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Polydimethylsiloxane (PDMS) with exceptional fouling-release properties is extremely susceptible to the microfouling resulted from the colonization of the pioneer microorganisms in the marine environment. In this study, six carboxyl-modified multi-walled carbon nanotubes (cMWNTs) nanoparticles were incorporated into the PDMS matrix, respectively, in order to produce the cMWNTs-filled PDMS nanocomposites (CPs) with improved antifouling (AF) properties. The AF properties of the six CPs were examined via the field assays conducted in Weihai, China. The effects of the anti-biofouling potential of the CPs (i.e. the P3 surface) on the colonization of the pioneer prokaryotic and eukaryotic microbes were investigated using the single-stranded conformation polymorphism technique via the comparison of the diversity indices. Different CPs have displayed differential and better AF properties as compared to that of the unfilled PDMS (P0). The P3 surface has exhibited exceptional anti-biofouling capacity compared with the other CPs surfaces, which can effectively prevent biofouling for more than 14 weeks in the field. The SSCP analysis revealed that the P3 surface may have significant modulating effect on the pioneer microbial communities. The pioneer eukaryotic microbes seemed more susceptible than the pioneer prokaryotic microbes to be subjected to the major perturbations exerted by the P3 surface. The dramatically reduced eukaryotic-microbial diversity may contribute to the impeding and weakening of the development and growth of the biofilm. The P3 surface has the potential to be used for future maritime applications.

In the current study, six carboxyl-modified multi-walled carbon nanotubes (cMWNTs)-filled PDMS nanocomposites (CPs) were successfully prepared, respectively. The antifouling (AF) properties of the CPs surfaces were evaluated via the long-term field immersion assays. The effects of the CPs surfaces on the attachment and colonization of the pioneer biofilm communities were investigated using the single-strand conformation polymorphism (SSCP) technique via the comparison of the diversity indices. Different CPs surfaces (i.e. the P1–P6surfaces) have exhibited differential and excellent AF properties in the sea trial test as compared to that of the unfilled PDMS (P0) surface, indicating that the six cMWNT nanoparticles (i.e. the C1–C6 fillers) have demonstrated better AF properties, when used as reinforcing fillers in the PDMS matrix. The only reinforcing cMWNT filler (i.e. the C3 filler, 50 nm diameter, 10–20 μm length) has been identified and determined in the field. In addition, the partially aggregated cMWNT filler in the PDMS matrix was found to contribute to the improved AF properties of the CPs. The CPs surfaces can significantly reduce the adherent pioneer eukaryotic community diversity and richness, which may have dramatically modulating effect on the attachment and colonization of pioneer eukaryotic microbes. In contrast, most CPs (i.e. the P1–P5surfaces) can only exert slight perturbation effect on the pioneer prokaryotic communities. Only the P6surface can exert significant perturbation effect on the adherent pioneer prokaryotic and eukaryotic communities at the same time. The functionalized CPs surfaces may have the potential to be used for future maritime applications. [ABSTRACT FROM PUBLISHER]

Microbial biofilm formation on composite surfaces has posed potential threats to the composite's structural integrity, durability and physical properties. Pioneer eukaryotes have been reported to be primarily responsible for the degradation of a wide range of composite materials. In this study, different carbon nanotubes (CNTs) were incorporated in the polydimethylsiloxane (PDMS) matrix respectively, in order to create CNTs-filled PDMS composites (PCs) with improved anti-biofouling properties. The anti-biofouling properties of pure PDMS (P0) and PCs were examined through marine field assays. The diversity and richness of pioneer eukaryotic communities adhering to P0 and PCs surfaces were analyzed using the single-strand conformation polymorphism (SSCP) technique. PCs have exhibited differential and better anti-biofouling properties, when compared to the PDMS control. Two PCs with exceptional anti-biofouling properties were determined in the field. The Shannon diversity index and species richness of pioneer eukaryotic communities on most PCs surfaces were dramatically lower than those of the pure PDMS control (P < 0.05). This indicates a significant decrease in the diversity and richness of pioneer eukaryotic communities. The combined results suggest PCs can effectively reduce the colonization of pioneer eukaryotes, such as algae sporelings and invertebrate larvae. PCs with low cost and good compatibility in the marine environment give the potential for future anti-biofouling applications. [ABSTRACT FROM AUTHOR]

