Academic literature on the topic 'Diffusion - Organic Dyes'
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Journal articles on the topic "Diffusion - Organic Dyes"
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Smilek, Jiří, Michal Kalina, Marcela Laštůvková, Irena Türkeová, Petr Sedlacek, and Martina Klučáková. "Reactivity-Mapping Tool Based on Diffusion Techniques for Characterization of Biocolloids." Materials Science Forum 851 (April 2016): 130–34. http://dx.doi.org/10.4028/www.scientific.net/msf.851.130.
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The universal reactivity-mapping tool was developed for characterization and study on barrier properties of selected biopolymers. The reactivity of biocolloids (humic acids) was studied by both diffusion techniques (break-through diffusion technique and non-stationary diffusion). The rate of reactivity of humic acids was compared by the interactions with basic cationic organic dye (Methylene Blue) because of the positive interactions among anionic supramolecular humic acids and cationic organic dyes were expected. The reactivity and barrier properties of biocolloids were compared by determination of fundamental diffusion parameters such as effective diffusion coefficient, sorption capacity, break-through time (the time needed for penetration of chosen organic dye through hydrogel porous barrier) or the concentration of organic dye on the interface hydrogel-solution. The original combination of simple diffusion experiments of suitable diffusion probe (organic dye) with the advantages of hydrogel porous media (simple preparation of hydrogels, the diffusion is undisturbed by convection, etc.) provides very valuable information about the reactivity of chosen biocolloids.
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Klučáková, Martina. "Effect of Chitosan as Active Bio-colloidal Constituent on the Diffusion of Dyes in Agarose Hydrogel." Gels 9, no. 5 (May 9, 2023): 395. http://dx.doi.org/10.3390/gels9050395.
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Agarose hydrogel was enriched by chitosan as an active substance for the interactions with dyes. Direct blue 1, Sirius red F3B, and Reactive blue 49 were chosen as representative dyes for the study of the effect of their interaction with chitosan on their diffusion in hydrogel. Effective diffusion coefficients were determined and compared with the value obtained for pure agarose hydrogel. Simultaneously, sorption experiments were realized. The sorption ability of enriched hydrogel was several times higher in comparison with pure agarose hydrogel. Determined diffusion coefficients decreased with the addition of chitosan. Their values included the effects of hydrogel pore structure and interactions between chitosan and dyes. Diffusion experiments were realized at pH 3, 7, and 11. The effect of pH on the diffusivity of dyes in pure agarose hydrogel was negligible. Effective diffusion coefficients obtained for hydrogels enriched by chitosan increased gradually with increasing pH value. Electrostatic interactions between amino group of chitosan and sulfonic group of dyes resulted in the formation of zones with a sharp boundary between coloured and transparent hydrogel (mainly at lower pH values). A concentration jump was observed at a given distance from the interface between hydrogel and the donor dye solution.
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Chenyakin, Yuri, Dagny A. Ullmann, Erin Evoy, Lindsay Renbaum-Wolff, Saeid Kamal, and Allan K. Bertram. "Diffusion coefficients of organic molecules in sucrose–water solutions and comparison with Stokes–Einstein predictions." Atmospheric Chemistry and Physics 17, no. 3 (February 15, 2017): 2423–35. http://dx.doi.org/10.5194/acp-17-2423-2017.
