skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Low-symmetry sphere packings of simple surfactant micelles induced by ionic sphericity

Authors:
; ; ORCiD logo; ORCiD logo
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
DOE - BASIC ENERGY SCIENCES
OSTI Identifier:
1368281
Resource Type:
Journal Article
Resource Relation:
Journal Name: Proceedings of the National Academy of Sciences of the United States of America; Journal Volume: 114; Journal Issue: 16
Country of Publication:
United States
Language:
ENGLISH

Citation Formats

Kim, Sung A., Jeong, Kyeong-Jun, Yethiraj, Arun, and Mahanthappa, Mahesh K. Low-symmetry sphere packings of simple surfactant micelles induced by ionic sphericity. United States: N. p., 2017. Web. doi:10.1073/pnas.1701608114.
Kim, Sung A., Jeong, Kyeong-Jun, Yethiraj, Arun, & Mahanthappa, Mahesh K. Low-symmetry sphere packings of simple surfactant micelles induced by ionic sphericity. United States. doi:10.1073/pnas.1701608114.
Kim, Sung A., Jeong, Kyeong-Jun, Yethiraj, Arun, and Mahanthappa, Mahesh K. Mon . "Low-symmetry sphere packings of simple surfactant micelles induced by ionic sphericity". United States. doi:10.1073/pnas.1701608114.
@article{osti_1368281,
title = {Low-symmetry sphere packings of simple surfactant micelles induced by ionic sphericity},
author = {Kim, Sung A. and Jeong, Kyeong-Jun and Yethiraj, Arun and Mahanthappa, Mahesh K.},
abstractNote = {},
doi = {10.1073/pnas.1701608114},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
number = 16,
volume = 114,
place = {United States},
year = {Mon Apr 03 00:00:00 EDT 2017},
month = {Mon Apr 03 00:00:00 EDT 2017}
}
  • We report the discovery of an ionic small molecule surfactant that undergoes water-drive self- assembly into quasispherical micelles, which pack into the first lyotropic liquid crystalline Frank–Kasper σ phase. Small-angle X-ray scattering studies indicate that this unexpected, low-symmetry phase is characterized by a tetragonal unit cell, in which 30 sub-2 nm micelles of five discrete types are arranged into a tetrahedral close packing with exceptional translational order. Varying the relative amounts of surfactant and water in these lyotropic phases enables formation of a Frank–Kasper A15 sphere packing and a more common body-centered cubic structure. MD simulations reveal that the symmetrymore » breaking that drives the selection of the σ and A15 phases arises from a delicate interplay between the drive to maintain local spherical particle symmetry and the maximization of electrostatic cohesion between the soft micellar particles.« less
    Cited by 5
  • We report the discovery of an ionic small molecule surfactant that undergoes water-drive self- assembly into quasispherical micelles, which pack into the first lyotropic liquid crystalline Frank–Kasper σ phase. Small-angle X-ray scattering studies indicate that this unexpected, low-symmetry phase is characterized by a tetragonal unit cell, in which 30 sub-2 nm micelles of five discrete types are arranged into a tetrahedral close packing with exceptional translational order. Varying the relative amounts of surfactant and water in these lyotropic phases enables formation of a Frank–Kasper A15 sphere packing and a more common body-centered cubic structure. MD simulations reveal that the symmetrymore » breaking that drives the selection of the σ and A15 phases arises from a delicate interplay between the drive to maintain local spherical particle symmetry and the maximization of electrostatic cohesion between the soft micellar particles.« less
  • In some recent studies Vikingstad has pointed out that when water-soluble alcohols are dissolved in aqueous micellar solutions, most of the alcohol molecules are solubilized in the micelles, thereby decreasing the aggregation number. A literature study has been made on the effect of different n-alcohols on either the average micellar molar mass, M, or the average aggregation number, N. The conclusion is that addition of small amounts of alcohol may increase the aggregation number. Larger amounts of water-soluble alcohols (methanol, propanol) seem to decrease N, while sparingly soluble alcohols (octanol, dodecanol) seem to increase N. With very large amounts ofmore » water-soluble alcohols there is no evidence of micelle formation.« less
  • Rate constants have been determined for the hydrolysis of 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) as functions of hydroxide ion concentrations in water, micellar hexadecyltrimethylammonium bromide (CTAB), and dioctacecyldimethylammonium chloride (DODAC) surfactant vesicles. The observed second-order rate constants at 26.4 C in micellar CTAB (8.4 m/sup -1/ sec/sup -1/) are /Ca. 15- and 1500-fold larger than that in water (0.54 m/sup -1/ sec/sup -1/). The rate-concentration profiles in both surfactant systems fit the pseudophase-type models of micellar catalysis. Kinetic treatments derived from micellar catalysis also are applicable to surfactant vesicles. 88 references.
  • Quasi-elastic light scattering measurements have been performed on aqueous solutions of CTAB (cetyltrimethylammonium bromide). Theoretic fits to the measured diffusion coefficients at low NaBr were obtained by using the generalized Stokes-Einstein equation expanded to first order in the surfactant concentration (including both thermodynamic and hydrodynamic terms), with a pair-interaction potential taken from Dlvo theory. Good fits are obtained at low NaBr concentrations by assuming a constant micellar radius for each temperature and assuming that the remaining parameters (aggregation number, fractional ionization, and Hamaker coefficient) are independent of temperature. This procedure yields an unambiguous value for the fractional ionization alpha formore » CTAB micelles: alpha = 0.22. The limits of validity of the theoretic fitting procedure (previously applied by Corti and Degiorgio to the system sodium n-dodecyl sulfate (SDS) + NaCl) are discussed. 65 references.« less