Engineered biomimetic polymers as tunable agents for controlling CaCO3 mineralization.

Area of Science:

• Materials Science
• Biomimetic Chemistry
• Environmental Science

Background:

• Nature utilizes peptides and proteins for precise control over inorganic mineral formation and carbon dioxide (CO2) sequestration via calcium carbonate (CaCO3) mineralization.
• Understanding these biological mechanisms is crucial for developing advanced materials and environmental solutions.

Purpose of the Study:

• To explore the potential of sequence-specific non-natural polymers, specifically peptoids, as tunable agents for controlling CaCO3 mineralization.
• To investigate the efficiency of peptoids in accelerating CaCO3 formation for CO2 sequestration compared to natural peptides.

Main Methods:

• Synthesized amphiphilic peptoids with hydrophobic and anionic monomers.
• Investigated CaCO3 mineralization in the presence of varying peptoid concentrations and sequences.
• Compared the effects of peptoids with acidic peptides of similar molecular weight on calcite growth morphology and rate.

Main Results:

• Amphiphilic peptoids demonstrated significant control over calcite growth morphology.
• Peptoids achieved an unprecedented 23-fold acceleration of CaCO3 growth at 50 nM concentration.
• Acidic peptides showed much lower enhancement factors (around 2 or less).
• Control over morphology and growth rate was dependent on peptoid sequence, side-chain chemistry, chain length, and concentration.

Conclusions:

• Sequence-specific non-natural polymers (peptoids) can effectively mimic and enhance the functions of natural peptides/proteins in directing CaCO3 mineralization.
• Peptoids offer a tunable platform for developing advanced materials for CO2 sequestration through mineral trapping.
• These findings provide a foundation for designing synthetic polymers for biomimetic mineralization applications.