Polysiloxane-based block copolymers with marine bacterial anti-adhesion properties

Area of Science:

• Polymer Chemistry
• Materials Science
• Marine Biology

Background:

• Marine biofouling poses significant challenges for submerged structures.
• Developing effective anti-fouling coatings is crucial for marine applications.
• Block copolymers offer tunable properties for surface modification.

Purpose of the Study:

• Synthesize and characterize novel di- and triblock copolymers of PDMS and PMASi.
• Evaluate the anti-adhesive and anti-fouling performance of these copolymers.
• Correlate coating properties with their anti-fouling efficacy.

Main Methods:

• Synthesis of block copolymers using macro-RAFT agents.
• Characterization of molar mass, dispersity, and glass transition temperatures.
• Contact angle measurements to determine surface free energy.
• Laboratory assays against marine bacteria (Pseudoalteromonas sp., Shewanella sp.).
• Field assays to assess antifouling performance.

Main Results:

• Block copolymers with predictable molar masses and low dispersities (Đ < 1.2) were synthesized.
• Surface free energies as low as 15.0 mJ m⁻² were achieved.
• PDMS-based block copolymer coatings showed superior anti-adhesive properties compared to PMASi-only coatings.
• Diblock copolymer coatings exhibited better field antifouling performance than triblock copolymers.
• Antifouling properties correlated with higher receding water contact angles.

Conclusions:

• PDMS-PMASi block copolymers are promising materials for anti-fouling coatings.
• Coating composition and architecture (diblock vs. triblock) influence performance.
• Surface properties, particularly receding water contact angle, are key indicators of antifouling efficacy.