(409h) Self-Assembly of Amphiphilic Janus Nanoparticles

Janus nanoparticles, due to their ability to self-assemble, have been of interest to researchers for over 30 years. Janus nanoparticles are defined by regions of differing properties on a nanoparticle surface. By changing the materials on the Janus nanoparticle surfaces, we can alter the characteristics of the self-assembled structures. In our research, we have modified nanoparticle surfaces with hydrophobic and hydrophilic compounds of varying molecular size to create amphiphilic Janus nanoparticles. Size ratio between the hydrophobic and hydrophilic molecules is altered between Janus nanoparticle samples to examine the difference in self-assembly behavior in selected solvents. To date, we have examined Janus nanoparticles composed of either iron oxide or silica cores. Hydrophilic compounds such as PEG (multiple Dalton weights) and fluorescent molecules have been utilized as well as various long chain hydrocarbons for the hydrophilic region. Using characterization methods including Dynamic Light Scattering, Fluorescent Spectroscopy, and Transmission Electron Microscope imaging, we are able to examine the surface of our Janus nanoparticles as well as self-assembled structures. By altering the size of the surface compounds as well as the size ratio of hydrophobic to hydrophilic compounds, we believe we can control the size of the self-assembled structures; this work provides a foundation for the development of self-assembled coatings composed of Janus nanoparticles, which have potential uses in improve water-resistant coatings and antimicrobial protective layers.