Three distinct open-pore morphologies from a single particle-filled polymer blend.

Area of Science:

• Materials Science
• Polymer Science
• Colloid Science

Background:

• Ternary mixtures of polymers and particles are crucial in materials science.
• Controlling porous morphology is key for material properties and applications.
• Understanding the role of interfacial tension is vital for material design.

Purpose of the Study:

• To investigate the formation and stability of porous morphologies in polyisobutylene (PIB), polyethylene oxide (PEO), and silica ternary mixtures.
• To elucidate the distinct roles of interfacial tension in stabilizing different morphologies.
• To assess the processability and generalizability of the observed porous structures.

Main Methods:

• Systematic variation of mixture composition (PIB, PEO, silica).
• Microscopy and rheological analysis to characterize morphology.
• Interfacial tension measurements and theoretical analysis.

Main Results:

• Three distinct open-pore morphologies were identified: pendular network, capillary aggregate network, and cocontinuous morphology.
• Interfacial tension plays varied roles: stabilizing the pendular network, having no effect on the capillary aggregate network, and destabilizing the cocontinuous morphology.
• All three morphologies exhibit pore stability under flow and are amenable to processing.

Conclusions:

• The composition of PIB/PEO/silica mixtures dictates distinct porous morphologies.
• Interfacial tension's role is morphology-dependent, offering tunable control.
• The observed stable and processable porous structures have potential for broader applications, including oil/water/particle systems.