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Abstract. The diffusion coefficients of organic species in secondary organic aerosol (SOA) particles are needed to predict the growth and reactivity of these particles in the atmosphere. Previously, viscosity measurements, along with the Stokes–Einstein relation, have been used to estimate the diffusion rates of organics within SOA particles or proxies of SOA particles. To test the Stokes–Einstein relation, we have measured the diffusion coefficients of three fluorescent organic dyes (fluorescein, rhodamine 6G and calcein) within sucrose–water solutions with varying water activity. Sucrose–water solutions were used as a proxy for SOA material found in the atmosphere. Diffusion coefficients were measured using fluorescence recovery after photobleaching. For the three dyes studied, the diffusion coefficients vary by 4–5 orders of magnitude as the water activity varied from 0.38 to 0.80, illustrating the sensitivity of the diffusion coefficients to the water content in the matrix. At the lowest water activity studied (0.38), the average diffusion coefficients were 1.9 × 10−13, 1.5 × 10−14 and 7.7 × 10−14 cm2 s−1 for fluorescein, rhodamine 6G and calcein, respectively. The measured diffusion coefficients were compared with predictions made using literature viscosities and the Stokes–Einstein relation. We found that at water activity ≥ 0.6 (which corresponds to a viscosity of ≤ 360 Pa s and Tg∕T ≤ 0.81), predicted diffusion rates agreed with measured diffusion rates within the experimental uncertainty (Tg represents the glass transition temperature and T is the temperature of the measurements). When the water activity was 0.38 (which corresponds to a viscosity of 3.3 × 106 Pa s and a Tg∕T of 0.94), the Stokes–Einstein relation underpredicted the diffusion coefficients of fluorescein, rhodamine 6G and calcein by a factor of 118 (minimum of 10 and maximum of 977), a factor of 17 (minimum of 3 and maximum of 104) and a factor of 70 (minimum of 8 and maximum of 494), respectively. This disagreement is significantly smaller than the disagreement observed when comparing measured and predicted diffusion coefficients of water in sucrose–water mixtures.
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Dey, Shantanu, Ujjwal Mandal, Supratik Sen Mojumdar, Amit Kumar Mandal, and Kankan Bhattacharyya. "Diffusion of Organic Dyes in Immobilized and Free Catanionic Vesicles." Journal of Physical Chemistry B 114, no. 47 (December 2, 2010): 15506–11. http://dx.doi.org/10.1021/jp1068347.
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Chernomorova, Maria A., Natali S. Khrabrova, Vladimir A. Zhinzhilo, and Igor E. Uflyand. "The Use of Copper Terephthalate for the Determination and Separation of Organic Dyes via Solid-Phase Extraction with Spectrophotometric Detection." Applied Sciences 13, no. 5 (February 27, 2023): 3063. http://dx.doi.org/10.3390/app13053063.
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In this work, a metal–organic framework (MOF), copper benzene dicarboxylate (Cu-MOF), was tested for the adsorptive recovery of organic dyes (Sunset Yellow FCF, Tartrazine, Orange II, and Methyl Orange) from aqueous solutions. Studies were also carried out to determine the effects of various parameters, and isothermal and kinetic models were proposed. The adsorption capacity of Cu-MOF was much higher than that of activated carbon. The experimental data are best described by the Langmuir isotherm model (R2 > 0.997) and show the ability of Cu-MOF to adsorb 435 mg/g of the dye under optimal conditions. The study of the kinetics of the dye adsorption process followed a pseudo-second-order kinetic model indicating the coexistence of physical and chemisorption, with diffusion within the particles being the rate-limiting step. Thermodynamic studies were also carried out, and they led to the conclusion that the adsorption of the dye was a feasible, spontaneous, and exothermic process (−25.53 kJ mol−1). The high organic dye recovery shows that Cu-MOF can be used as an efficient and reusable adsorbent for the extraction of dyes from aqueous solutions. These studies may lead to economic interest in this adsorbent material for environmental purposes.
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Kadolkar, Prajakta S., Shivaraj A. Patil, Manjunath N. Wari, and Sanjeev R. Inamdar. "Rotational diffusion dynamics of Alexa flour dyes in aqueous organic environment." Journal of Molecular Liquids 312 (August 2020): 113452. http://dx.doi.org/10.1016/j.molliq.2020.113452.
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BALAKRISHNAN, JEYAGOWRI, and YAMUNA RANGAIYA THIAGARAJAN. "CHARACTERIZATION AND POTENTIAL SUITABILITY OF SIMAROUBA GLAUCA SEED SHELL LIGNOCELLULOSIC BIOMASS AS ADSORBENT OF BASIC DYES FROM AQUEOUS SOLUTIONS." Cellulose Chemistry and Technology 55, no. 5-6 (June 30, 2021): 705–22. http://dx.doi.org/10.35812/cellulosechemtechnol.2021.55.60.
