Pickering Emulsion Templated Layer-by-Layer Assembly for Making Microcapsules

Pickering emulsions stabilized by poly(sodium styrenesulfonate) (PSS) surface-modified LUDOX CL particles were used as templates for the layer-by-layer (LbL) deposition of polyelectrolytes and charged nanoparticles to form composite shells. The microcapsules resulting from repeated LbL coating with poly(diallyldimethylammonium chloride) (PDADMAC) and PSS had porous walls due to the loose arrangement of the original nanoparticle aggregates at the oil-water interface, leading to significant microcapsule rupture and low encapsulation efficiency. Microcapsules formed by coating with PDADMAC and anionic LUDOX HS nanoparticles led to dense walls and stronger microcapsules, suitable for microencapsulation of hydrophobic materials with a wide range of polarities.