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Rhodamine 6G – polymethylmethacrylate/polycarbonate (Rh6G–PMMA/PC) were prepared by a casting method at room temperature with diverse volume ratios of Rh6G dye solution (5, 10, 15, 20 and 25) ml. The as-prepared films were categorised via UV–Vis spectrophotometer, and the optical properties were investigated in the wavelength range of (200-800) nm. The absorption peaks for pure PMMA/PC film were affected by inserting Rh6G dye solution, the wavelength of absorption peak of pure PMMA/PC film is at 300 nm and 340 nm while there are different behaviour at different concentration of RG6 after mixing with PMMA/PC films; there are red shift for concentrations (10 and 25 ml) of RG6 after mixing with PMMA/PC films by appear another peaks at 530 nm and 535 nm respectively. In addition, there is a blue shift for concentrations (15 and 20 ml) of RG6 after mixing with PMMA/PC films, as evidenced by the appearance of new peaks at wavelength 265 nm. Furthermore, new peaks appeared and were absorbed while the energy band gap was influenced, with values ranging from 4.3 eV for pure PMMA/PC film to 4.18 eV for mixtures 10 & 25 ml concentration of Rh6G/ PMMA/PC belonging to the red shift to 4.9 eV and 4.85 eV for mixtures 15 and 20 ml concentration of Rh6G/ PMMA/PC belonging to the blue shift. [ABSTRACT FROM AUTHOR]

This work studies the improvement of the emission spectra of polyacrylic acid (PAA) by adding different ratios of rhodamine dye (RhB) to different sizes and shapes of gold nanoparticles (AuNPs). AuNPs were prepared by chemical reduction method at heating temperature 80°C and a different time. The experimental results of both UV–Visible spectroscopy and TEM technique showed that the AuNPs were formed at different times (1–15 min) with different plasmonic band positions and has particle sizes 11 and 13 nm, for AuNPs were formed at 1 and 10 min respectively. FTIR, UV–Vis, X-ray diffraction, and SEM techniques used in the characterization of PAA blended by an equivalent amount of RhB and AuNPs with size 11 and 13 nm. The band appeared at 1683 cm−1 in PAA spectra which is assigned to C=O became doubling in the PAA blended samples due to the AuNPs may be coordinating with the oxygen atom in the C=O group. Fluorescence measurements indicated an emission band appeared at 585 and 590 nm for PAA doped by RhB and AuNPs with size 11 and 13 nm, respectively. The intensity of these emission bands was enhanced for the PAA blended by increasing both AuNPs and RhB ratios due to the interactions between dipole moments of the SPR of the AuNPs and RhB molecules. Therefore, it could be enhancing the fluorescence intensity of these samples, and it can be used as an laser active medium. Highlights Synthesis of AuNPs with different sizes. Prepare PAA blended by RhB and AuNPs. Study the coordination of AuNPs with PAA using FTIR. Explain the effect of RhB and AuNPs on fluorescence spectra.

Pure blend Polycarbonate- Polystyrene (PC-PS) and doped blend films with various volume of Coumarin dye were prepared by using the casting method. The absorption and transmission spectra for these films were measured using UV/VIS spectrometer technique in order to assess the type of transition which was found to be an indirect transition. The optical energy gaps of pure PC was 4.24 eV, pure PS was 4.39 eV, Coumarin dye was 4.08 eV, and the pure blend was 4.1 eV. After doping blend with Coumarin dye, the energy gap was decreased by 0.06 eV in a volume of 12 ml. The results showed that the absorption coefficient and energy band gap are affected by doping. When the Coumarin dye was added to the pure blend with different concentrations (12, 24, 36, and 48) ml, the FTIR spectrum was affected by the disappearance of peaks and appearance of new ones. [ABSTRACT FROM AUTHOR]

DC conductivity of PVA-g-AA doped films including various Eosin B ratios (0.01, 0.03, 0.05, 0.07, 0.09, 0.12 and 0.15)% Wt in this study, are studied. Through casting techniques, the composite materials have been prepared. Thermogravimetric analysis (TGA), Fourier Transform Infrared Spectroscopy (FT-IR) and X ray diffraction (XRD) analysis have characterized the preparation of PVA-g-AA composites that found the formation of the composite and the adipic acid presence in polyvinyl alcohol. Studies of DC conductivity demonstrate all composites in thermally activated behavior. Conductance has been found to reduce with increasing temperature showing the semi-conductive behaviour for all doping ratios. With doping ratios in coloring and increasing temperature, the activation energy reduced. Maximum conductance in polyvinyl alcohol has been measured in 0.15% of dye. In sensor technology, Dye sensitization of performing polymeric materials had acquired practical application and wide theoretical interest. The current study provides the effect of polymer presence of dye (conductivity, structure and properties), dye sensitized photo sensors and application in sensors. At the end, advantages and perspectives were included of sensitizing polymers or modifying dye in sensors. [ABSTRACT FROM AUTHOR]

