Papers by Keyword: Rhodamine 6G

Abstract: Fluorescence polarization and emission spectra of Rhodamine 6G solution with gold nanoparticles have been studied. It is found that the emission intensities tend to be low when the gold nanoparticles are added into the solution partly due to the energy transfer from the Rhodamine 6G to gold nanoparticles. The fluorescence polarization increases as the concentration ratio of the gold and Rhodamine 6G is more than 124 and decreases as the ratio is about 1115. The enhancement and reduction of fluorescence polarization values are understood as the shortening of the fluorescence lifetime and a temperature effect from the heating of gold nanoparticles, respectively.

Abstract: A sol-gel technique has been used to synthesize silver decorated silica nanospheres for surface enhanced Raman scattering (SERS) substrates. X- Ray diffraction (XRD) spectra shows peak at 2θ = 38.1, 44.6, 64.7, and 77.5^° confirming the presence of Ag nanoparticles on the substrates. The Ag- decorated silica nanospheres were applied as SERS substrates using Rhodamine 6G (R6G) as probe molecule. From Raman analysis, the highest SERS enhancement factor at R6G concentration of 10² was calculated around ~10¹⁰.

Abstract: inorganicorganic hybrid nanoparticles between phosphotungstic acid (PTA) and rhodamine 6G (R6G) were synthesized by mixing a solution of 0.1 mmol R6G in ethanol (40 mL) and 40 mL of aqueous solution of PTA (0.2 g). The as-prepared PTA-R6G nanoparticles were characterized by scanning electron microscopy (SEM), UV-vis spectra, and Fourier transform-infrared (FT-IR) spectra. The SEM studies show that the PTA-R6G nanoparticles have an average diameter of about 111 nm and the atomic ratio of W to P is 12.7:1, near to the chemical stoichiometry of PTA. UV-vis spectra confirm that the R6G aggregates formed in PTA-R6G nanoparticles are J-type. The Keggin structure of PTA is maintained in the PTA-R6G hybrid nanoparticles, as demonstrated by FT-IR.

Abstract: We demonstrated a cost-effective and simple method of fabricating Ag-decorated polymer nanorod (ADPN) array by the combination of fabricated by the combination of photochemical reduction and nanoimprint technology. Here, nanoimprint lithography is utilized to fabricate polymer nanorod array as the periodic temple. Subsequently, ADPNs array can be achieved via UV irradiating. The as-synthesized ADPNs array exhibited a remarkable SERS activity and Raman signal reproducibility to rhodamine 6G, a concentration down to 10¹¹ M can be identified. Our results revealed that the ADPN array is a highly desirable candidate as the reliable enhancer for high performance SERS analysis.

Abstract: O₃ reacted with KI-H₃BO₃ absorption solution to produce I₂ which can combine with the excess I- to form I₃-. In pH 4.0 HAc-NaAc buffer solution, I₃- reacted with rhodamine 6G (Rh6G) to form Rh6G-I₃ association particles, which exhibited a great decreasing at 525 nm. Under the chosen conditions, the decreased intensity ΔA was linear to I₂ concentration in the range of 0.5×10^-6-33×10^-6 mol/L. Thus, a highly sensitive and selective spectrophotometric method was proposed to detect O₃ in the air, since the concentration of O₃ was equal to that of I₂ in this reacted system.

Abstract: A simple catalytic kinetic spectrophotometric method was developed for the determination of trace Ru (III) in the range of 0.033–1.00 μg/L. The method is based on the catalytic effect of Ru (III) on the oxidation of rhodamine 6G (Rh 6G) by bromate in micellar media. The reaction was monitored spectrophotometrically by measuring the decrease in the absorbance of Rh 6G at 520 nm with a fixed-time method. The limit of detection is 0.010 μg/L Ru (III). The relative standard deviation for the determination of 0.010 and 0.020 μg/25mL Ru (III) was 2.9 % and 2.5 %, respectively. The method was applied to the determination of Ru (III) in some ores and metallurgy products.

Abstract: Continuously tunable random laser basing on rhodamine 6G was achieved. Wavelength tuning was implemented by wedge-shaped sample shift relatively to the pump beam. The physical base of the tuning method is gain band shift caused by reabsorption. We ascertained that two medium thickness ranges of significantly different tune efficiency exist. The lasing characteristics of the laser were investigated depending on active medium and pump beam parameters. The feedback formation mechanisms in the random lasers of different thickness were analyzed.

Abstract: The behaviour of the luminescence spectra of the organic dye R6G in a multiple scattering polymer matrix was studied with reference to the parameters of the scattering media. It was found that some of the luminescent parameters depend on the concentration of scattering particles, the refractive index of the scattering particles and the sample thickness. As it was shown, that the reason for these dependences is the reabsorption of luminescence light enhanced by multiple light scattering. In addition, an increase in the absorption caused by multiple scattering was observed.

Abstract: We investigated the lasing spectra of multiple scattering active media based on solid polymer solutions of rhodamin 6G with embedded scattering silica particles of mean diameter 500nm. Lasing in these samples appears without any cavity and arises even in rather small active volume 0.05*0.5*0.5mm3. In a thick sample positive feedback for lasing is provided mainly by multiple scattering of light. In a thin sample the feedback is provided both by multiple scattering of light on the particles and light reflection from the sample surface. It is found that the lasing spectra peak wavelength can be varied within 13nm by varying sample thickness in a range 0.1 -1.65mm. A method of continuos laser tuning by wedge-like sample shift with respect to the pump beam is proposed. The presented results are aimed at the development of a new type of microlaser.