Model Amphiphilic Block Copolymers with Tailored Molecular Weight and Composition in PDMS-Based Films to Limit Soft...

Area of Science:

• Materials Science
• Polymer Chemistry
• Surface Science

Background:

• Biofouling presents significant challenges in marine environments, impacting structures and increasing operational costs.
• Developing effective antifouling and fouling-release surfaces is crucial for marine applications.
• Amphiphilic block copolymers offer tunable surface properties for controlling interfacial interactions.

Purpose of the Study:

• To create and characterize polymer films with controlled surface compositions for antifouling and fouling-release applications.
• To evaluate the performance of these films against two types of algae with different surface adhesion preferences.
• To correlate surface chemistry and morphology with observed biological performance.

Main Methods:

• Production of polymer films using amphiphilic block copolymers (oligo(ethylene glycol) - PEGMA and fluoroalkyl - AF6) in a poly(dimethylsiloxane) network.
• Assessment of antifouling and fouling-release properties using assays with Ulva linza and Navicula incerta.
• Surface characterization using captive bubble contact angle, atomic force microscopy, and near edge X-ray absorption fine structure spectroscopy.

Main Results:

• All films demonstrated good performance against Ulva linza, with lower molecular weight block copolymers showing superior fouling-release.
• Optimal performance was observed with AF6/PEGMA side group ratios between 50:50 and 60:40, leading to spontaneous removal of some algae.
• Navicula incerta cells were also removed from several of the tested coating compositions.
• Surface characterization correlated film chemistry and morphology with the observed antifouling efficacy.

Conclusions:

• Controlled surface chemistry using amphiphilic block copolymers in a polymer network can yield effective antifouling and fouling-release properties.
• The molecular weight and composition ratio of the block copolymers are critical factors in determining performance against different fouling organisms.
• These findings provide a pathway for designing advanced marine coatings with tailored anti-biofouling capabilities.