Abstract
The structure of the tilted phase of monolayer-protected nanoparticles is investigated by means of a simple Ginzburg-Landau model. The theory contains two dimensionless parameters representing the preferential tilt angle and the ratio ε between the energy cost due to spatial variations in the tilt of the coating molecules and that of the van der Waals interactions which favors the preferential tilt. We analyze the model for both spherical and octahedral particles. On spherical particles, we find a transition from a tilted phase, at small ε, to a phase where the molecules spontaneously align along the surface normal and tilt disappears. Octahedral particles have an additional phase at small ε characterized by the presence of six topological defects. These defective configurations provide preferred sites for the chemical functionalization of monolayer-protected nanoparticles via place-exchange reactions and their consequent linking to form molecules and bulk materials. Copyright © EPLA, 2012.
Original language | English (US) |
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Pages (from-to) | 36005 |
Journal | EPL (Europhysics Letters) |
Volume | 97 |
Issue number | 3 |
DOIs | |
State | Published - Feb 6 2012 |
Externally published | Yes |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-01Acknowledged KAUST grant number(s): KUK-C1-013-04
Acknowledgements: LG and MJB would like to thank F. STELLACCI for the insightful conversations that inspired this work. MJB thanks T. ASEFA for enlightening discussions of the chemistry of SAMs. We gratefully acknowledge support from the Wyss Institute (LG), the Harvard Kavli Institue for Bionano Science & Technology (LG), the NSF Harvard MRSEC (LG). The work of MJB and XM was supported by the National Science Foundation grant DMR-0808812. AM is supported by Award No. KUK-C1-013-04, made by King Abdullah University of Science and Technology (KAUST), to the Oxford Centre for Collaborative Applied Mathematics and an EPSRC Career Acceleration Fellowship EP/J001686/1.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.