• Textile Coloration and Finishing
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• v.24 no.3
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• pp.153-157
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• 2012

One of organic dye materials which have been long lasting investigated is rhodamine 6G dye series. This dye has been attracted with considerable interests due to the reason of its promising photochemical properties. In this study, a novel fluorescent dye compound based on rhodamine 6G derivative was synthesized through the reaction of rhodamine 6G hydrazide and indole-3-carboxaldehdyde. Absorption and fluorescent emission spectra of this dye were determined with the properties of solvatofluorochromism. Related electron energy states of the dye compound were also characterized by computational calculations.

• Journal of Environmental Science International
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• v.21 no.6
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• pp.655-659
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• 2012

This study elucidates the COD removal of dye (Rhodamine B) through electrochemical reaction. Effects of current density (7.2 to 43.3 $mA/cm^2$), electrolyte type (NaCl, KCl, $Na_2SO_4$, HCl), electrolyte concentration (0.5 to 2.0 g/L), air flow rate (0 to 4 L/min) and pH (3 to 11) on the COD removal of Rhodamine B were investigated. The observed results showed that the increase of pH decrease the COD removal efficiency. Whereas, the increase of current density;NaCl concentration and air flow rate caused the increase of the COD removal of Rhodamine B.

• Bulletin of the Korean Chemical Society
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• v.32 no.2
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• pp.519-523
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• 2011

We studied the detection of the Hg(II) concentration in an aqueous solution using rhodamine dyes on citrate-reduced Au nanoparticles (NPs). The quenching effect from Au NPs was found to decrease as the Hg(II) concentration increased under our experimental conditions. As the fluorescence signals intensified, the surface-enhanced Raman scattering (SERS) intensities reduced on the contrary due to less rhodamine dyes on Au NPs as the Hg(II) concentration increased. The rhodamine 6G (Rh6G) and rhodamine 123 (Rh123) dyes were examined via fluorescence and SERS measurements depending on Hg(II) concentrations. Fast and easy fluorescence detection of an Hg (II) concentration as low as a few ppm could be achieved by naked eye using citrate-reduced Au NPs.

• Textile Coloration and Finishing
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• v.25 no.2
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• pp.83-88
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• 2013

Rhodamine dyes have been studied in various scientific areas due to their excellent photophysical properties. In particular, these rhodamine dyes are one of the most famous fluorophores as signal unit in chemosensor study. This is related to spirolactam ring system in rhodamine dyes. When the spirolactam ring is closed, there is nonfluorescence and colorless. Whereas, ring-opening of the corresponding spirolactam induces strong fluorescence and color. These absorption and emission changes are related to structural changes as well as electron energy potential levels such as HOMO and LUMO values. In this study, two different structures of rhodamine 6G hydrazide depending on the spirolactam ring system were investigated using absorption measurement, electrochemical measurement and computational calculations.

• Clean Technology
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• v.21 no.3
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• pp.178-183
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• 2015

Lead molybdate (PbMoO₄) oxides were successfully synthesized using a conventional hydrothermal method and a microwave-assisted hydrothermal method. They were characterized by XRD, DRS, BET, Raman, SEM and PL. We also investigated the photocatalytic activity of these materials for the decomposition of Rhodamine B under UV-light irradiation. From XRD and Raman results, well-crystallized PbMoO₄ crystals have been successfully synthesized regardless of preparation method and had 42~59 nm particle size. The PbMoO₄ catalysts prepared using microwave-assisted process had the similar particle size and enhanced the photocatalytic activity when compared to that prepared by hydrothermal method. The PbMoO₄ catalysts prepared under the irradiation of microwave for 75 min showed the highest photocatalytic activity. The PL peaks appears at about 530 nm at all catalysts and it was also shown that the excitonic PL signal is proportional to the photocatalytic activity for the decomposition of Rhodamine B.

