Critical Amphiphilic Concentration: Effect of the Extent of Amphiphilicity on Marine Fouling-Release Performance

• Published in: Langmuir Vol. 37; no. 8; pp. 2728 - 2739
• Main Authors: Rahimi, AliReza, Stafslien, Shane J, Vanderwal, Lyndsi, Bahr, James, Safaripour, Maryam, Finlay, John A, Clare, Anthony S, Webster, Dean C
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 02-03-2021
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/acs.langmuir.0c03446

Amphiphilic surfaces, containing both hydrophilic and hydrophobic domains, offer desirable performance for many applications such as marine coatings or anti-icing purposes. This work explores the effect of the concentration of amphiphilic moieties on converting a polyurethane (PU) system to a coating having fouling-release properties. A novel amphiphilic compound is synthesized and added at increasing amounts to a PU system, where the amount of the additive is the only variable in the study. The additive-modified surfaces are characterized by a variety of techniques including ATR-FTIR, XPS, contact angle measurements, and AFM. Surface characterizations indicate the presence of amphiphilic domains on the surface due to the introduction of the self-stratifying amphiphilic additive. The fouling-release properties of the surfaces are assessed with three biological assays using Ulva linza, Cellulophaga lytica, and Navicula Incerta as the test organisms. A change in the fouling-release performance is observed and plateaued once a certain amount of amphiphilicity is attained in the coating system, which we call the critical amphiphilic concentration (CAC).