Sequence of Hydrophobic and Hydrophilic Residues in Amphiphilic Polymer Coatings Affects Surface Structure and Marine Antifouling/Fouling Release Properties

Abstract

Amphiphilic polymers, specifically combinations of hydrophilic and hydrophobic residues, have been shown to be effective as antifouling materials against the algae Ulva linza and Navicula diatoms. Here we use the inherent sequence specificity of polypeptoids made by solid-phase synthesis to show that the sequence of hydrophilic (methoxy) and hydrophobic (fluorinated) moieties affects both antifouling and fouling release of U. linza. The platform used to test these sequences was a polystyrene-bpoly(ethylene oxide-co-allyl glycidyl ether) (PS-b-P(EO-co-AGE)) scaffold, where the polypeptoids are attached to the scaffold using thiol−ene click chemistry. The fluorinated moiety is very surface active and directs the surface composition of the polymer thin film. The position and number of fluorinated groups in the polypeptoid are shown to affect both the surface composition and antifouling properties of the film. Specifically, the position of the fluorinated units in the peptoid chain changes the surface chemistry and the antifouling behavior, while the number of fluorinated residues affects the fouling-release properties.

Amphiphilic Polymer Platforms: Surface Engineering of Films for Marine Antibiofouling

“…With the aim to develop films for AF/FR of marine species, a polystyrene‐ b ‐poly(ethyleneoxide‐ co ‐allylglycidyl ether) (PS‐P(EO‐ co ‐AGE)) block copolymer was functionalised via thiol‐ene click chemistry with a thiol‐terminated peptoid composed of the aformentioned fluorinated and methoxyethyl N ‐glycine residues (Figure ) . It was found that the number of the highly surface‐active fluorinated moieties influenced the surface composition as well as the AF/FR performance (Figure ).…”

Evaluation of cationic micropeptides derived from the innate immune system as inhibitors of marine biofouling

“…Other interesting alternative approaches to AF involve nontoxic polymer coatings that either deter the settling organism from adhering or weaken the interactions between the organism and the surface, allowing their removal via hydrodynamic shear forces . The promising recent developments of amphiphilic polymers made from copolymerised peptoids as fouling release coatings and also other hydrophobic coatings displaying linked quaternary ammonium groups suggest that the concept of cationic amphiphilic peptides may be display interesting AF properties in several areas Majumdar, Lee, Patel, Ward et al 2008;Martinelli et al 2011;Lejars et al 2012;van Zoelen et al 2014). …”

Synthesis of Macromolecules Containing Phenylalanine and Aliphatic Building Blocks

“…While the control of the microstructure of polymers still remains a challenge for polymer chemists, the ability to tune the sequence of polymers would be an asset for applications in materials sciences. For example, van Zoelen et al reported the preparation of sequence‐specific polypeptoids based on hydrophobic and hydrophilic units used as coating on a surface . The authors demonstrated that the sequence had an effect on the antifouling or fouling release properties of this coating.…”