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The present study investigates the potential of Simarouba glauca seed shell powder as a cost-effective adsorbent for the removal of the cationic dyes Malachite green (MG), Methylene blue (MB) and Rhodamine B (RB) from aqueous solutions. The adsorbent was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD), as well as by Brunauer–Emmett–Teller (BET) and elemental (CHNS) analyses. Batch mode adsorption studies were carried out varying the experimental conditions, such as initial dye concentration and contact time, adsorbent dose, pH and particle size, in order to assess the adsorbent capacity for the removal of cationic dyes from wastewater. The experimental data were analysed using the Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherms. The data fitted well the Langmuir model for the dyes studied. Kinetic data were analysed using the pseudo-first order, pseudo-second order, intraparticle diffusion and Boyd models. The experimental results showed that the pseudo-second order model fitted well.
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Dollendorf, Christian, Susanne Katharina Kreth, Soo Whan Choi, and Helmut Ritter. "Polymerization of novel methacrylated anthraquinone dyes." Beilstein Journal of Organic Chemistry 9 (February 28, 2013): 453–59. http://dx.doi.org/10.3762/bjoc.9.48.
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A new series of polymerizable methacrylated anthraquinone dyes has been synthesized by nucleophilic aromatic substitution reactions and subsequent methacrylation. Thereby, green 5,8-bis(4-(2-methacryloxyethyl)phenylamino)-1,4-dihydroxyanthraquinone (2), blue 1,4-bis(4-((2-methacryloxyethyl)oxy)phenylamino)anthraquinone (6) and red 1-((2-methacryloxy-1,1-dimethylethyl)amino)anthraquinone (12), as well as 1-((1,3-dimethacryloxy-2-methylpropan-2-yl)amino)anthraquinone (15) were obtained. By mixing of these brilliant dyes in different ratios and concentrations, a broad color spectrum can be generated. After methacrylation, the monomeric dyes can be covalently emplaced into several copolymers. Due to two polymerizable functionalities, they can act as cross-linking agents. Thus, diffusion out of the polymer can be avoided, which increases the physiological compatibility and makes the dyes promising compounds for medical applications, such as iris implants.
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Mandake, Manoj B., Santosh Walke, Makarand Naniwadikar, Ganesh Patil, and Sandhya D. Jadhav. "Experimental Investigations of the Removal of Methylene Blue from Waste Water using Agricultural Adsorbant." Int. J. of Membrane Science and Technology 10, no. 1 (January 20, 2023): 1–7. http://dx.doi.org/10.15379/2410-1869.2023.10.01.01.
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Abstract: The colored organic or inorganic chemical compounds which can impart colour to other substance are the Dyes which did significant applications in the most industrial sectors like the textile industry, leather industry, paper industry, plastic, foodstuff industry etc, to impart color to their products. Due to the large volume of dye use in these businesses, a significant quantity of wastewater containing colored organics is generated. Because of insufficient dye-fiber fixation, during the dyeing process, half of the dye is lost in the wastewater. Peanut and rice husk are used to absorb MB from water. Initial Methylene Blue concentration, Peanut and Rice Husk dose, and pH were monitored and compared to current adsorbents to identify the optimal removal conditions. The equilibrium amount of MB adsorbed at time t (min) for rice husk and peanut hull are obtained as 5.1 and 5.19 mg/g respectively. As part of the research, an intra-particle diffusion model was implemented to regulate the mass transfer model's rate-controlling step mechanism.
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Russo, Mattia, Kirsty E. McGhee, Tersilla Virgili, David G. Lidzey, Giulio Cerullo, and Margherita Maiuri. "Dephasing Processes in the Molecular Dye Lumogen-F Orange Characterized by Two-Dimensional Electronic Spectroscopy." Molecules 27, no. 20 (October 20, 2022): 7095. http://dx.doi.org/10.3390/molecules27207095.
