Bio-inspired Surfaces for Fouling Resistance, A Review

Abstract

Fouling causes serious problems in daily lives and mass industrial processes. Modern industry has made lots of artificial anti-fouling surfaces especially bio-inspired surfaces with some effective strategies to tackle the fouling issue. These surfaces inspired by natural creatures like lotus and sharks show both highefficiency and eco-friendly properties. This review discusses the model behind the anti-fouling properties, the mechanism of various types of fouling, and the strategy of both natural and bio-inspired surfaces. Also, the possibility of building a wide-range anti-fouling and durable surface is discussed.

A review of bio-inspired fouling resistance surfaces

“…For example, the artificial surfaces inspired by both lotus leaf and shark skin have strong hydrophobicity. They are resistant to much organic fouling but do not resist other kinds of fouling, like ice [8].…”

“…The surface energy is the energy required to break intermolecular force, mainly Van der Waals force, for creating a new surface [9], and the adhesion between fouling materials and texture, called the work of adhesion, would be weaker if the surface energy is lowered. The relationship between the work of adhesion and the interfacial free energy of a surface (γ s 1 v ) would be illustrated by the equation Wa = γ s 1 v + γ s 2 v − γ s 1 s 2 , and the γ s 2 v and γ s 1 s 2 are the interfacial free energy for fouling-substrate interface and the fouling [8]. In the case of reducing the surface energy, many modifications, including plasma treatment and polymer blending, would be done [9].…”

“…Fluorine has strong electronegativity, and the CF bond is polar, so the electrons are harder to move far away from fluorine atoms, and the surface energy would be low. The surface chemistry interacting specifically with the fouling would also function well [8]. Enzymes on the surface could diminish the attachment intensity of barnacles and other organic fouling [4], and the toxic-releasing surface, like Nitric oxide-releasing materials, could release NO adhered to a character or contained in a polymeric delivery agent to kill the bacteria [10,11].…”

“…The second strategy for antifouling surface design is the modification of the microstructure. Although the microstructure is a crucial component for preventing liquid fouling and many fouling with low modulus [3,8], like in the case of resisting solid fouling with high modulus [3,8], the microstructure would be considered detrimental [3][4][5][6][7]. The adhesion of the most common foulants would be increased by the roughness and topography of materials.…”

“…As mentioned previously, when the fouling has a high modulus, the surface using this approach would be designed to lower the roughness of the surface so the fouling would be less likely to attach. Taking the SLIPS structure, the structure used by the pitcher plant, as an example, the Slippery Liquid-Infused Porous Surfaces has many porous containing liquid or topography to create the slippery surface so that the fouling would be easily removed and hard to attach [8]. The principle of SLIPS will be shown in the chapter below.…”