This work studies the improvement of the emission spectra of polyacrylic acid (PAA) by adding different ratios of rhodamine dye (RhB) to different sizes and shapes of gold nanoparticles (AuNPs). AuNPs were prepared by chemical reduction method at heating temperature 80°C and a different time. The experimental results of both UV–Visible spectroscopy and TEM technique showed that the AuNPs were formed at different times (1–15 min) with different plasmonic band positions and has particle sizes 11 and 13 nm, for AuNPs were formed at 1 and 10 min respectively. FTIR, UV–Vis, X-ray diffraction, and SEM techniques used in the characterization of PAA blended by an equivalent amount of RhB and AuNPs with size 11 and 13 nm. The band appeared at 1683 cm−1 in PAA spectra which is assigned to C=O became doubling in the PAA blended samples due to the AuNPs may be coordinating with the oxygen atom in the C=O group. Fluorescence measurements indicated an emission band appeared at 585 and 590 nm for PAA doped by RhB and AuNPs with size 11 and 13 nm, respectively. The intensity of these emission bands was enhanced for the PAA blended by increasing both AuNPs and RhB ratios due to the interactions between dipole moments of the SPR of the AuNPs and RhB molecules. Therefore, it could be enhancing the fluorescence intensity of these samples, and it can be used as an laser active medium. Highlights Synthesis of AuNPs with different sizes. Prepare PAA blended by RhB and AuNPs. Study the coordination of AuNPs with PAA using FTIR. Explain the effect of RhB and AuNPs on fluorescence spectra. [ABSTRACT FROM AUTHOR]

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In this study, we investigated the effect of Bromocresol green dye (BCG) of the PMMA thin films optical properties. Films of Poly Methyl Methacrylate doped by 10% BCG doping ratio to prepared two concentrations 2x10-4 and 6x10-4 M of PMMA-BCG dye were deposited on glass substrate using free casting method at room temperature. The optical properties of the films were determined using UVVisible absorbance and transmittance spectra at the 300 - 900 nm wavelength range. The linear absorption coefficient and the extinction coefficient were calculated. The results showed that the optical properties were increasing by increasing the dye concentration, while the optical energy gap was decreasing with the doping. Also from the linear optical properties result the PMMA-BGC thin films are a promised materials for nonlinear optics applications. [ABSTRACT FROM AUTHOR]

Dye-doped polymer films of Poly(methyl methacrylate) PMMA have been prepared with the use of the conventional solution cast technique. Natural dye has been extracted from environmentally friendly material of green tea (GT) leaves. Obvious Fourier transform infrared (FTIR) spectra for the GT extract were observed, showing absorption bands at 3401 cm-1, 1628 cm-1, and 1029 cm-1, corresponding to O-H/N-H, C=O, and C-O groups, respectively. The shift and decrease in the intensity of the FTIR bands in the doped PMMA sample have been investigated to confirm the complex formation between the GT dye and PMMA polymer. Different types of electronic transition could be seen in the absorption spectra of the dye-doped samples. For the PMMA sample incorporated with 28 mL of GT dye, distinguishable intense peak around 670 nm appeared, which opens new frontiers in the green chemistry field that are particularly suitable for laser technology and optoelectronic applications. The main result of this study showed that the doping of the PMMA polymer with green tea dye exhibited a strong absorption peak around 670 nm in the visible range. The absorption edge was found to be shifted towards the lower photon energy for the doped samples. Optical dielectric loss and Tauc's model were used to estimate the optical band gaps of the samples and to specify the transition types between the valence band (VB) and conduction band (CB), respectively. A small band gap of around 2.6 eV for the dye-doped PMMA films was observed. From the scientific and engineering viewpoints, this topic has been found to be very important and relevant. The amorphous nature of the doped samples was found and ascribed to the increase of Urbach energy. The Urbach energy has been correlated to the analysis of X-ray diffraction (XRD) to display the structure-properties relationships. [ABSTRACT FROM AUTHOR]

