Preparation of a Yield Stress Pickering Emulsion Ink Stabilized by Naturally Occurring Bee Pollen Microparticles

Plant-based pollens have recently received significant attention in various fields owing to their numerous potential advantages including their unique architecture, mechanical strength, and high resistance to chemical attacks and biological degradation. In this study, we demonstrate viscoelastic Pickering emulsions of water and oil (trimethylolpropane trimethacrylate) stabilized by naturally occurring bee pollen microparticles. We systematically investigate the rheological properties of the pollen-stabilized emulsions with various pollen concentrations and water-to-oil ratios. It is observed that the emulsions prepared at a high pollen loading and an appropriate water-to-oil ratio show excellent shape retention and shear-thinning behaviors. The results suggest the possibility of utilizing pollen-stabilized Pickering emulsions for several applications including direct ink writing.