of marine foulants [22].…”

“…Subsequently, the antifouling performance was evaluated based on the coverage percentage of different macroorganisms such as the algae, barnacles, bryozoans, ascidians and tubeworms [88]. The effect of aryldiazonium saccharide coatings on biomass accumulation on the surfaces of different materials was investigated by immersing in coastal waters over a 20 days period [22]. The performance of the coating was subsequently justified through different techniques including infrared spectroscopy, light microscopy, scanning electron and He-ion microscopy.…”