Anomalous phase behavior of liquid–vapor phase transition in binary mixtures of DNA-coated particles
- 1 January 2010
- journal article
- Published by Royal Society of Chemistry (RSC) in Soft Matter
- Vol. 6 (24), 6136-6145
- https://doi.org/10.1039/c0sm00567c
Abstract
We report a Monte Carlo study of a 1:1 binary mixture of particles coated with DNA chains with “sticky” ends. The system was modeled using a coarse-grained representation. In order to map out the phase diagram of this model system we combined biased Monte Carlo simulations with histogram reweighting techniques. We find that, at low temperatures (strong hybridization) this system undergoes a phase separation between a dilute vapor-like phase and a dense network-forming liquid-like phase. We observe a surprising non-monotonic dependence of the coexistence pressure on the temperature, or more precisely, on the reduced hybridization free energy (fhyb/kBT). This anomalous behavior can be understood in terms of a cross-over between two distinct regimes for the driving force of the phase transition: a hybridization-free-energy-driven regime and an entropy-driven regime. In the former regime, we observe a “normal” vapor–liquid equilibrium where during condensation, the system gains hybridization free energy but loses entropy. In the entropy-driven regime, the phase transition is driven by the increase in entropy due to the re-arrangement of sticky-end bonds in the liquid phase. Finally, we observe that the system can only undergo phase separation if the valence (i.e., the number of DNA-chains per particle) is larger than two. The coexistence region widens markedly as the valence is increased.Keywords
This publication has 62 references indexed in Scilit:
- Assembly and organization processes in DNA-directed colloidal crystallizationProceedings of the National Academy of Sciences, 2009
- Curvature-Induced Base Pair “Slipping” Effects in DNA-Nanoparticle HybridizationNano Letters, 2009
- DNA-guided crystallization of colloidal nanoparticlesNature, 2008
- DNA-programmable nanoparticle crystallizationNature, 2008
- A finite-cluster phase in λ-DNA-coated colloidsSoft Matter, 2007
- Engineering DNA-Mediated Colloidal CrystallizationLangmuir, 2006
- Optimizing the ensemble for equilibration in broad-histogram Monte Carlo simulationsPhysical Review E, 2004
- DNA-Directed Synthesis of Binary Nanoparticle Network MaterialsJournal of the American Chemical Society, 1998
- Organization of 'nanocrystal molecules' using DNANature, 1996
- A DNA-based method for rationally assembling nanoparticles into macroscopic materialsNature, 1996