Anti-Biofouling Properties of Comblike Block Copolymers with Amphiphilic Side Chains

Abstract

Surfaces of novel block copolymers with amphiphilic side chains were studied for their ability to influence the adhesion of marine organisms. The surface-active polymer, obtained by grafting fluorinated molecules with hydrophobic and hydrophilic blocks to a block copolymer precursor, showed interesting bioadhesion properties. Two different algal species, one of which adhered strongly to hydrophobic surfaces, and the other, to hydrophilic surfaces, showed notably weak adhesion to the amphiphilic surfaces. Both organisms are known to secrete adhesive macromolecules, with apparently different wetting characteristics, to attach to underwater surfaces. The ability of the amphiphilic surface to undergo an environment-dependent transformation in surface chemistry when in contact with the extracellular polymeric substances is a possible reason for its antifouling nature. Near-edge X-ray absorption fine structure spectroscopy (NEXAFS) was used, in a new approach based on angle-resolved X-ray photoelectron spectroscopy (XPS), to determine the variation in chemical composition within the top few nanometers of the surface and also to study the surface segregation of the amphiphilic block. A mathematical model to extract depth-profile information from the normalized NEXAFS partial electron yield is developed.

Surface Sensing and Settlement Strategies of Marine Biofouling Organisms

“…Such inert coatings have been identified for a number of well-defined surfaces in short term, single species assays. Especially ethylene glycol (EG) x -containing coatings have been used in the biomedical area [21][22][23][24] and have recently been investigated with respect to their marine anti-fouling potential [25][26][27][28][29][30][31][32][33]. However, the degradation of the ethylene-glycol-containing chemistries makes them unsuitable for long-term antifouling applications [34,35].…”

“…However, the degradation of the ethylene-glycol-containing chemistries makes them unsuitable for long-term antifouling applications [34,35]. Other promising approaches involve the use of amphiphilic [26,27,29,36] or zwitterionic chemistries [37][38][39][40]. Even though fouling inhibition is the most desirable way of avoiding biofouling, the development of such inert, non-toxic, and long-term stable coatings remains to be the most challenging of the three approaches.…”

Block Copolymer Membranes for Aqueous Solution Applications

“…Cho et al 29 synthesized amphiphilic copolymers with side chains of hydrophilic PEO blocks and hydrophobic blocks of polystyrene (PS) and polyisoprene (PI) with clear decrease of the number of attached microalga and diatom cells as the PEO content of increased. A similar approach using ethoxylated fluoroalkyl side chains were previously used with success 30,31 . Copolymers with zwitterionic segments have been explored by other groups.…”

Combining theory and experiment for X-ray absorption spectroscopy and resonant X-ray scattering characterization of polymers

“…Since NEXAFS is sensitive to specific functional groups and bonds, materials that are composed of the same elements, for example polystyrene and polyethylene which both contain just carbon and hydrogen, can have very distinct NEXAFS profiles. NEXAFS is itself a useful tool in polymer science, and has been widely used to examine thin film properties such as surface composition [15][16][17][18] and molecular orientation in ordered polymers [19][20][21][22][23]. Furthermore, absorption differences between polymers can be utilized for chemical sensitivity in real space imaging of thin films via scanning transmission X-ray microscopy (STXM) [24][25][26][27][28][29][30][31].…”