New anti-biofouling carbon nanotubes-filled polydimethylsiloxane composites against colonization by pioneer eukaryotic microbes

• Anti-biofouling properties of PDMS can be significantly improved by incorporating 0.1% (w/w) CNT nanoparticles.
• Two PDMS composites with exceptional anti-biofouling properties were determined.
• The effect of PDMS composites on the diversity and richness of pioneer eukaryotic communities was studied.
• Most PDMS composites can dramatically reduce the colonization of pioneer eukaryotic microbes.

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.