Issue 24, 2010

Anomalous phase behavior of liquid–vapor phase transition in binary mixtures of DNA-coated particles

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.

Graphical abstract: Anomalous phase behavior of liquid–vapor phase transition in binary mixtures of DNA-coated particles

Article information

Article type
Paper
Submitted
23 Jun 2010
Accepted
21 Sep 2010
First published
07 Oct 2010

Soft Matter, 2010,6, 6136-6145

Anomalous phase behavior of liquid–vapor phase transition in binary mixtures of DNA-coated particles

F. J. Martinez-Veracoechea, B. Bozorgui and D. Frenkel, Soft Matter, 2010, 6, 6136 DOI: 10.1039/C0SM00567C

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements