Distinctive Features of the Buffer Capacity of Polyelectrolyte Microcapsules Formed on MnCO₃ Core

Area of Science:

• Materials Science
• Nanotechnology
• Biomedical Engineering

Background:

• Layer-by-layer polyelectrolyte microcapsules (PMCs) require defined buffer capacity (BC) for stable biomedical and materials science applications.
• Manganese carbonate (MnCO3) is a promising core material for hollow structures, but its interaction with polyelectrolytes and effect on BC are not well understood.

Purpose of the Study:

• To determine the buffer capacity (BC) of PMCs templated on MnCO3 cores.
• To investigate the influence of ionic strength and temperature on MnCO3-templated PMCs (PMC_Mn).
• To compare the BC of PMC_Mn with PMCs templated on CaCO3 (PMC_Ca) and polystyrene (PMC_PS) cores.

Main Methods:

• Fabrication of PMCs using layer-by-layer assembly on MnCO3, CaCO3, and PS cores.
• Measurement of BC under varying ionic strength (0.22-3 M NaCl) and temperatures (60-90 °C).
• Comparative analysis of BC performance across different core materials and conditions.

Main Results:

• PMC_Mn exhibited identical BC dynamics in water as PMC_Ca.
• At pH < 5, BC of PMC_Mn and PMC_PS remained constant across ionic strengths; at pH > 8.5, PMC_Mn BC increased only at 3 M NaCl.
• PMC_Mn demonstrated stable BC under heating, while PMC_Ca and PMC_PS showed decreased BC.

Conclusions:

• The core material significantly dictates the functionality and stability of PMCs.
• MnCO3-templated PMCs offer enhanced thermal stability compared to PMC_Ca and PMC_PS.
• These findings support the development of adaptive systems for biosensing and controlled drug delivery.