Plasma and Fusion Research

Volume 6, 2401040 (2011)

Regular Articles

Molecular Dynamics Simulation of Micellar Shape Change in Amphiphilic Solution
Susumu FUJIWARA, Takashi ITOH, Masato HASHIMOTO, Yuichi TAMURA1), Hiroaki NAKAMURA2) and Ritoku HORIUCHI2)
Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
1)
Konan University, 8-9-1 Okamoto, Higashinada-ku, Kobe 658-8501, Japan
2)
National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
(Received 7 December 2010 / Accepted 7 March 2011 / Published 1 July 2011)

Abstract

Micellar shape change in an amphiphilic solution is investigated by a molecular dynamics simulation of coarse-grained semiflexible amphiphilic molecules with explicit solvent molecules. Our simulations show that a cylindrical micelle is obtained at small molecular rigidity while a disc-shaped micelle appears at large molecular rigidity. We find that most chains are in an extended conformation at large molecular rigidity whereas the fraction of the chains in a bent conformation becomes large at small molecular rigidity. It is also ascertained that the micellar shape starts to change immediately after sudden increase of the molecular rigidity while an induction time is needed to change the micellar shape after sudden decrease of the molecular rigidity. This result can be qualitatively explained by considering the bond-bending potential energy and the conformational entropy of the amphiphilic molecules.

Keywords

molecular dynamics simulation, molecular rigidity, micellar shape change, chain conformation, amphiphilic solution

DOI: 10.1585/pfr.6.2401040

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This paper may be cited as follows:

Susumu FUJIWARA, Takashi ITOH, Masato HASHIMOTO, Yuichi TAMURA, Hiroaki NAKAMURA and Ritoku HORIUCHI, Plasma Fusion Res. 6, 2401040 (2011).