Magnetic Slippery Anti-Biofouling Surfaces
Abstract
In this research program, through disruptive experimental studies and theoretical analysis,we intend to (I) develop self-healing ma""gnetic anti-biofouling surfaces, (II) study smallscalefundamentals of biofouling on these surfaces through Scanning Probe Microscop""y(SPM), and (III) examine the settlement and adhesion of bacterial films, diatoms andbarnacles on these surfaces under marine envi"ronments. This research program willprovide a fundamental platform for continuing studies in this field.3.1. Task 1: Development of Magnetic Anti-Biofouling SurfacesThe concept of magnetic slippery surfaces (MAGSS) was recently developed by the PI and thesuper"ior performance of these surfaces for anti-icing and anti-scaling is demonstrated, Fig. 2.Based on the same concept, here, we propo"sea new generation of anti-biofouling surfaces.These surfaces are made of two components(1) a thin film of magnet with the thickn"ess of50 !"" which will be deposited on a substrateand (2) a non-Newtonian magnetic fluid, Fig.1. The magnetic fluid is permanentl"y lockedon the substrate through the imposed magneticforce as shown in Fig. 1. The high viscosity ofthe non-Newtonian magnetic fluid leads tosuperior stability of these surfaces under highshear flows2. The non-Newtonian fluid has aPolydimethylsiloxane (PDMS)" base withdispersed magnet nanoparticles of Nd2Fe14B.PDMS was chosen due to its inert, non-toxic,non-flammable nature. The choice"" of Nd2Fe14Bnanoparticles is based on their highmagnetization. To resemble the outer surfaceof hull, we use a metal surface as th""eunderlying substrate. In the first step, we applythe thin film magnet to the metal substrate.Thin film magnet with various magne"tic fields(20-100 mT) will be examined. The magnitude of magnetic field affects formation of liquidliquidinterface2. The non-Newtonian magnetic fluid will be prepared in the PI~s group and willbe deposited on the thin films. The properties of magnetic slippery" surfaces including interfacialenergy, rheological properties, and chemical composition will be tuned in this research program.Onc""e these surfaces are developed, the interfacial energy of these surfaces will be measured inthe PI laboratory through JKR method al""ong with contact angle measurements. Also, rheologicalcharacteristics of these surfaces will be assessed through Tensiometer in the" PI group. Thedeveloped surfaces will be examined in Task 3 for their interactions with marine species.3.2. Task 2: Fundamental St"udies on Anti-Biofouling SurfacesHere, we focus on nano-scale adhesion of bio-species on anti-biofouling surfaces and comparephysi"cs of adhesion between solid-liquid and liquid-liquid interfaces. The energy required toreplace a solid-water interface with a soli"dbiologicalmatter interface controls attachmentand spread of fouling in marine environment.As discussed above, the initial stage"" ofbiofouling includes the attachment ofmolecules such as polysaccharides, proteinsand proteoglycans on the surface. If theinter""facial energy of these bio-species on thesurface can be reduced, further biofoulingproblem can be avoided. To acquire knowledge on"" the adhesion of these bio-species on thesurface, here, we will use Scanning Probe Microscopy (SPM) in the liquid environment in th""ePI~s group, Fig. 3. In this platform, the adhesion energy of bio-species in nano-scale on a surfacecan be probed. We will use sev""eral control samples (PDMS elastomers such as Silastic T2,Sylgard 184, and Intersleek) to compare their performance with the magnet""ic anti-biofoulingsurface. Note that control samples form a solid-liquid interface, while the proposed surface hereform a liquid-l""iquid interface. Initially, diatoms will be cultured on the samples in artificialseawater containing ~Tropic Marine~ sea salt (Aqua""rientechnik GmbH), supplemented withnutrients to form Guillard~s (F/2) solution (Sigma Aldrich). The culture process occurs at 18 o"Cwith a 16:8 light:dark cycle. The samples will be equilibr
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 29, 2017
- Source ID
- N000141712978
Entities
People
- Hadi Ghasemi
Organizations
- Office of Naval Research
- United States Navy
- University of Houston System