(488b) Bio-Inspired Magnetic Pollen Particles Tailored with Adherents for Tuning Adhesion Strength and Optical Properties

Authors: 
Lin, H., Georgia Institute of Technology
Meredith, J. C., Georgia Institute of Technology
Wu, J., Georgia Institute of Technology
Shin, D., Georgia Institute of Technology

Nature provides remarkable examples of bio-microscale particles with well-optimized structures and/or chemistries for the design of novel functional materials with effective adhesion to a variety of porous or dense surfaces. Herein, we reported the development of bio-inspired magnetic pollen grains as novel multifunctional microparticles with tailored specificity in both adherence and optical activity. The adhesion strength of as-synthesized magnetic pollen grain is significantly enhanced through the synergic interactions of the short-range van der Waals (VDW) force//hydrogen bonding, the long-range magnetic force and capillary force into one particle. The long-range magnetic force is dependent on the amount of Fe3O4 particles loading in the core, while the VDW force and the capillary interaction are tuned through coating polystyrene (PS) nanoparticle, chitin nanofiber and a layer of viscous pollenkitt on the shell surface, respectively. For optical activity, the as-synthesized magnetic pollen grains exhibit varied light-reflective intensities with different surface modifications. The difference of reflective indices of surface coating materials determined the pollen grain light-reflective properties, which were enhanced with pollenkitt coating, and dramatically reduced with PS nano-particle coatings. This present strategy provides us with new insight on the exploring of the generation of multifunctional particles with significantly-enhanced taggants capabilities, and it could further extend to other pollen grains and their biomimetic-replica high-aspect-ratio particles with numerous different nanoscale surface features for adhesion purpose.