Molecular crystallization controlled by pH regulates mesoscopic membrane morphology

Cheuk Yui Leung, Liam C. Palmer, Bao Fu Qiao, Sumit Kewalramani, Rastko Sknepnek, Christina J. Newcomb, Megan A. Greenfield, Graziano Vernizzi, Samuel I Stupp, Michael J. Bedzyk, Monica Olvera De La Cruz

Research output: Contribution to journalArticle

42 Citations (Scopus)

Abstract

Coassembled molecular structures are known to exhibit a large variety of geometries and morphologies. A grand challenge of self-assembly design is to find techniques to control the crystal symmetries and overall morphologies of multicomponent systems. By mixing +3 and -1 ionic amphiphiles, we assemble crystalline ionic bilayers in a large variety of geometries that resemble polyhedral cellular crystalline shells and archaea wall envelopes. We combine TEM with SAXS and WAXS to characterize the coassembled structures from the mesoscopic to nanometer scale. The degree of ionization of the amphiphiles and their intermolecular electrostatic interactions are controlled by varying pH. At low and high pH values, we observe closed, faceted vesicles with two-dimensional hexagonal molecular arrangements, and at intermediate pH, we observe ribbons with rectangular-C packing. Furthermore, as pH increases, we observe interdigitation of the bilayer leaflets. Accurate atomistic molecular dynamics simulations explain the pH-dependent bilayer thickness changes and also reveal bilayers of hexagonally packed tails at low pH, where only a small fraction of anionic headgroups is charged. Coarse-grained simulations show that the mesoscale geometries at low pH are faceted vesicles where liquid-like edges separate flat crystalline domains. Our simulations indicate that the curved-to-polyhedral shape transition can be controlled by tuning the tail density in regions where sharp bends can form the polyhedral edges. In particular, the pH acts to control the overall morphology of the ionic bilayers by changing the local crystalline order of the amphiphile tails.

Original languageEnglish
Pages (from-to)10901-10909
Number of pages9
JournalACS Nano
Volume6
Issue number12
DOIs
Publication statusPublished - Dec 21 2012

Fingerprint

Crystallization
Amphiphiles
crystallization
Crystalline materials
membranes
Membranes
Geometry
Crystal symmetry
Coulomb interactions
Self assembly
Molecular structure
Ionization
Molecular dynamics
Tuning
geometry
Transmission electron microscopy
simulation
Computer simulation
Liquids
ribbons

Keywords

  • atomistic simulations
  • electrostatics
  • membrane morphology
  • pH
  • self-assembly
  • X-ray scattering

ASJC Scopus subject areas

  • Engineering(all)
  • Materials Science(all)
  • Physics and Astronomy(all)

Cite this

Leung, C. Y., Palmer, L. C., Qiao, B. F., Kewalramani, S., Sknepnek, R., Newcomb, C. J., ... Olvera De La Cruz, M. (2012). Molecular crystallization controlled by pH regulates mesoscopic membrane morphology. ACS Nano, 6(12), 10901-10909. https://doi.org/10.1021/nn304321w

Molecular crystallization controlled by pH regulates mesoscopic membrane morphology. / Leung, Cheuk Yui; Palmer, Liam C.; Qiao, Bao Fu; Kewalramani, Sumit; Sknepnek, Rastko; Newcomb, Christina J.; Greenfield, Megan A.; Vernizzi, Graziano; Stupp, Samuel I; Bedzyk, Michael J.; Olvera De La Cruz, Monica.

In: ACS Nano, Vol. 6, No. 12, 21.12.2012, p. 10901-10909.

Research output: Contribution to journalArticle

Leung, CY, Palmer, LC, Qiao, BF, Kewalramani, S, Sknepnek, R, Newcomb, CJ, Greenfield, MA, Vernizzi, G, Stupp, SI, Bedzyk, MJ & Olvera De La Cruz, M 2012, 'Molecular crystallization controlled by pH regulates mesoscopic membrane morphology', ACS Nano, vol. 6, no. 12, pp. 10901-10909. https://doi.org/10.1021/nn304321w
Leung CY, Palmer LC, Qiao BF, Kewalramani S, Sknepnek R, Newcomb CJ et al. Molecular crystallization controlled by pH regulates mesoscopic membrane morphology. ACS Nano. 2012 Dec 21;6(12):10901-10909. https://doi.org/10.1021/nn304321w
Leung, Cheuk Yui ; Palmer, Liam C. ; Qiao, Bao Fu ; Kewalramani, Sumit ; Sknepnek, Rastko ; Newcomb, Christina J. ; Greenfield, Megan A. ; Vernizzi, Graziano ; Stupp, Samuel I ; Bedzyk, Michael J. ; Olvera De La Cruz, Monica. / Molecular crystallization controlled by pH regulates mesoscopic membrane morphology. In: ACS Nano. 2012 ; Vol. 6, No. 12. pp. 10901-10909.
@article{01f675bb02334904ae0e516ec9ddb2dd,
title = "Molecular crystallization controlled by pH regulates mesoscopic membrane morphology",
abstract = "Coassembled molecular structures are known to exhibit a large variety of geometries and morphologies. A grand challenge of self-assembly design is to find techniques to control the crystal symmetries and overall morphologies of multicomponent systems. By mixing +3 and -1 ionic amphiphiles, we assemble crystalline ionic bilayers in a large variety of geometries that resemble polyhedral cellular crystalline shells and archaea wall envelopes. We combine TEM with SAXS and WAXS to characterize the coassembled structures from the mesoscopic to nanometer scale. The degree of ionization of the amphiphiles and their intermolecular electrostatic interactions are controlled by varying pH. At low and high pH values, we observe closed, faceted vesicles with two-dimensional hexagonal molecular arrangements, and at intermediate pH, we observe ribbons with rectangular-C packing. Furthermore, as pH increases, we observe interdigitation of the bilayer leaflets. Accurate atomistic molecular dynamics simulations explain the pH-dependent bilayer thickness changes and also reveal bilayers of hexagonally packed tails at low pH, where only a small fraction of anionic headgroups is charged. Coarse-grained simulations show that the mesoscale geometries at low pH are faceted vesicles where liquid-like edges separate flat crystalline domains. Our simulations indicate that the curved-to-polyhedral shape transition can be controlled by tuning the tail density in regions where sharp bends can form the polyhedral edges. In particular, the pH acts to control the overall morphology of the ionic bilayers by changing the local crystalline order of the amphiphile tails.",
keywords = "atomistic simulations, electrostatics, membrane morphology, pH, self-assembly, X-ray scattering",
author = "Leung, {Cheuk Yui} and Palmer, {Liam C.} and Qiao, {Bao Fu} and Sumit Kewalramani and Rastko Sknepnek and Newcomb, {Christina J.} and Greenfield, {Megan A.} and Graziano Vernizzi and Stupp, {Samuel I} and Bedzyk, {Michael J.} and {Olvera De La Cruz}, Monica",
year = "2012",
month = "12",
day = "21",
doi = "10.1021/nn304321w",
language = "English",
volume = "6",
pages = "10901--10909",
journal = "ACS Nano",
issn = "1936-0851",
publisher = "American Chemical Society",
number = "12",

