Hydration behaviors of nonfouling zwitterionic materials

Area of Science:

• Materials Science
• Surface Chemistry
• Biomaterials Science

Background:

• Zwitterionic materials are recognized for their exceptional ultralow fouling properties.
• The precise mechanism behind their fouling resistance is not fully understood.
• Understanding this mechanism is key to designing advanced antifouling surfaces.

Purpose of the Study:

• To elucidate the fouling-resistant mechanism of zwitterionic materials.
• To investigate the role of hydration and molecular structure in fouling resistance.
• To establish design principles for enhanced antifouling performance.

Main Methods:

• Utilized ab initio molecular dynamics simulations to model hydration behavior.
• Employed surface-sensitive sum frequency generation vibrational spectroscopy for experimental validation.
• Studied trimethylamine-N-oxide (TMAO) and carboxybetaines with varying charge-separation distances.

Main Results:

• Fouling resistance is governed by the interplay of hydrogen bonding, net charge, and dipole moment.
• Shortened zwitterionic spacing enhances water hydrogen bonding and structural stability.
• Reduced charge separation decreases interactions with biofoulers, boosting fouling resistance.

Conclusions:

• Optimizing zwitterionic spacing is critical for superior antifouling performance.
• Trimethylamine-N-oxide (TMAO) demonstrates excellent nonfouling characteristics due to its minimal spacing, strong hydrogen bonding, and low net charge/dipole moment.
• The findings provide a design principle for developing next-generation ultralow fouling materials.