Anisotropic Self-Assembly from Isotropic Colloidal Building Blocks

Rey, Marcel; Law, Adam D.; Buzza, D. Martin A.; Vogel, Nicolas

Abstract

© 2017 American Chemical Society. Spherical colloidal particles generally self-assemble into hexagonal lattices in two dimensions. However, more complex, non-hexagonal phases have been predicted theoretically for isotropic particles with a soft repulsive shoulder but have not been experimentally realized. We study the phase behavior of microspheres in the presence of poly(N-isopropylacrylamide) (PNiPAm) microgels at the air/water interface. We observe a complex phase diagram, including phases with chain and square arrangements, which exclusively form in the presence of the microgels. Our experimental data suggests that the microgels form a corona around the microspheres and induce a soft repulsive shoulder that governs the self-assembly in this system. The observed structures are fully reproduced by both minimum energy calculations and finite temperature Monte Carlo simulations of hard core-soft shoulder particles with experimentally realistic interaction parameters. Our results demonstrate how complex, anisotropic assembly patterns can be realized from entirely isotropic building blocks by control of the interaction potential.

Citation

Rey, M., Law, A. D., Buzza, D. M. A., & Vogel, N. (2017). Anisotropic Self-Assembly from Isotropic Colloidal Building Blocks. Journal of the American Chemical Society, 139(48), 17464-17473. https://doi.org/10.1021/jacs.7b08503

• Journal Article Type: Article
• Acceptance Date: Oct 20, 2017
• Online Publication Date: Nov 14, 2017
• Publication Date: Dec 6, 2017
• Deposit Date: Dec 5, 2017
• Publicly Available Date: Nov 15, 2018
• Journal: Journal of the American Chemical Society
• Print ISSN: 0002-7863
• Electronic ISSN: 1520-5126
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 139
• Issue: 48
• Pages: 17464-17473
• DOI: https://doi.org/10.1021/jacs.7b08503
• Keywords: Colloid and surface chemistry; Biochemistry; General chemistry; Catalysis
• Public URL: https://hull-repository.worktribe.com/output/488678
• Publisher URL: http://pubs.acs.org/doi/abs/10.1021/jacs.7b08503