}

TY - JOUR

T1 - Molecular crystallization controlled by pH regulates mesoscopic membrane morphology

AU - Leung, Cheuk Yui

AU - Palmer, Liam C.

AU - Qiao, Bao Fu

AU - Kewalramani, Sumit

AU - Sknepnek, Rastko

AU - Newcomb, Christina J.

AU - Greenfield, Megan A.

AU - Vernizzi, Graziano

AU - Stupp, Samuel I

AU - Bedzyk, Michael J.

AU - Olvera De La Cruz, Monica

PY - 2012/12/21

Y1 - 2012/12/21

N2 - Coassembled molecular structures are known to exhibit a large variety of geometries and morphologies. A grand challenge of self-assembly design is to find techniques to control the crystal symmetries and overall morphologies of multicomponent systems. By mixing +3 and -1 ionic amphiphiles, we assemble crystalline ionic bilayers in a large variety of geometries that resemble polyhedral cellular crystalline shells and archaea wall envelopes. We combine TEM with SAXS and WAXS to characterize the coassembled structures from the mesoscopic to nanometer scale. The degree of ionization of the amphiphiles and their intermolecular electrostatic interactions are controlled by varying pH. At low and high pH values, we observe closed, faceted vesicles with two-dimensional hexagonal molecular arrangements, and at intermediate pH, we observe ribbons with rectangular-C packing. Furthermore, as pH increases, we observe interdigitation of the bilayer leaflets. Accurate atomistic molecular dynamics simulations explain the pH-dependent bilayer thickness changes and also reveal bilayers of hexagonally packed tails at low pH, where only a small fraction of anionic headgroups is charged. Coarse-grained simulations show that the mesoscale geometries at low pH are faceted vesicles where liquid-like edges separate flat crystalline domains. Our simulations indicate that the curved-to-polyhedral shape transition can be controlled by tuning the tail density in regions where sharp bends can form the polyhedral edges. In particular, the pH acts to control the overall morphology of the ionic bilayers by changing the local crystalline order of the amphiphile tails.

AB - Coassembled molecular structures are known to exhibit a large variety of geometries and morphologies. A grand challenge of self-assembly design is to find techniques to control the crystal symmetries and overall morphologies of multicomponent systems. By mixing +3 and -1 ionic amphiphiles, we assemble crystalline ionic bilayers in a large variety of geometries that resemble polyhedral cellular crystalline shells and archaea wall envelopes. We combine TEM with SAXS and WAXS to characterize the coassembled structures from the mesoscopic to nanometer scale. The degree of ionization of the amphiphiles and their intermolecular electrostatic interactions are controlled by varying pH. At low and high pH values, we observe closed, faceted vesicles with two-dimensional hexagonal molecular arrangements, and at intermediate pH, we observe ribbons with rectangular-C packing. Furthermore, as pH increases, we observe interdigitation of the bilayer leaflets. Accurate atomistic molecular dynamics simulations explain the pH-dependent bilayer thickness changes and also reveal bilayers of hexagonally packed tails at low pH, where only a small fraction of anionic headgroups is charged. Coarse-grained simulations show that the mesoscale geometries at low pH are faceted vesicles where liquid-like edges separate flat crystalline domains. Our simulations indicate that the curved-to-polyhedral shape transition can be controlled by tuning the tail density in regions where sharp bends can form the polyhedral edges. In particular, the pH acts to control the overall morphology of the ionic bilayers by changing the local crystalline order of the amphiphile tails.

KW - atomistic simulations

KW - electrostatics

KW - membrane morphology

KW - pH

KW - self-assembly

KW - X-ray scattering

UR - http://www.scopus.com/inward/record.url?scp=84871551518&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84871551518&partnerID=8YFLogxK

U2 - 10.1021/nn304321w

DO - 10.1021/nn304321w

M3 - Article

C2 - 23185994

AN - SCOPUS:84871551518

VL - 6

SP - 10901

EP - 10909

JO - ACS Nano

JF - ACS Nano

SN - 1936-0851

IS - 12

ER -