Dynamic Implications of Noncovalent Interactions in Amphiphilic Single-Chain Polymer Nanoparticles

Area of Science:

• Polymer Science
• Biomaterials Engineering
• Soft Matter Physics

Background:

• Single-chain polymer nanoparticles (SCNPs) are versatile biomimetic materials.
• Their structure and function depend on polymer chain segment mobility.
• Quantifying noncovalent interactions' influence on SCNP dynamics is challenging.

Purpose of the Study:

• To investigate how different noncovalent interactions affect SCNP structure and dynamics.
• To synthesize and characterize SCNPs with varying interaction strengths.
• To understand the relationship between local interactions and polymer dynamics.

Main Methods:

• Synthesis of amphiphilic copolymers with specific interaction-forming monomers.
• Characterization of SCNP structure using size exclusion chromatography and small-angle neutron scattering.
• Analysis of polymer dynamics via dynamic light scattering and neutron spin echo spectroscopy.
• Application of the Zimm with internal friction (ZIF) model.

Main Results:

• SCNPs formed folded structures similar to intrinsically disordered proteins.
• Polymer dynamics were accurately described by the ZIF model.
• Noncovalent interactions additively restricted internal polymer relaxations.
• Local scale interactions effectively controlled SCNP polymer dynamics.

Conclusions:

• Noncovalent interactions play a critical role in dictating SCNP structure and dynamics.
• The ZIF model successfully captures the influence of these interactions.
• This work provides a framework for designing functional biomimetic materials with controlled properties.