Surface Modification of Polydopamine Particles with Polyethyleneimine Brushes for Enhanced Stability and Reduced...

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Polydopamine (Pdop) particles exhibit valuable properties but are unstable in water due to fragment release.
• This instability limits their practical applications in various fields.

Purpose of the Study:

• To enhance the stability and reduce fragmentation of polydopamine particles.
• To investigate surface engineering strategies, including polyelectrolyte multilayer (PEM) coating and polyelectrolyte (PE) brush grafting.

Main Methods:

• Polydopamine particles were surface-modified using PEM coating and PE brush grafting.
• Polyethyleneimine (PEI) was used as the grafting polymer, with varying grafting densities.
• Particle stability was assessed by measuring fragment release across a range of pH values.

Main Results:

• PEI brush grafting was more effective than PEM coating in suppressing Pdop fragment release.
• Long-chain PEI grafted Pdop particles showed over 90% inhibition of fragment release across pH 3-9.
• A direct correlation was found between PEI grafting density and particle stability, with higher densities improving stability.

Conclusions:

• Surface engineering, particularly PEI brush grafting, significantly enhances the stability of polydopamine particles.
• Optimized PEI grafting offers a robust method to prevent polydopamine fragmentation.
• These stabilized Pdop particles hold promise for diverse technological applications.