In this study, the antifouling (AF) performance of different carbon nanotubes (CNTs)-modified polydimethylsiloxane (PDMS) nanocomposites (PCs) was examined directly in the natural seawater, and further analyzed using the Multidimensional Scale Analyses (MDS) method. The early-adherent bacterial communities in the natural biofilms adhering to different PC surfaces were investigated using the single-stranded conformation polymorphism (SSCP) technique. The PCs demonstrated differences and reinforced AF properties in the field, and they were prone to clustering according to the discrepancies within different CNT fillers. Furthermore, most PC surfaces only demonstrated weak modulating effects on the biological colonization and successional process of the early bacterial communities in natural biofilms, indicating that the presence of the early colonized prokaryotic microbes would be one of the primary causes of colonization and deterioration of the PCs. C6 coating seems to be promising for marine AF applications, since it has a strong perturbation effect on pioneer prokaryotic colonization. [ABSTRACT FROM AUTHOR]

In this paper, two carbon nanotube (CNT) nanofillers, namely the multi-walled carbon nanotubes (MWCNTs) and the carboxyl-modified MWCNTs (cMWCNTs), were introduced into the polydimethylsiloxane (PDMS) matrix respectively, in order to produce the PDMS composites with reinforced anti-biofouling properties. The anti-biofouling capacity of the silicone-based coatings, including the unfilled PDMS (P 0 ), the MWCNTs-filled PDMS (P M ) and the cMWCNTs-filled PDMS (P C ), was examined via the field assays conducted in Weihai, China. The effect of different silicone-based coatings on the dynamic variations of the pioneer microbial-community diversity was analyzed using the single-strand conformation polymorphism (SSCP) technique. The P M and P C surfaces have exhibited excellent anti-biofouling properties in contrast to that of the PDMS surface, with extremely low attachment of the early colonizers, such as juvenile invertebrates, seaweeds and algae sporelings. The P M and P C surfaces can effectively prevent biofouling for more than 12 weeks. These combined results suggest that the incorporation of MWCNTs or cMWCNTs into the PDMS matrix can dramatically reinforce its anti-biofouling properties. The SSCP analysis reveals that compared with the PDMS surfaces, the P M and P C surfaces have strong modulating effect on the pioneer prokaryotic and eukaryotic communities, particularly on the colonization of pioneer eukaryotic microbes. The significantly reduced pioneer eukaryotic-community diversity may contribute to the weakening of the subsequent colonization of macrofoulers. [ABSTRACT FROM AUTHOR]

Chlorinated rubber (CR)-based materials available for artificial surfaces have important commercial and industrial applications. However, CR-based materials are susceptible to diverse biofouling. In this study, different amounts (i.e. 0.2 wt % and 2 wt %) of multi-walled carbon nanotubes (MWCNTs) were incorporated into the CR matrix (CF 0), respectively, in order to prepare the MWCNTs-modified CR composites (MCRCs, CF 1 and CF 2) with improved antifouling (AF) properties. The CR-based coatings were characterized using the SEM technique and then examined in the natural seawater via long-term field exposure assays. The impact of MCRCs on the colonization dynamics of pioneer eukaryotic microbes (PEM) in the natural biofilms with regard to their diversity, abundance, distribution patterns and succession process was investigated using the single-stranded conformation polymorphisms (SSCP) technique. MCRCs demonstrated differential surface structure features and enhanced AF properties compared with the unfilled CR matrix. The diversity and abundance of the PEM on the MCRC surfaces were found to be lower than that of the CR matrix, particularly reduced on the CF 2 surfaces (P < 0.05); while the dominant population of PEM on the MCRCs was significantly higher than that of the CR matrix (P < 0.05). This indicated the colonization of the PEM on MCRC surfaces was greatly perturbed by the incorporation of MWCNTs in the CR matrix, as well supported by the reduced Evenness index and the clustering patterns. It seems that MWCNTs incorporated in the CR matrix would result in differential surface structures, enhanced AF properties and reinforced perturbation effect on PEM, which would further impede the development of natural biofilms and conduce to the prevention of macrofouling formation. MCRCs would have potential applications in future coating industries for biofouling mitigation. • MWCNTs-modified chlorinated rubber-based composites (MCRCs) for anti-biofouling applications were prepared. • The MCRCs have decent AF properties as determined in the field. • MCRCs can reduce the diversity and abundance of pioneer eukaryotic microbes. • MCRCs can impede the development of natural biofilms and prevent macrofouling. • The possible mechanisms of MCRCs against biofouling were explored. [ABSTRACT FROM AUTHOR]