Particles with tunable porosity and morphology by controlling interfacial instability in block copolymer emulsions

Abstract

A series of porous block copolymer (BCP)
particles with controllable morphology and pore sizes was
fabricated by tuning the interfacial behavior of BCP droplets
in oil-in-water emulsions. A synergistic adsorption of
polystyrene-b-poly(4-vinylpyridine) (PS-b-P4VP) BCPs
and sodium dodecyl sulfate (SDS) to the surface of the
emulsion droplet induced a dramatic decrease in the
interfacial tension and generated interfacial instability at
the particle surface. In particular, the SDS concentration
and the P4VP volume fraction of PS-b-P4VP were key
parameters in determining the degree of interfacial
instability, leading to different types of particles including micelles, capsules, closed-porosity particles, and open-porosity particles with tunable pore sizes ranging from 10 to 500 nm. The particles with open-porosity could be used as pH- responsive, high capacity delivery systems where the uptake and release of multiple dyes could be achieved.