(256c) Impact of Size Disparity on Assemblies from Multi-Flavored Particles

Authors: 
Mao, R., Lehigh University
Pretti, E., Lehigh University
Mittal, J., Lehigh University
Binary superlattices constructed from colloidal particles have a wide variety of applications, including catalysis, molecular sensing, drug delivery, molecular and charge manipulation, and beyond. The recently proposed “multi-flavoring” technique for DNA-functionalized particles [1-3], wherein different complementary DNA strands are grafted to particles in varying amounts, can be used to independently adjust the relative interaction strength between different pairs of components in a binary mixture. In addition to the control of interactions, the size ratio between particles can also be adjusted, giving an additional degree of freedom for the assembled structures. In this work, we use molecular dynamics simulations to study a multi-flavored binary system of micron-sized DNA-functionalized particles modeled implicitly by Fermi–Jagla pairwise interactions. We show that a slight modification of the particle size ratio can improve the quality of the assembled structures. Further, the size disparity influences the contacting between different pairs, yielding the selection of rhombic-like to compositionally ordered to random-close-packed structures. Additionally, the crystal growth mechanism is investigated, of which a two-step transformation from amorphous aggregates to ordered crystals is observed.

Reference:

[1] Casey, M. T., Scarlett, R. T., Rogers, W. B., Jenkins, I., Sinno, T., & Crocker, J. C. (2012). Driving diffusionless transformations in colloidal crystals using DNA handshaking. Nature communications, 3, 1209.

[2] Song, M., Ding, Y., Zerze, H., Snyder, M. A., & Mittal, J. (2017). Binary superlattice design by controlling DNA-mediated interactions. Langmuir, 34(3), 991-998.

[3] Pretti, E., Zerze, H., Song, M., Ding, Y., Mahynski, N. A., Hatch, H. W., ... & Mittal, J. (2018). Assembly of three-dimensional binary superlattices from multi-flavored particles. Soft matter, 14(30), 6303-6312.