Photoisomerization induced scission of rod-like micelles unravelled with multiscale modeling

G. Heerdt, I. Tranca, A.J. Markvoort, B.M. Szyja, N.H. Morgon, E.J.M. Hensen

Research output: Contribution to journalArticleAcademicpeer-review

3 Downloads (Pure)

Abstract

Hypothesis In photorheological fluids, subtle molecular changes caused by light lead to abrupt macroscopic alterations. Upon UV irradiation of an aqueous cetyltrimethylammonium bromide (CTAB) and trans-ortho-methoxycinnamic acid (trans-OMCA) solution, for instance, the viscosity drops over orders of magnitude. Multiscale modeling allows to elucidate the mechanisms behind these photorheological effects. Experiments We use time-dependent DFT calculations to study the photoisomerization, and a combination of atomistic molecular dynamics (MD) and DFT to probe the influence of both OMCA isomers on the micellar solutions. Findings The time-dependent DFT calculations show that the isomerization pathway occurs in the first triplet excited state with a minimum energy conformation closest to the after photoisomerization predominant cis configuration. In the MD simulations, with sub-microsecond timescales much shorter than the experimental morphological transition, already a clear difference is observed in the packing of the two OMCA isomers: contrary to trans-OMCA, cis-OMCA exposes notable part of its hydrophobic aromatic rings at the micelle surface. This can explain why trans-OMCA adopts rod-like micellar packing (high viscosity) while cis-OMCA spherical micellar packing (low viscosity). Moreover, lowering of the OMCA co-solute concentration allowed us to perform full simulation of the breakup process of the rod-like micelles which are stable prior to isomerization.

Original languageEnglish
Pages (from-to)357-367
Number of pages11
JournalJournal of Colloid and Interface Science
Volume510
DOIs
Publication statusPublished - 15 Jan 2018

Fingerprint

Photoisomerization
Micelles
Discrete Fourier transforms
NSC 153174
Viscosity
Isomerization
Isomers
Acids
Molecular dynamics
Excited states
Conformations
Irradiation
Fluids
Computer simulation
Experiments

Keywords

  • MD simulations
  • Micelle transition
  • Photorheology
  • Rotational barriers
  • Time-dependent DFT

Cite this

@article{24b5a630ddef4be39a3e810e838b5dc6,
title = "Photoisomerization induced scission of rod-like micelles unravelled with multiscale modeling",
abstract = "Hypothesis In photorheological fluids, subtle molecular changes caused by light lead to abrupt macroscopic alterations. Upon UV irradiation of an aqueous cetyltrimethylammonium bromide (CTAB) and trans-ortho-methoxycinnamic acid (trans-OMCA) solution, for instance, the viscosity drops over orders of magnitude. Multiscale modeling allows to elucidate the mechanisms behind these photorheological effects. Experiments We use time-dependent DFT calculations to study the photoisomerization, and a combination of atomistic molecular dynamics (MD) and DFT to probe the influence of both OMCA isomers on the micellar solutions. Findings The time-dependent DFT calculations show that the isomerization pathway occurs in the first triplet excited state with a minimum energy conformation closest to the after photoisomerization predominant cis configuration. In the MD simulations, with sub-microsecond timescales much shorter than the experimental morphological transition, already a clear difference is observed in the packing of the two OMCA isomers: contrary to trans-OMCA, cis-OMCA exposes notable part of its hydrophobic aromatic rings at the micelle surface. This can explain why trans-OMCA adopts rod-like micellar packing (high viscosity) while cis-OMCA spherical micellar packing (low viscosity). Moreover, lowering of the OMCA co-solute concentration allowed us to perform full simulation of the breakup process of the rod-like micelles which are stable prior to isomerization.",
keywords = "MD simulations, Micelle transition, Photorheology, Rotational barriers, Time-dependent DFT",
author = "G. Heerdt and I. Tranca and A.J. Markvoort and B.M. Szyja and N.H. Morgon and E.J.M. Hensen",
year = "2018",
month = "1",
day = "15",
doi = "10.1016/j.jcis.2017.09.036",
language = "English",
volume = "510",
pages = "357--367",
journal = "Journal of Colloid and Interface Science",
issn = "0021-9797",
publisher = "Academic Press Inc.",

}

Photoisomerization induced scission of rod-like micelles unravelled with multiscale modeling. / Heerdt, G.; Tranca, I.; Markvoort, A.J.; Szyja, B.M.; Morgon, N.H.; Hensen, E.J.M.

