Ice recrystallisation inhibiting polymer nano-objects via saline-tolerant polymerisation-induced self-assembly

Area of Science:

• Materials Science
• Biotechnology
• Polymer Chemistry

Background:

• Chemical tools to control ice formation are valuable for biotechnology and biomimetic materials.
• Ice binding/antifreeze proteins are key targets for developing such materials.
• Existing methods may face limitations, particularly in saline environments.

Purpose of the Study:

• To introduce novel polymer nanomaterials as potent inhibitors of ice recrystallisation.
• To demonstrate the efficacy of polymerisation-induced self-assembly (PISA) for creating these ice-modulating colloids.
• To investigate the influence of core-forming block chemistry on PISA performance in saline conditions.

Main Methods:

• Utilisation of a poly(vinyl alcohol) graft macromolecular chain transfer agent (macro-CTA) for PISA.
• Engineering the core-forming block with diacetone acrylamide to enable PISA in saline solutions.
• Comparison of ice recrystallisation inhibition activity of synthesized nanoparticles against controls.

Main Results:

• Polymer nanomaterials synthesized via PISA effectively inhibited ice recrystallisation.
• PISA in saline was successful with diacetone acrylamide-containing cores, unlike poly(2-hydroxypropyl methacrylate) cores which caused coagulation.
• The most active nanoparticles inhibited ice growth at concentrations as low as 0.5 mg mL^-1.
• Nanoparticle format demonstrated enhanced activity compared to the PVA stabiliser alone, attributed to dense packing.

Conclusions:

• Polymerisation-induced self-assembly (PISA) provides a viable route to engineer potent ice recrystallisation inhibitors.
• The choice of core-forming block is critical for PISA performance in saline environments.
• These novel polymer nanomaterials offer a unique approach for developing colloids that modulate ice growth, with potential applications in biomimetic materials and cryoprotection.