Research
Patchy Particles • Particles at Interfaces • Field Assembly • Dye-sensitized Solar Cells • Electroactive Polymers • Swimmers • Metamaterials • Particle Films • Surface Modification • Three-dimensional Assembly • Particles as TemplatesThree-dimensional Assembly
Currently, research in this area is theoretical in nature. Using a two-dimensional Ising lattice density functional model originally developed by Aranovich and Donohue,[1] we are predicting regions in the phase diagram where pre-designed particle structures are stable. We are specifically looking for:
• relative particle concentrations,
• patch-patch and unmodified surfaces-patch binding interactions, and
• suitable temperature range.
We are particular interested in the T structures depicted in Figures 1 and 2. The T structure serves as an interesting model structure for plasmonic waveguides, three-way interconnects, three-way connectors, spin filters, or a transistor structure with leads, where the center particle has the properties of a transistor.
The T structure consists of one three-patch particle (A), three two-patch particles (Bn, n = 1,2), and three one-patch particles C. The T structure can be assembled using a symmetric two-patch particle, B1, (Fig. 1) or an asymmetric two-patch particle, B2, (Fig. 2).
Parameters leading to the formation of the T structure at 300 K are found for both sets of particles, B1 and B2, and their respective interactions. The effect of particle concentration and particle interaction energies on the assembly of the T structure has been elucidated. Our calculations show that the careful choice of particle patch interactions reduces the amount of additional structures accessible (i.e., system with B1 particle), but also results in a more challenging synthetic route involving asymmetric molecular linkers. Further studies of the effect of dynamics on the assembly are in progress.
Students:
Current Graduate Student:
Current Undergraduate Student:
Former Contributors:Amar B. Pawar, Kevin Wallenstein
Relevant Literature:
[1]“Modeling self-assembly in molecular fluids” G. L. Aranovich, M. D. Donohue J. Chem. Phys., 2002, 116, 7255-7268.
[2]“Self-assembly of T Structures in Molecular Fluids” A. B. Pawar, I. Kretzschmar*, G. L. Aranovich, M. D. Donohue J. Phys. Chem., 2007, ASAP Article, DOI: 10.1021/jp0646372. PDF
Funding:
• CCNY and CUNY start-up funds