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Molecular dyes are finding more and more applications in photonics and quantum technologies, such as polaritonic optical microcavities, organic quantum batteries and single-photon emitters for quantum sensing and metrology. For all these applications, it is of crucial importance to characterize the dephasing mechanisms. In this work we use two-dimensional electronic spectroscopy (2DES) to study the temperature dependent dephasing processes in the prototypical organic dye Lumogen-F orange. We model the 2DES maps using the Bloch equations for a two-level system and obtain a dephasing time T2 = 53 fs at room temperature, which increases to T2 = 94 fs at 86 K. Furthermore, spectral diffusion processes are observed and modeled by a combination of underdamped and overdamped Brownian oscillators. Our results provide useful design parameters for advanced optoelectronic and photonic devices incorporating dye molecules.
Dissertations / Theses on the topic "Diffusion - Organic Dyes"
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Ullmann, Dagny Anna. "Measurements of diffusion coefficients of organic dyes in proxies of atmospheric particles." Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/61969.
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Smilek, Jiří. "Nové metody studia reaktivity a transportních vlastností biokoloidů." Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2016. http://www.nusl.cz/ntk/nusl-234657.
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The main aim of doctoral thesis was the study on reactivity, transport and barrier properties of biocolloidal and synthetic polymeric substances by simple diffusion techniques. It was studied mainly the influence of basic physic-chemical parameters (temperature, concentration, pH and modification of material) on the reactivity and barrier ability of chosen compounds. Further substances were chosen as a model compounds: biocolloids (humic acids, alginate, chitosan, hyaluronate) and synthetic polymer (polystyrenesulfonate). Reactivity, barrier and transport properties of chosen substances were studied by interactions with oppositely charged basic organic dyes (methylene blue, rhodamine 6G, amido black 10B respectively) in hydrogels medium based on linear polysaccharide (agarose). The attention was also paid to basic physic-chemical characterisation (infrared spectroscopy, rheology, elemental analysis, thermogravimetry and scanning electron microscopy) of chosen materials and also hydrogels. Key part of the whole doctoral thesis was the optimization of selected diffusion techniques (diffusion cell technique and non-stationary diffusion in cuvettes) designated for the study on reactivity and barrier properties of wide range compounds (optimized method should be used as an universal method for simple and fast determination of reactivity of different compounds at given or changing conditions). The rate of reactivity, transport and barrier properties was determined based on fundamental diffusion parameters such as diffusion coefficients, break-through time so called lag time, interfacial concentration of chosen organic dye, apparent equilibrium constant, tortuosity factor, partition coefficient.
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Nunes, Neto Oswaldo [UNESP]. "Estudo dos processos de transporte dependentes de Spin em materiais orgânicos." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/143066.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Materiais e dispositivos baseados em compostos orgânicos desempenham um importante papel em diversas áreas da aplicação tecnológica devido às suas interessantes propriedades eletro-magneto- ópticas, adicionadas às suas características mecânicas únicas, facilidade de processamento, versatilidade de síntese e baixo custo relativo. Apesar do proeminente campo de aplicação destes materiais, muitos aspectos associados à sua ciência básica são ainda pouco compreendidos. Nesse cenário destaca-se o fenômeno de Magnetoresistência Orgânica (OMAR, da sigla em inglês). Tal fenômeno encontra-se associado a variações significativas da condutividade elétrica de dispositivos orgânicos induzidas por pequenos campos magnéticos externos em temperatura ambiente e tem sido observado em diversificados materiais poliméricos e moleculares. No presente trabalho avaliou-se o fenômeno de OMAR apresentado por um Diodo Emissor de Luz baseado na molécula de Alq3. Medidas de Espectroscopia de Impedância Elétrica na presença de um Campo Magnético estático externo (EIE-CM) foram realizadas sobre o referido dispositivo para diferentes temperaturas. Métodos diferenciados de aquisição e manipulação de dados foram empregados a fim de remover a dependência temporal dos sinais tipicamente observados. Os seguintes Efeitos de Campo Magnético (MFE, da sigla em inglês) foram observados sobre a resposta elétrica do dispositivo: (i) redução de cerca de 1% na resistência, efeito praticamente constante para todo o espectro de frequência e; (ii) variações significativas na capacitância, com intensificação do efeito de Capacitância Negativa em baixas frequências. Como suporte para a interpretação dos resultados experimentais foram realizadas simulações empregando-se duas abordagens: Circuitos Equivalentes e Análise de perturbações de pequenos sinais (em inglês, Small Signal Analysis ) via soluções numéricas das equações de transporte de Boltzmann numa aproximação por Drift-Diffusion empregando-se dispositivos simplificados. As análises sugerem que os MFE evidenciados podem estar associados a um aumento da mobilidade efetiva dos portadores de carga e a uma redução na taxa de recombinação bimolecular no dispositivo. Os resultados foram interpretados em termos dos modelos atualmente aceitos para o fenômeno de OMAR. Esta tese também apresenta um estudo de processos de geração e transferência de carga em corantes Cianinas, materiais promissores para aplicações em células solares com absorção no infravermelho. Técnicas de Ressonância de Spin Eletrônico induzida por Luz foram empregadas em blendas destes corantes com o polímero MEH-PPV e com o fulereno (C60) a fim de avaliar, respectivamente, o caráter aceitador e doador de elétrons das Cianinas.
