The effect of high voltage pulse electric field (HPEF) on attachment of diatom on graphene composite coating and carbon fiber composite coating in marine environment

With increasing restrictions of environmental regulations and safety concerns on the traditional poisonous coatings, it is highly desirable to develop a new green anti-biofouling method in marine environment. In this paper, graphene composite coating and carbon fiber (CF) composite coating connected with high voltage pulse electric field (HPEF) were developed to inhibit the attachment of diatoms. The polarizing microscopy showed that the attachment rates of Thalassiosira and Navicula reached the lowest levels which were 0.23 cells mm−2 and 6.06 cells mm−2 on the graphene composite coating, 0.38 cells mm−2 and 4.17 cells mm−2 on the CF composite coating, under the HPEF with 1 h duration, 23.15 kHz frequency, 0.5 duty cycle and 19 kV pulse amplitude. While the attachment rates of Thalassiosira and Navicula were 21.21 cells mm−2 and 61.89 cells mm−2 on the graphene composite coating, 22.75 cells mm−2 and 62 cells mm−2 on the CF composite coating, without HPEF. Scanning electron microscopy (SEM) revealed that HPEF disintegrated the diatom cells, which could underlie the considerable inhibition of the diatom attachment by the HPEF. Additionally, the hardness, flexibility and shock resistance tests indicated that graphene and CF could considerably increase the mechanical properties of epoxy resin coating. HPEF stimulation had no obvious effect on the mechanical properties of the composite coatings.