In the present study four BODIPY (boron dipyrromethene: 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) dyes with π-extended substituents in C-8 position were investigated in solvents and polymer mediums. High aggregation degree was observed for the dyes in the solid state. Association and twisted intramolecular charge transfer processes were found to affect the spectral properties of the compounds causing bathochromic shifts in absorption and fluorescence spectra. The extension of substituent π-conjugation gains molecular association evoked presumably by π-π interaction between the substituents of the adjacent molecules. Photostability of the complexes in different forms was analyzed and the distorted form stabilized by polymer matrix was found to be the most stable. The substituent nature did not affect strongly the photostability of dyes. Displacement of monomer-associate equilibrium in hybrid materials with polymethylmethacrylate and poly(9-vinylcarbazole) was exploited for tuning spectral characteristics of the materials. Two dyes readily forming aggregates at the lowest concentrations were applied for the fabrication of organic light-emitting diodes. The fabricated devices exhibited electroluminescence in the appropriate spectral ranges with moderate efficiency. [ABSTRACT FROM AUTHOR]

Dye-doped polymer films of Poly(methyl methacrylate) PMMA have been prepared with the use of the conventional solution cast technique. Natural dye has been extracted from environmentally friendly material of green tea (GT) leaves. Obvious Fourier transform infrared (FTIR) spectra for the GT extract were observed, showing absorption bands at 3401 cm−1, 1628 cm−1, and 1029 cm−1, corresponding to O–H/N–H, C=O, and C–O groups, respectively. The shift and decrease in the intensity of the FTIR bands in the doped PMMA sample have been investigated to confirm the complex formation between the GT dye and PMMA polymer. Different types of electronic transition could be seen in the absorption spectra of the dye-doped samples. For the PMMA sample incorporated with 28 mL of GT dye, distinguishable intense peak around 670 nm appeared, which opens new frontiers in the green chemistry field that are particularly suitable for laser technology and optoelectronic applications. The main result of this study showed that the doping of the PMMA polymer with green tea dye exhibited a strong absorption peak around 670 nm in the visible range. The absorption edge was found to be shifted towards the lower photon energy for the doped samples. Optical dielectric loss and Tauc’s model were used to estimate the optical band gaps of the samples and to specify the transition types between the valence band (VB) and conduction band (CB), respectively. A small band gap of around 2.6 eV for the dye-doped PMMA films was observed. From the scientific and engineering viewpoints, this topic has been found to be very important and relevant. The amorphous nature of the doped samples was found and ascribed to the increase of Urbach energy. The Urbach energy has been correlated to the analysis of X-ray diffraction (XRD) to display the structure-properties relationships.

The third-order nonlinear optical properties are used in high speed telecommunications, optical limiters and optical computers. The purpose of the study is to determine the third-order nonlinear characteristics of bromothymol blue dye in both polymer and liquid mixtures. The samples are prepared by dissolving dye of different concentrations in methanol and ethanol and thin film was prepared by bulk polymerization technique. The spectral characteristics of the dye are studied by recording the absorption and fluorescence spectra of the dye doped in poly(methylmethacrylate) modified with additives ethanol and methanol and the dye in MMA with additives (liquid mixture). The spectral results of the dye doped polymer rod are compared with dye in liquid mixture. The nonlinear measurements of the dye in liquid and polymer medium were performed using CW Nd:YAG laser of wavelength 532 nm by employing Z-scan technique. The closed Z-scan of the samples exhibited a negative nonlinear refractive index, which is larger in magnitude in solid film compared to that in solution. The open Z-scan in solution and solid samples displayed reversible saturable absorption. [ABSTRACT FROM AUTHOR]

Self-organization and arrangement of supramolecular structures from block-copolymers are some of the ways used for the development of nanoporous and mesoporous polymers. Herein, reactive olygomers can play the key role in the design of supramolecular arranging of polymers. Optically transparent mesoporuos block-copolymers with adjusted free volume are obtained by the polyaddition of 2,4-toluene diisocyanate (TDI) to anionic macroinitiators. The mechanism of polyaddition of TDI to an anionic macroinitiator in various chemical solvents was studied by infrared spectroscopy. It is established that the reaction of forming polyisocyanate blocks of acetal nature (O-polyisocyanate) and stabilization of end O-polyisocyanate chains are based on the formation of voids in polymer. The formation of voids is conditioned by the geometry of self-organization of block-copolymers containing end potassium-O-polyisocyanates stabilized by crown ether fragments. The formation of urea with the participation of isocyanate groups ofortho-location of TDI is one of the main factors of the stabilization of O-polyisocyanate blocks. The investigation of the polymer sorption properties was carried out by electron spectroscopy. As an adsorbed dye Rhodamine 6G was used. The ability of Rhodamine 6G to sorb depended on the content of the O-polyisocyanate component in the polymer. Mesoporous polymers demonstrated high efficiency as an optically transparent matrix for laser-active media with high radiation stability. Rhodamine 6G in mesoporous polymers retains spectral luminescent properties and generates laser radiation during excitation by the second harmonic of Nd:YAG laser. [ABSTRACT FROM AUTHOR]

Abstract: The quest for materials exhibiting high nonlinear refraction and absorption are required for photonic device application. In this paper we report a simplified Z-scan technique, to study the optical nonlinearity of the dye bromocresol purple in methanol and ethanol for different concentration and dye doped polymer film at the wavelength 532nm of Nd:YAG laser. The experimental results show that the investigated organic dye molecule exhibits saturation absorption and negative nonlinearity. The nonlinear absorption co-efficient and the nonlinear refractive index were measured for the dye doped film, and for dye in methanol and ethanol at the concentration of 0.03mM and 0.05mM. The measured third order susceptibility was found to be of the order of 10−6 e.s.u. in both solid and liquid medium. The result shows that the dye has potential applications in nonlinear optics. [Copyright &y& Elsevier]

Significant enhancement of the thermal stability of the hologram recorded on photochromic materials had been achieved via covalent bonding of the photochromic dye to the polymer matrix as compared to the host-guest systems. One time partial reduction of the hologram’s initial diffraction efficiency due to thermal exposure was observed for both—polymers with attached dye as well as hostguest materials. Such one time reduction is interpreted to be due to the thermal relaxation of the polymer network induced with photochromic transition in the dye molecule. A gradual hologram erasure at elevated temperatures was observed for the host-guest system, which is assumed to be due to dye’s diffusion between highly lit and dark areas. For the photochromic materials with covalent boding of the dye to the polymer matrix the level of thermal stability is demonstrated such that at temperatures ca. 100C there was no detectable diffusion type degradation of the hologram after 6 hours of exposure to elevated temperature. Same heating of the hologram in photochromic host-guest polymer led to a full hologram erasure within 40 minutes. In both cases the one time initial DE reduction due to polymer matrix relaxation at elevated temperatures had comparable value of about 0.5 of hologram’s initial DE. [ABSTRACT FROM AUTHOR]

Abstract: Organic dye materials doped in poly-methyl methacrylate matrix were used as spectral converters to increase the energy efficiency of a flash-lamp pumped Nd:YAG laser. In this process, the useless part of emitted spectrum from the pumping lamp is absorbed by dye molecules and, subsequently, re-emitted at longer wavelengths where the narrow absorption line of neodymium ion at about 580nm can be used more efficiently. As a result, approximately 40% enhancement in energy efficiency was achieved. [Copyright &y& Elsevier]

Volume hologram recording is implemented experimentally in the bulk of diarylethene dyedoped polymeric host-guest material. A wide range of reciprocity for holographic imaging is demonstrated, ranging from as low as 0.55 mW/cm2 up to more than 200 mW/cm2. At a dye concentration of 2 × 10−3 M and spatial frequency of 2000 mm−1, refractive index modulations Δ n of 2 × 10−5 at λ = 514.5 nm and 1 × 10−5 at λ = 830 nm were attained. Increasing the dye concentration to 3.8 × 10−2 M resulted in higher Δ n values of 3.8 × 10−4 at λ = 514.5 nm and 2.1 × 10−4 at λ = 830 nm. The high fatigue resistance of the dye allows multiple record/erase cycles without degradation. The thermal stability of the dye allows for durability of the recording material at temperatures above 115°C. At temperatures above 57°C, the hologram is found to exhibit thermal degradation at a rate far exceeding that caused by thermochromism. It is suggested that diffusion of the dye in the polymer matrix is responsible for the increased sensitivity of the hologram to elevated temperatures, which may be applied in reusable holographic thermal sensors. [ABSTRACT FROM AUTHOR]

Abstract: In this article the effects of different parameters such as sample thickness, concentration of dye in the polymer and the laser pump power, on the temperature dependence of the laser-induced birefringence in azo dye doped polymer films were investigated. DR1-PMMA, DR13-PMMA and MR-PMMA samplers are studied. It is found that the peak temperature at which the induced birefringence is maximum varies depending on the mentioned parameters. Although we might get larger induced birefringence by varying parameters, however the stability of the signal by fluctuation in the temperature might be more important in most applications. In order to achieve more stability, the peak temperature should be around the working temperature. It is possible to tune the peak temperature to the working temperature by optimizing the parameters such as concentration, thickness and pump power for each sample. [Copyright &y& Elsevier]

We report the nonlinear interferometric and spectral studies of photoinduced changes of the complex refractive index in azo dye doped polymers. A simple theoretical analysis is used that describes rather well the experimental results when a dominant nonlinearity due to the photoexcitation mechanism, is present. The approach is used to study the behavior of chromophores in different aging stages of the host. [Copyright &y& Elsevier]