Materials and devices based on organic compounds play an important role in various technological applications, mainly due to their interesting electrical-magneto-optical properties combined with their unique mechanical properties, easy processing, versatility of synthesis and relatively low cost. Despite the prominent application field of these materials many aspects associated with their basic science are still not well understood. In this context the Organic Magnetoresistance phenomenon (OMAR) deserves to be highlighted. This phenomenon is associated with significant changes in the electrical conductivity of organic devices induced by the presence of small external magnetic fields at room temperature, being observed in various polymeric and molecular materials. In this study we have investigated the OMAR phenomenon in Alq3-based OLEDs. Electrical impedance spectroscopy technique in the presence of an external static magnetic field (EIS-MF) was employed in the experiments; distinct temperatures were considered. Differentiated methods of acquisition and data manipulation were employed to remove the typically observed signal time dependence. The following magnetic field effects (MFE) were observed on the electrical response of the device: (i) a constant reduction of around 1% in the resistance over the entire frequency spectrum and; (ii) significant changes in the capacitance followed by an intensification of the negative capacitance effect at low frequencies. Simulations employing two different approaches were carried out for the interpretation of the experimental results: (i) Equivalent Circuits and (ii) Small Signal Analysis via numerical solutions of the Boltzmann transport equations by Drift-Diffusion approach. The results suggest that the observed MFE can be associated with an increase in the effective mobility of the charge carriers and a reduction in the bimolecular recombination rate in the device. The results were interpreted in terms of the currently accepted models for the OMAR phenomenon. This thesis also presents a study about generation and charge transfer processes in cyanine dyes (near infrared absorbing compounds) which are promising materials for applications in solar cells. Light induced Electron Spin Resonance (L-ESR) technique was employed to study the presence/formation of paramagnetic centers in blends of these dyes with MEH-PPV polymer and fullerene (C60) to evaluate, respectively, the electron acceptor and donor character of cyanine dyes.
FAPESP: 2011/21830-6
CNPq: 204432/2013-8
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Kolesa, Pavel. "Studium interakcí barviv s biopolymerem chitosanem." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2016. http://www.nusl.cz/ntk/nusl-240577.
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This master's thesis was focused on the study of interaction of some organic azo dyes (model diffusion probes) with cationic biopolymer chitosan. This interactions were realized via diffusion processes in hydrogel media based on thermoreversible agarose. The main aim was study of influence of pH of solution on the diffusion process. Interactions of used dyes are based on electrostatic character. The aminogroup of chitosan interacts with the functional group of chosen dyes (anionic sulfonic group) and thus affects the process of diffusion. The model diffusion compounds were chosen organic anionic dyes Chicago sky blue 6B (C.I. 24 410), Sirius red (C.I. 35 780) and Reactive blue 49 (C.I. 621 526). The important content of this diffusion method is a monitoring of the time progression of diffusion profile by UV-VIS spectrophotometry. The presented work follows the bachelor thesis and shows comprehensive view of the reactivity of chitosan and its behavior in different systems. Unsteady diffusion in cuvettes appears to be a universal method for the study of reactivity of biopolymers and for the study of transport processes in hydrogel media. The diffusion method is universal, easy and cheap.
