| Full text | |
| Author(s): |
Heerdt, Gabriel
[1]
;
Tranca, Ionut
[2]
;
Markvoort, Albert J.
[3, 4]
;
Szyja, Bartlomiej M.
[5]
;
Morgon, Nelson H.
[1]
;
Hensen, Emiel J. M.
[2]
Total Authors: 6
|
| Affiliation: | [1] Univ Estadual Campinas, Dept Phys Chem, Inst Chem, POB 6154, BR-13083970 Campinas, SP - Brazil
[2] Eindhoven Univ Technol, Lab Inorgan Mat Chem, Dept Chem Engn & Chem, POB 513, NL-5600 MB Eindhoven - Netherlands
[3] Eindhoven Univ Technol, Computat Biol Grp, Dept Biomed Engn, POB 513, NL-5600 MB Eindhoven - Netherlands
[4] Eindhoven Univ Technol, Inst Complex Mol Syst, POB 513, NL-5600 MB Eindhoven - Netherlands
[5] Wroclaw Univ Sci & Technol, Div Fuels Chem & Technol, Fac Chem, Gdanska 7-9, PL-50344 Wroclaw - Poland
Total Affiliations: 5
|
| Document type: | Journal article |
| Source: | Journal of Colloid and Interface Science; v. 510, p. 357-367, JAN 15 2018. |
| Web of Science Citations: | 0 |
| 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. (C) 2017 Elsevier Inc. All rights reserved. (AU) | |
| FAPESP's process: | 16/04963-6 - Molecular dynamics of cellulose enzymatic hydrolysis and QM / MM simulations of chemical reactions in biomolecular systems |
| Grantee: | Gabriel Heerdt |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |