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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Modulation of Turing Patterns in the CDIMA Reaction by Ultraviolet and Visible Light

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Nagao, Raphael [1, 2] ; de Miranda, Renan C. C. [1] ; Epstein, Irving R. [3, 4] ; Dolnik, Milos [3, 4]
Total Authors: 4
[1] Univ Estadual Campinas, Inst Chem, BR-13083970 Campinas, SP - Brazil
[2] Univ Estadual Campinas, Ctr Innovat New Energies, BR-13083841 Campinas, SP - Brazil
[3] Brandeis Univ, Dept Chem, Waltham, MA 02454 - USA
[4] Brandeis Univ, Volen Ctr Complex Syst, Waltham, MA 02454 - USA
Total Affiliations: 4
Document type: Journal article
Source: Journal of Physical Chemistry A; v. 123, n. 5, p. 992-998, FEB 7 2019.
Web of Science Citations: 0

We have carried out the first systematic study of the effects of ultraviolet light, both alone and in combination with visible white light, on Turing patterns in the chlorine dioxide-iodine-malonic acid (CDIMA) reaction. The ultraviolet light used has a sharp peak at 368 nm and can perturb the system selectively. It primarily decomposes chlorine dioxide in a zeroth-order reaction, and when it is used to illuminate Turing patterns, shrunken spots are formed with an imperfect hexagonal arrangement. The ultraviolet light competes directly with the visible white light via the photoreaction with dissolved chlorine dioxide, which prevents the total suppression of patterns at intermediate intensities of white light. These results suggest that specific wavelengths of light in the ultraviolet spectrum selectively modify the chemistry behind the pattern formation and can be utilized to generate novel self-organized structures under forcing conditions. We propose a modified Lengyel-Epstein model to incorporate the effect of ultraviolet illumination and obtain good qualitative agreement between simulations and experiments. These results support the idea that chlorine dioxide photoreaction is a key step in modulating CDIMA patterns under ultraviolet illumination. (AU)

FAPESP's process: 16/22262-5 - Design and control of self-organized electrochemical patterns
Grantee:Raphael Nagao de Sousa
Support type: Scholarships in Brazil - Young Researchers
FAPESP's process: 16/01817-9 - Design and control of self-organized electrochemical patterns
Grantee:Raphael Nagao de Sousa
Support type: Research Grants - Young Investigators Grants