scholarly journals Composite Slow-Release Fouling Release Coating Inspired by Synergistic Anti-Fouling Effect of Scaly Fish

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2602
Author(s):  
Yanqiang Mo ◽  
Peihong Xue ◽  
Qiang Yang ◽  
Hao Liu ◽  
Xu Zhao ◽  
...  

Inspired by the antifouling properties of scaly fish, the conventional silicone coating with phenylmethylsilicone oil (PSO/PDMS) composite coating was fabricated and modified with single layer polystyrene (PS) microsphere (PSO/PDMS-PS) arrays. The fish scale like micro-nano structures were fabricated on the surface of bio-inspired coating, which can reduce the contact area with the secreted protein membrane of fouling organisms effectively and prevent further adhesion between fouling organisms and bio-inspired coating. Meanwhile, PSO exuded to the coating surface has the similar function with mucus secreted by fish epidermis, which make the coating surface slithery and will be polished with the fouling organisms in turbulent waters. Compared to PSO/PDMS coating without any structure and conventional silicone coating, PSO/PDMS-PS showed better antiadhesion activity against both marine bacteria and benthic diatom (Navicula sp.). Additionally, the existence of PS microspheres can reduce the release rate of PSO greatly, which will extend the service life of coating. Compared to PSO/PDMS coating, the sustained release efficiency of PSO/PDMS-PS coating can reach 23.2%. This facile method for fabricating the bio-inspired composite slow-release antifouling coating shows a widely fabricating path for the development of synergistic anti-fouling coating.

2014 ◽  
Vol 1061-1062 ◽  
pp. 155-161 ◽  
Author(s):  
Yuan Sun ◽  
Shuang Liang ◽  
Zhi Zhou Zhang

In this study, a polydimethylsiloxane (PDMS) coating filled with low concentrations of selected carboxyl modified multi-walled carbon nanotubes (cMWCNTs) has been fabricated. The antifouling properties of cMWCNTs-filled PDMS coatings were tested and the diversity level and succession phenomenon of marine fouling microbial communities were analyzed using single strand conformation polymorphism (SSCP) method. Marine adhesion test showed that cMWCNTs-filled PDMS coating presented decent antifouling property. SSCP analysis revealed that fouling prokaryotic species on the cMWCNTs-filled PDMS coating presented high and stable diversity level while diversity and dominance level of fouling eukaryotic species were relatively low, similar to those on PDMS alone and other four antifouling coating surface without nanoparticles, suggesting that the main mechanism by which cMWCNTs-mediated surface nanostructure improves antifouling capacity may have no direct relationship with the patterns in the context of succession dynamics of prokaryotic and eukaryotic microbial communities.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Leila Javazmi ◽  
Anthony Young ◽  
Gavin J. Ash ◽  
Tobias Low

AbstractFertilisers are essential in modern agriculture to enhance plant growth, crop production and product quality. Recent research has focused on the development of delivery systems designed to prolong fertiliser release. This study introduces a new technology to encapsulate and release molecules of fertilisers by using multi-layered electrospun nanofibre as a carrier. Single-layer poly L-lactic acid (PLLA) nanofibres loaded with urea were fabricated using electrospinning. Triple-layer nanofibrous structures were produced by electrospinning polyhydroxybutyrate (PHB) nanofibres as external layers with PLLA nanofibres impregnated with urea fertiliser as the middle layer. Scanning electron microscopy (SEM) and Fourier transform infrared spectrophotometry (FTIR) were employed to characterize the morphology of electrospun nanofibres. Urea release dynamic was analysed using a total nitrogen instrument (TNM-1). The results indicated that triple-layered urea-impregnated nanofibrous structures led to lower initial rate of nitrogen release and slower release rate of cumulative nitrogen which extended for more than three months. It is concluded that triple-layer nanofibrous structures have the potential for slow release delivery of fertilisers.


Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 168 ◽  
Author(s):  
Sikui Liu ◽  
Zhanping Zhang ◽  
Yuhong Qi

Three-component waterborne silicone antifouling coatings, which could cured at room temperature, were prepared, respectively, with cationic (stearyl trimethyl ammonium bromide) or anionic (sodium dodecyl benzene sulfonate) silicone emulsion as a film-forming substance, γ-methacryloxypropyltrimethoxysilane as a curing agent and dibutyltin dilaurate as a catalyst. The effect of emulsifier on the structure and properties of silicone coating was studied. The results showed that the coating with cationic silicone emulsion had high crosslinking density, and its surface is smooth. The surface of the coating prepared by the anionic silicone emulsion is rough. Emulsifier type had no obvious effect on the surface free energy of the waterborne silicone coating. The coatings have the characteristics of low surface energy and excellent bacterial desorption properties. Stearyl trimethyl ammonium bromide in the cured coating can reduce the adhesion of marine bacteria on the coating surface. Both the emulsifiers can inhibit the activity of Navicula Tenera. The waterborne silicone coating prepared by cationic silicone emulsion has better comprehensive mechanical properties and antifouling performance.


Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3067
Author(s):  
Qiang Yang ◽  
Zhanping Zhang ◽  
Yuhong Qi ◽  
Hongyang Zhang

Fouling-release coatings reinforced with micro-alumina and nano-alumina were prepared based on polydimethylsiloxane (PDMS) containing phenylmethylsilicone oil. The surface properties, mechanical properties, leaching behavior of silicone oil, anti-fouling and drag-reduction performance of the coating were studied. The results show that the addition of alumina can significantly improve the tensile strength, elastic modulus and Shore’s hardness of the coating. The adhesion experiments of marine bacteria and Navicula Tenera show that the addition of alumina can reduce the antifouling performance of the coating, which is related to the stripping mode of fouling organisms. The fouling organisms leave the coating surface by shearing, and the energy required for shearing is proportional to the elastic modulus of the coating. At 800–1400 rpm, the addition of alumina will reduce the drag reduction performance of the coating, which is related to the drag reduction mechanism of PDMS. PDMS counteracts part of the resistance by surface deformation. The larger the elastic modulus is, the more difficult the surface deformation is. The experiment of silicone oil leaching shows that the increase of alumina addition amount and the decrease of particle size will inhibit the leaching of silicone oil.


2017 ◽  
Author(s):  
J. Travis Hunsucker ◽  
Harrison Gardner ◽  
Geoffrey Swain

Static immersion studies are commonly used to assess the performance of fouling control coatings. While these tests provide valuable data, it is also of importance to understand the drag forces associated with the accrued fouling communities and the velocities required for fouling removal. Combining the measurements of hydrodynamic testing with those from static immersion testing can help in predicting the performance of coatings prior to their consideration for use on Navy vessels. Replicates of five commercially available coatings (three fouling release coatings and two biocide based coatings) were deployed at two static immersion test sites located along the east coast of Florida (Port Canaveral and Sebastian Inlet). After four months of immersion, the panels were removed, photographed, subjected to known water velocities in a high-speed boat modified for hydrodynamic testing. Each panel was run at 5 m/s for 10 minutes, photographed, and then run at 10 m/s for 10 minutes. The drag forces were measured at speeds of 3, 6, 8.8 and 10 m/s for 1 minute each. Photographs taken before, during, and after hydrodynamic testing were also visually analyzed. After testing adhesion measurements were taken to determine the attachment strength of any hard fouling organisms which remained on the panels. The data collected from this series of tests, enabled the fouling control and fouling release properties of each coating to be characterized.


Marine Drugs ◽  
2020 ◽  
Vol 18 (7) ◽  
pp. 371 ◽  
Author(s):  
Yunqing Gu ◽  
Lingzhi Yu ◽  
Jiegang Mou ◽  
Denghao Wu ◽  
Maosen Xu ◽  
...  

There are a large number of fouling organisms in the ocean, which easily attach to the surface of ships, oil platforms and breeding facilities, corrode the surface of equipment, accelerate the aging of equipment, affect the stability and safety of marine facilities and cause serious economic losses. Antifouling coating is an effective method to prevent marine biological fouling. Traditional organic tin and copper oxide coatings are toxic and will contaminate seawater and destroy marine ecology and have been banned or restricted. Environmentally friendly antifouling coatings have become a research hotspot. Among them, the use of natural biological products with antifouling activity as antifouling agents is an important research direction. In addition, some fouling release coatings without antifoulants, biomimetic coatings, photocatalytic coatings and other novel antifouling coatings have also developed rapidly. On the basis of revealing the mechanism of marine biofouling, this paper reviews the latest research strategies to develop environmentally friendly marine antifouling coatings. The composition, antifouling characteristics, antifouling mechanism and effects of various coatings were analyzed emphatically. Finally, the development prospects and future development directions of marine antifouling coatings are forecasted.


RSC Advances ◽  
2018 ◽  
Vol 8 (18) ◽  
pp. 9910-9921 ◽  
Author(s):  
Mohamed S. Selim ◽  
Hui Yang ◽  
Feng Q. Wang ◽  
Xue Li ◽  
Yong Huang ◽  
...  

The effects of Ag@SiO2core–shell nanofiller dispersion and micro-nano binary structure on the fouling release of silicone paints were studied. An ultrahydrophobic PDMS/Ag@SiO2core–shell nanocomposite was prepared as an antifouling coating material.


Author(s):  
Murray Stewart ◽  
T.J. Beveridge ◽  
D. Sprott

The archaebacterium Methanospirillum hungatii has a sheath as part of its cell wall which is composed mainly of protein. Treatment with dithiothreitol or NaOH released the intact sheaths and electron micrographs of this material negatively stained with uranyl acetate showed flattened hollow tubes, about 0.5 μm diameter and several microns long, in which the patterns from the top and bottom were superimposed. Single layers, derived from broken tubes, were also seen and were more simply analysed. Figure 1 shows the general appearance of a single layer. There was a faint axial periodicity at 28.5 A, which was stronger at irregular multiples of 28.5 A (3 and 4 times were most common), and fine striations were also seen at about 3° to the tube axis. Low angle electron diffraction patterns (not shown) and optical diffraction patterns (Fig. 2) from these layers showed a complex meridian (as a result of the irregular nature of the repeat along the tube axis) which showed a clear maximum at 28.5 A, consistent with the basic subunit spacing.


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