Control of Flow-Induced Electromagnetic Field and Surface Roughness for Enhanced Antibiofouling Activity

Abstract

Microbial fouling involves the physicochemical interactions between microorganisms and solid surfaces. An electromagnetic field (EMF) may change the diffusion rates of microbial cells and the electrical double layer around the cells and contacting surfaces. In the current study, polycardanol exhibiting antibiofouling activity was modified with ferromagnetic iron oxide (IO) to enable the coating to accommodate a stationary magnetic field. The exhibition of magnetic field allowed this study to investigate the EMF effects on bacterial adhesion. The establishment of the electroactive coating decreases the adhesion of bacteria cells to the surface by creating a flow-induced electromagnetic field (FIEMF) based on Faraday's principle of induction. When there was a flow of electrolyte that contained bacterial cells, flow-induced EMF generated according to Faraday’s principle. Morphology of the surface is a critical component to be considered for analyzing different coatings of polycardanol and ferromagnetic polycardanol. The roughness of the coating plays a vital role in developing ferromagnetic polycardanol antibiofouling activity. Therefore, the addition of iron oxide was done in the form of iron oxide ionic solution (IOIS) and iron oxide nanoparticles (IONP) to verify the effects of surface roughness on the antifouling activity. It was observed that the IO-ionic solution (IS)-modified surfaces, with an induced current of 44, 53, 66 nA, showed decreases in the adhesion of bacteria cells more than the unmodified (polycardanol) and IO-nanoparticles-modified ones. The nano-scale uniform roughness of the modified surfaces appeared to play an important role in the reduction of cell adhesion. The results showed that the addition of IOIS reduced the bacterial adhesion more than the addition of IONP due to the surface roughness. The results demonstrated that the IOIS-modified surface (3.2×10-6 mM IO) had the highest antibiofouling activity.