Preparation of Microcapsules Coating and the Study of Their Bionic Anti-Fouling Performance.

Yu Li,Peiqing Wang,Zehui Guo,Guoqing Wang,Aimin Wang

doi:10.3390/ma13071669

Abstract

With the increasing demands to better the marine environment, environmentally friendly anti-fouling coatings have attracted attention from society. Adding hydrolyzable microcapsules without toxin to paints is a very useful and safe method to get bionic anti-fouling coatings with a micro-nano surface structure. Based on this trend, a form of environment-friendly microcapsules were prepared through mini-emulsion polymerization. The target microcapsules had a poly(urea-formaldehyde) (PUF) shell and a mixed core of silicone oil and capsaicin. Additionally, the microcapsules were introduced into zinc acrylate resin to obtain bionic anti-fouling coatings with micro-nano morphology. The effects of polyvinyl alcohol (PVA) molecular weight, stirring rate, and temperature on the morphology of the microcapsules were studied by optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that spherical nanoparticles with smooth surfaces were obtained, and the mean diameter was approximately 1.38 μm when the molecular weight of PVA was 77 K, the stirring rate was 600 rpm and the temperature was 55 °C. Fourier-transform infrared spectra (FTIR) results showed that the silicone oil and capsaicin were successfully encapsulated, the core materials of the microcapsules reached 72.37% and the yield of microcapsules was 68.91% by the Soxhlet method. Furthermore, the hydrophobicity, corrosion resistance and anti-fouling performance of the coatings were evaluated by the water contact angle, electrochemical and real-sea tests. The results indicated that the anti-fouling coatings had excellent hydrophobicity and anti-fouling performance due to the micro-nano convex structure and the release of core materials. Encouragingly, the anti-fouling coatings show excellent and long-term anti-fouling performance, which is expected to be widely applied in marine anti-fouling coatings.

Highlights

Anti-fouling coatings usually rely on the release of toxins to achieve the effect of anti-fouling [1,2,3,4,5,6].Conventional anti-fouling agents typically include toxic fungicides and heavy metals, which can cause different effects on the environment [7,8,9,10]
The emulsifier overcomes the cohesive energy of the oil phase and the surface energy for droplet formation, and the small oil droplets are sufficiently dispersed in the aqueous phase to form a stable emulsion under mechanical stirring
The monomers urea and formaldehyde are added to the aqueous phase and undergo a condensation reaction to form a linear pre-polymer on the surfaces of the oil Materials 2020, 13, x FOR PEER REVIEW

Summary

Introduction

Anti-fouling coatings usually rely on the release of toxins to achieve the effect of anti-fouling [1,2,3,4,5,6].Conventional anti-fouling agents typically include toxic fungicides and heavy metals, which can cause different effects on the environment [7,8,9,10]. Anti-fouling coatings usually rely on the release of toxins to achieve the effect of anti-fouling [1,2,3,4,5,6]. It is necessary to discover an environmentally-friendly anti-fouling agent for use in anti-fouling paints, especially suitable for anti-corrosion in fish farming and offshore wind power. Micro-nano anti-fouling coatings are currently a good direction for researchers exploring bionic anti-fouling paints [15,16,17,18]. This type of coating has a micro-nano structure that is generated at Materials 2020, 13, 1669; doi:10.3390/ma13071669 www.mdpi.com/journal/materials

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