In: Journal of Colloid and Interface Science, Vol. 510, 15.01.2018, p. 357-367.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Photoisomerization induced scission of rod-like micelles unravelled with multiscale modeling

AU - Heerdt, G.

AU - Tranca, I.

AU - Markvoort, A.J.

AU - Szyja, B.M.

AU - Morgon, N.H.

AU - Hensen, E.J.M.

PY - 2018/1/15

Y1 - 2018/1/15

N2 - Hypothesis In photorheological fluids, subtle molecular changes caused by light lead to abrupt macroscopic alterations. Upon UV irradiation of an aqueous cetyltrimethylammonium bromide (CTAB) and trans-ortho-methoxycinnamic acid (trans-OMCA) solution, for instance, the viscosity drops over orders of magnitude. Multiscale modeling allows to elucidate the mechanisms behind these photorheological effects. Experiments We use time-dependent DFT calculations to study the photoisomerization, and a combination of atomistic molecular dynamics (MD) and DFT to probe the influence of both OMCA isomers on the micellar solutions. Findings The time-dependent DFT calculations show that the isomerization pathway occurs in the first triplet excited state with a minimum energy conformation closest to the after photoisomerization predominant cis configuration. In the MD simulations, with sub-microsecond timescales much shorter than the experimental morphological transition, already a clear difference is observed in the packing of the two OMCA isomers: contrary to trans-OMCA, cis-OMCA exposes notable part of its hydrophobic aromatic rings at the micelle surface. This can explain why trans-OMCA adopts rod-like micellar packing (high viscosity) while cis-OMCA spherical micellar packing (low viscosity). Moreover, lowering of the OMCA co-solute concentration allowed us to perform full simulation of the breakup process of the rod-like micelles which are stable prior to isomerization.

AB - Hypothesis In photorheological fluids, subtle molecular changes caused by light lead to abrupt macroscopic alterations. Upon UV irradiation of an aqueous cetyltrimethylammonium bromide (CTAB) and trans-ortho-methoxycinnamic acid (trans-OMCA) solution, for instance, the viscosity drops over orders of magnitude. Multiscale modeling allows to elucidate the mechanisms behind these photorheological effects. Experiments We use time-dependent DFT calculations to study the photoisomerization, and a combination of atomistic molecular dynamics (MD) and DFT to probe the influence of both OMCA isomers on the micellar solutions. Findings The time-dependent DFT calculations show that the isomerization pathway occurs in the first triplet excited state with a minimum energy conformation closest to the after photoisomerization predominant cis configuration. In the MD simulations, with sub-microsecond timescales much shorter than the experimental morphological transition, already a clear difference is observed in the packing of the two OMCA isomers: contrary to trans-OMCA, cis-OMCA exposes notable part of its hydrophobic aromatic rings at the micelle surface. This can explain why trans-OMCA adopts rod-like micellar packing (high viscosity) while cis-OMCA spherical micellar packing (low viscosity). Moreover, lowering of the OMCA co-solute concentration allowed us to perform full simulation of the breakup process of the rod-like micelles which are stable prior to isomerization.

KW - MD simulations

KW - Micelle transition

KW - Photorheology

KW - Rotational barriers

KW - Time-dependent DFT

UR - http://www.scopus.com/inward/record.url?scp=85029828738&partnerID=8YFLogxK

U2 - 10.1016/j.jcis.2017.09.036

DO - 10.1016/j.jcis.2017.09.036

M3 - Article

C2 - 28961434

AN - SCOPUS:85029828738

VL - 510

SP - 357

EP - 367

JO - Journal of Colloid and Interface Science

JF - Journal of Colloid and Interface Science

SN - 0021-9797

ER -