Antifouling Potential of Lubricious, Micro-engineered, PDMS Elastomers against Zoospores of the Green Fouling AlgaUlva (Enteromorpha)

Abstract

The settlement and release of Ulva spores from chemically modified, micro-engineered surface topographies have been investigated using poly(dimethyl siloxane) elastomers (PDMSe) with varying additions of non-network forming poly(dimethyl siloxane) based oils. The topographic features were based on 5 microns wide pillars or ridges separated by 5, 10, or 20 microns wide channels. Pattern depths were 5 or 1.5 microns. Swimming spores showed no marked difference in settlement on smooth surfaces covered with excess PDMS oils. However, incorporation of oils significantly reduced settlement density on many of the surfaces with topographic features, in particular, the 5 microns wide and deep channels. Previous results, confirmed here, demonstrate preferences by the spores to settle in channels and against pillars with spatial dimensions of 5 microns, 10 microns and 20 microns. The combination of lubricity and pillars significantly reduced the number of attached spores compared to the control, smooth, unmodified PDMSe surfaces when exposed to turbulent flow in a flow channel. The results are discussed in relation to the energy needs for spores to adhere to various surface features and the concepts of ultrahydrophobic surfaces. A factorial, multi-level experimental design was analyzed and a 2nd order polynomial model was regressed for statistically significant effects and interactions to determine the magnitude and direction of influence on the spore density measurements between factor levels.

Soft matter with hard skin: From skin wrinkles to templating and material characterization

“…74 For instance, HoipkemeirerWilson and coworkers reported that topographically corrugated surfaces are capable of reducing biofouling. 75 The degree to which fouling was reduced was found to depend on the dimensions of the geometrical protrusions as well as the chemistry of the surfaces. Because biofouling includes a very diverse range of various species, whose sizes span several orders of magnitude, one single topographical pattern will not likely perform as an effective antifouling surface.…”

Impact of engineered surface microtopography on biofilm formation of Staphylococcus aureus

“…29 Silastic® brand silicone elastomers are biomaterials used in numerous medical devices including tubing, catheters, and pacemaker leads. The elastomer was prepared by mixing one part by weight of curing agent with ten parts by weight of resin, then degassing under vacuum ͑28-30 in.…”

Effect of contact angle hysteresis on the removal of the sporelings of the green alga Ulva from the fouling-release coatings synthesized from polyolefin polymers

“…A number of investigations have explored the relationship between water contact angle and surface free energy of polymeric substrates with the settlement ͑attachment͒ and/or adhesion strength of various marine organisms. [15][16][17][18][19][20][21] Generally, for a wide range of organisms, there is a good correlation between low surface energy of the coating and enhanced fouling-release performance ͑i.e., low adhesion strength͒, although there are exceptions, notably for marine diatoms, which adhere more strongly to hydrophobic surfaces. 22 The green seaweed Ulva is the most common macroalgae that fouls man-made structures, including boats, buoys, ships, and submarines, and which reproduces by the production of vast numbers of microscopic motile spores ͑zoospores͒.…”