Highly Effective Functionalized Coatings with Antibacterial and Antifouling Properties

Abstract

One of the current challenges in maritime antifouling is the development of new nanostructured coatings which can replace the old protection coatings based on tributyltin biocides prohibited by EU and US legislation as ecologically dangerous. In our study, antibacterial/ antifouling polymer coatings containing innovative dual functionalized nanocapsules demonstrate high antifouling activity in various tests. Capsules are MCM-48 SiO 2 nanoparticles loaded with eco-friendly 4,5dichloro-2-octyl-4-isothiazolin-3-one (DCOIT) antifouling agent and decorated with dimethyloctadecyl [3-(trimethoxysilyl) propyl] ammonium chloride or dimethyltetradecyl [3-(triethoxysilyl) propyl] ammonium chloride (quaternary ammonium salts, QASs) also possessing antifouling activity. Cross section images of the coatings demonstrated the absence of the capsule aggregates in the coatings with slight increase of the surface roughness. The formulated coatings revealed excellent antibacterial performance against E. coli and Staphylococcus aureus according to ISO 22196:2011 protocol. This antifouling activity was also confirmed by immersion of the coated polyvinyl chloride (PVC) panels at a depth of 8−9 m in the sea (Eilat, Israel). Biofouling coverage of 6.9% was observed for nanocapsulesloaded coatings (5 wt % concentration of nanocapsules) compared to the 49% of the coverage for nonmodified coating after 6 months of immersion. The nanocapsules-loaded coatings with dual antifouling functionality demonstrated antifouling activity even after complete release of encapsulated DCOIT because of chemically attached QAS groups on the nanoparticles surface. Moreover, active antifouling materials presented in nanocapsules do not demonstrate any toxicity to the brine shrimps Artemia salina, which are widely used in the food industry.

Use of Nanotechnology to Mitigate Biofouling in Stainless Steel Devices Used in Food Processing, Healthcare, and Marine Environments

“…Several materials with good biocidal and antifouling activity have been reported [14,15,[124][125][126][127][128][129][130]. Among these, the following stand out: halloysite clay nanotubes, mesoporous silica nanocapsules, and layered double hydroxides.…”

“…The functionalization of surfaces, especially silica nanocapsules with some quaternary ammonium salts, conferred the possibility of having passive protection due to covalent bonding to the nanoparticle surface [124]. Quaternary ammonium salts are positively charged cationic compounds; bacterial cell membranes are negatively charged.…”

“…It is well known that quaternary ammonium salts are toxic and put non-target species at risk. To solve this, more friendly replacements have been sought [124,147], with good, but not yet friendly enough, results.…”

Preparation and evaluation of organosilica nanocapsules encapsulating DCOIT by using the response surface optimization

“…Compared with the EE (%) of organosilica nanocapsules containing DCOIT prepared by other methods, such as 3.8% by solvent evaporation method, 38 10% by Pickering emulsion polymerization method, 39 and 31.5% by drug impregnation method, 40 the EE (%) was as high as 49.15% by autocatalytic sol–gel method in this work, which also indicates that the prepared organosilica nanocapsules will have great application potential in encapsulating other kinds of oily core materials.…”

Antifouling Performance of Carbon-Based Coatings for Marine Applications: A Systematic Review

“…These strategies can prevent, and delay biofilm formation or control already developed biofilms [ 24 , 30 , 31 ]. While preventive measures comprise both antimicrobial and AF surfaces, control procedures can involve the use of bacteriophages, QS inhibitors, the disruption of the biofilm matrix, as well as the use of matrices with self-cleaning properties [ 32 , 33 , 34 , 35 , 36 ].…”