• Analytical Science and Technology
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• v.10 no.3
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• pp.225-229
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• 1997

The stability of Rhodamine 6G Perchlorate(Rh6GP) doped in organically modified silicate(Ormosil) was investigated after the Ormosil was synthesized by sol-gel process. The composition of the Ormosil which makes organic dye molecules stable and dimer-free was decided from comparing absorption peaks of dye molecules in sol state, in wet gel and in completely dried gel. The stable and dimer-free Rh6GP doped in the Ormosil was achieved in the 0.1 molar ratio of HCl/TEOS.

• Journal of Environmental Science International
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• v.14 no.12
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• pp.1195-1201
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• 2005

In order to develop a dye coloring technology on Conchiolin layer in cultured pearls, appropriate dyes were selected, their solubilities in various solvents were studied, and adsorption and desorption experiments were performed. Solubilities of several basic dyes known to suitable for the pearl coloring, i.e., Rhodamine 6G(R6), Rhodamine B(RB) and Methylene Blue(MB), in several solvents (distilled water, methanol, ethanol, and acetone) were investigated. Among these dyes, R6 was chosen as a dye for single component adsorption and desorption experiment due to the relatively good solubility in various solvents tested. Solubilities of dyes were judged to be enough to color the pearls since dye concentrations in pearl coloring are, in general, not so high. The internal surface area of the pearl layer is believed to be directly related to the dye adsorption, the single-point internal surface area of the pearl layer measured at the nitrogen relative pressure of 0.3 was found to be $0.913m^2/g$, and the BET internal surface area, $1.01m^2/g$ The most probable diameters of micropores and macropores were found to be $40{\AA}$and $5000{\AA}$ respectively, from the pore size distribution data. Adsorption isotherm was well fitted to the Langmuir isotherm model, resulting in q=$\frac{1.62C}{1+1.09C^{.}}$

• Journal of Environmental Science International
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• v.22 no.10
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• pp.1273-1278
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• 2013

Novel rhodamine 6G fluorescent chemosensors 1 and 2 for the detection of transition metal cations were synthesized through the condensation of rhodamine 6G ethylenediamine with each of 2-hydroxy-1-naphthaldehyde and 2,6-pyridinedicarbaldehyde, respectively. 1 and 2 were characterized using $^{13}C$ NMR, $^1H$ NMR and mass spectroscopy. Fluorometric and colorimetric measurements involving various metal ions revealed the ring opening of the rhodamine 6G spirocycle framework. In the absence of metal cations, 2 was colorless and non-fluorescent, whereas the addition of metal cations ($Hg^{2+}$ and others) changed the color to pink, accompanied by the appearance of an orange fluorescence. The chemosensors exhibited high selectivity for $Hg^{2+}$ over other divalent first-row transition metals. The complexes of $Hg^{2+}$ with 1 and 2 were successfully isolated. A huge enhancement in the fluorescence for both one- and two-photon excitations makes these compounds suitable candidates to be used for fluorescent labeling of biological systems.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3381-3386
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• 2013

This paper reports a method using molecularly imprinted polymers that are grafted onto the surface of carboxyl-modified multi-walled carbon nanotubes as the solid-phase extraction adsorbents to detect Rhodamine B in chili powder samples. The polymers were characterized by FTIR and TGA. Various parameters which probably influence efficiency of extraction were optimized. The analytical parameters such as precision, accuracy and linear working range were also determined in optimal experimental conditions. And the proposed method was applied to analysis of Rhodamine B in chili powder samples. The limits of detection and quantification were 2.57 and 8.56 ${\mu}g/g$, respectively. The recoveries for analytes were higher than 95% and relative standard deviation values were found to be in the range of 0.83-4.15%. This method was successfully applied for the determination of Rhodamine B.

• Bulletin of the Korean Chemical Society
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• v.32 no.spc8
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• pp.2928-2932
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• 2011

A chemosensor based on a rhodamine-hydroxamate platform containing a pyridine and a cyclen binding units has been developed for the detection of $Cd^{2+}$ in aqueous solutions. The probe responds selectively toward $Cd^{2+}$ over other biologically relevant metal ions. The fluorescent probe shows 1:1 binding stoichiometry and the detection limit for $Cd^{2+}$ in water proved to be as low as 25 nM.