Superhydrophobic and Superhydrophilic Nanocomposite Coatings for Preventing Microbial Adhesion in Liquid Food Flow Channel

摘要

Many recent studies have shown that both superhydrophobic (SB) and superhydrophilic (SL) coatings can minimize microbial adhesion on solid substrates; however, a comprehensive investigation of both extreme surface characteristics is not available. Therefore, the aim of this paper is to test and evaluate the rate of microbial adhesion on liquid transport system by comparing the effects of SB and SL coatings. Water contact angles on control, SB and SL surfaces were 70°, 150° and 0°, respectively. For adhesion experiments, the suspension of 3×10~8 cells/ml Escherichia coli K-12 was pumped through the chamber at two flow rates of 0 and 200 ml/min. Increases in flow rate and hydrodynamic force significantly inhibited the bacterial adhesion on both developed surfaces. After running for an hour, the fluorescence intensities (FIs) of adhered bacteria on SB and SL surfaces were up to 80 and 65% lower than uncoated surface, depending upon the surface wetability.