Patchy Particles   •    Particles at Interfaces   •    Field Assembly   •    Dye-sensitized Solar Cells   •    Electroactive Polymers   •    Swimmers   •    Metamaterials   •    Particle Films   •    Surface Modification   •    Three-dimensional Assembly   •    Particles as Templates

Fabrication of multi-patch particles

Patchy particles (i.e., particles with one or more patches that are less than 50% of the total particle surface) have attracted much attention due to its anisotropic surface property. The potential applications of such anisotropic particles lie in the fabrication of photonic crystals, targeted drug delivery, and electronics. And the unique assembly behavior has been investigated theoretically and experimental. The factors affecting the assembly results includes patch size, patch number per particle, patches’ relatives position and even patch shapes. The polymer chain, crystal lattice, directional assembly from patchy particles shows the huge potential of patchy particles’ capability in fabricating complex structures. To achieve all these application and assembly structures, many methods have been proposed to fabricate patchy particles.

Glancing Angle deposition (GLAD) is a method that have been widely reported and studied. Previously, a close-packed monolayer is needed to fabricate patchy particles in order to control the patch size. Here, we are trying to introduce a template in GLAD method, which can improve the uniformity of patches, and increasing the productivity (Figure 1 shows the schematic graph). And with the assistant of print technique and consequent application of GLAD method, more than one patch will be added to particles’ surface. With fine controlling the patch size and positions, the affect of patch number, size and position on the assembly behavior of multi-patch particles will be investigated. Figure 2 shows some samples of patch particles.

Figure 1. Schematic of template-assisted patchy particle fabrication using glancing angle deposition method with template at various angles. (A) I0 shows the metal vapor flow at an incident angle θ perpendicular to the grooves, I1 shows metal vapor flow at the same θ after rotation of the template by angle α. (B) Schematic showing metal vapor flows of two subsequent evaporations for the formation of multiple patches. I1 and I2 represent the directions of the two incident metal vapor flows at incident angles θ1 and θ2 after rotation of template by angles α1 and α2, respectively

Figure 2.Patches of different shapes achieved at different incident angles, θ and rotation angles, α.

Current Graduate Students: Zhenping He
Collaborators: Weikang Chen


Relevant Literature:
[1]He, Z.; Kretzschmar, I., Template-Assisted Fabrication of Patchy Particles with Uniform Patches. Langmuir 2012, 28, (26), 9915-9919.
[2]A. B. Pawar and Kretzschmar, I., Patchy Particles by Glancing Angle Deposition, Langmuir, 2008, 24 355-358.

• This work is supported by the Nanoscale Science Foundation under NSF Award Number CBET-PMP-1067501