Title
Controlled Aggregation and Enhanced Two-Photon Absorption of a Water-Soluble Squaraine Dye with a Poly(acrylic acid) Template
Abbreviated Journal Title
Langmuir
Keywords
LANGMUIR-BLODGETT-FILMS; ANIONIC POLYELECTROLYTES; SURFACTANT; SQUARAINES; MOLECULAR-STRUCTURE; SQUARIC ACID; CA2+ IONS; DYNAMICS; FLUORESCENCE; BEHAVIOR; BINDING; Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, ; Multidisciplinary
Abstract
Controlling the aggregation behavior of organic dyes is important for understanding and exploring supramolecular assembly utilizing the specific characteristics of aggregation. Regulating J-aggregation by electrostatic interactions between anionic polyelectrolytes and cationic dyes has gained growing interest. Here, we report the formation of J-aggregates of a water-soluble cationic squaraine dye, 4(pyridinium-1-yl)butylbenzothiazolium squaraine (SQ), using poly(acrylic acid) sodium salt (PAA-Na) as a template. Electrostatic interactions between the PAA-Na polyelectrolyte and the cationic SQ dye enhanced J-aggregation; the absorbance. of the resulting J-band with the polyelectrolyte template was much sharper than the absorbance of the J-aggregate formed using a high concentration of NaCl. Significantly, removal of the polyelectrolyte PPA-Na template by the introduction of calcium ions, which can form stronger ionic binding with carboxylate groups, dissociated J-aggregates, freeing the SQ molecules back to unaggregated or lower aggregate forms. To demonstrate the reversibility of the J-aggregate formation cycle, an in situ experiment was conducted that showed 60% reversibility of the second cycle. In addition, an enhancement by ca. 23 times per repeat unit of the two-photon absorption (2PA) cross section was observed at 920 nm for the polyelectrolyte template-SQ J-aggregate compared to unaggregated or lower aggregate SQ These results suggest a prominent role of polyelectrolyte templated SQ J, aggregation in the enhancement of 2PA efficiency and provide a means of modulating supramolecular assembly.
Journal Title
Langmuir
Volume
29
Issue/Number
35
Publication Date
1-1-2013
Document Type
Article
DOI Link
Language
English
First Page
11005
Last Page
11012
WOS Identifier
ISSN
0743-7463
Recommended Citation
"Controlled Aggregation and Enhanced Two-Photon Absorption of a Water-Soluble Squaraine Dye with a Poly(acrylic acid) Template" (2013). Faculty Bibliography 2010s. 4938.
https://stars.library.ucf.edu/facultybib2010/4938
Comments
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