(463d) Single Magnet Directed Synchronization of Magnetic Janus Particles

Authors: 
Hwang, S., University of Michigan
Bhaskar, S., University of Michigan
Lahann, J., University of Michigan
Yoon, J., University of Michigan


We, herein, introduce preparations of various types of magnetic Janus particles (MJPs) with different sizes and chemical components by means of the electrohydrodynamic (EHD) co-jetting, which has been recently known for producing multi-compartmentalized particles.  Two distinctive polymers, a water soluble poly(acrylamide-co-acrylic acid) (p(AAM-co-AA) and an organic solvent soluble poly(lactic-co-glycolic acid) (PLGA), were respectively used to prepare MJPs. The controlled diameters of MJPs were obtained from submicron to tens of micron in this study. Along with the magnetite compartment having the superparamagnetic property in the MJPs, two different pigments/fluorescence dyes including carbon black (CB) and titanium dioxide (TiO2), and various fluorescence polymers were also compartmentalized by designed manners in the process of EHD co-jetting, which can be used as secondary functional materials such as demonstrating different optical/fluorescent colors.

Magnetic responses of MJPs toward various orientations and rotations of a given magnetic field are clearly described in this work. Magnetic anisotropy in MJPs that is originated from the shape anisotropy plays a key role in those magnetic responses. Based on those studies, we found a new methodology to ensemble colloidal behaviors of MJPs, which can effectively express the secondary functions embedded in the anisotropic particles. Detailed experimental conditions for such synchronization of MJPs’ dynamics via a single magnet are also presented.