Journal
JOURNAL OF PHYSICAL CHEMISTRY B
Volume 120, Issue 34, Pages 9152-9160Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acs.jpcb.6b04717
Keywords
-
Categories
Funding
- CNR (National Research Council, Italy)
- CAS (Chinese Academy of Sciences, China) through a CNR-CAS
- CINECA (ISCRA project) [HP10BZQZGE]
- MIUR (PRIN HI-PHUTURE) [2010N3T9M4_001]
- MIUR (FIRB) [RBAP11C58Y_003]
- Fondazione CARIPARO
- National Natural Science Foundation of China [11274319, 11421063]
Ask authors/readers for more resources
In order to investigate the role of the electrostatic interactions in stabilizing various phases of ionic liquids, especially smectic ionic liquid crystals, we have employed a coarse-grained model of 1-hexadecyl-3-methylimidazolium nitrate, [C(16)mim][NO3], to perform molecular dynamics simulations with the partial charges artificially rescaled by a factor from 0.7 to 1.2. The simulated systems have been characterized by means of orientational and translational order parameters and by distribution functions. We have found that increasing the total charge of the ions strongly stabilizes the ionic smectic phase by shifting the clearing point (melting into the isotropic liquid phase) to higher temperatures, while a smaller effect is observed on the stability of the crystal phase. Our results highlight the importance of the electrostatic interactions in promoting the formation of ionic liquid crystals through microphase segregation. Moreover, as the total charge of the model is increased, we observe a transformation from a homogeneous to a nanosegregated isotropic structure typical of ionic liquids. Therefore, a connection can be established between the degree of nanosegregation of ILs and the stability of ILC phases. All the above can be understood by the competition among electrostatic interactions between charged groups (cationic head groups and anions), van der Waals interactions between nonpolar cationic tail groups, and thermal fluctuations.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available