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Vezzoli, Massimiliano. "Intrinsic kinetics of titania photocatalysis : simplified models for their investigation." Thesis, Queensland University of Technology, 2012. https://eprints.qut.edu.au/51574/1/Massimiliano_Vezzoli_Thesis.pdf.
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Even though titanium dioxide photocatalysis has been promoted as a leading green technology for water purification, many issues have hindered its application on a large commercial scale. For the materials scientist the main issues have centred the synthesis of more efficient materials and the investigation of degradation mechanisms; whereas for the engineers the main issues have been the development of appropriate models and the evaluation of intrinsic kinetics parameters that allow the scale up or re-design of efficient large-scale photocatalytic reactors.
In order to obtain intrinsic kinetics parameters the reaction must be analysed and modelled considering the influence of the radiation field, pollutant concentrations and fluid dynamics. In this way, the obtained kinetic parameters are independent of the reactor size and configuration and can be subsequently used for scale-up purposes or for the development of entirely new reactor designs.
This work investigates the intrinsic kinetics of phenol degradation over titania film due to the practicality of a fixed film configuration over a slurry. A flat plate reactor was designed in order to be able to control reaction parameters that include the UV irradiance, flow rates, pollutant concentration and temperature.
Particular attention was paid to the investigation of the radiation field over the reactive surface and to the issue of mass transfer limited reactions. The ability of different emission models to describe the radiation field was investigated and compared to actinometric measurements. The RAD-LSI model was found to give the best predictions over the conditions tested. Mass transfer issues often limit fixed film reactors. The influence of this phenomenon was investigated with specifically planned sets of benzoic acid experiments and with the adoption of the stagnant film model. The phenol mass transfer coefficient in the system was calculated to be km,phenol=8.5815x10-7Re0.65(ms-1).
The data obtained from a wide range of experimental conditions, together with an appropriate model of the system, has enabled determination of intrinsic kinetic parameters. The experiments were performed in four different irradiation levels (70.7, 57.9, 37.1 and 20.4 W m-2) and combined with three different initial phenol concentrations (20, 40 and 80 ppm) to give a wide range of final pollutant conversions (from 22% to 85%). The simple model adopted was able to fit the wide range of conditions with only four kinetic parameters; two reaction rate constants (one for phenol and one for the family of intermediates) and their corresponding adsorption constants. The intrinsic kinetic parameters values were defined as kph = 0.5226 mmol m-1 s-1 W-1, kI = 0.120 mmol m-1 s-1 W-1, Kph = 8.5 x 10-4 m3 mmol-1 and KI = 2.2 x 10-3 m3 mmol-1.
The flat plate reactor allowed the investigation of the reaction under two different light configurations; liquid and substrate side illumination. The latter of particular interest for real world applications where light absorption due to turbidity and pollutants contained in the water stream to be treated could represent a significant issue. The two light configurations allowed the investigation of the effects of film thickness and the determination of the catalyst optimal thickness. The experimental investigation confirmed the predictions of a porous medium model developed to investigate the influence of diffusion, advection and photocatalytic phenomena inside the porous titania film, with the optimal thickness value individuated at 5 ìm. The model used the intrinsic kinetic parameters obtained from the flat plate reactor to predict the influence of thickness and transport phenomena on the final observed phenol conversion without using any correction factor; the excellent match between predictions and experimental results provided further proof of the quality of the parameters obtained with the proposed method.
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PORTELLA, MARCIA TEREZA. "Spectroscopie coherente et etude d'un espace poreux par melange a quatre ondes." Paris 6, 1987. http://www.theses.fr/1987PA066586.
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Nous avons construit des lasers qui ont servi a des experiences de melange a quatres ondes (reseau transitoire). Nous avons d'abord etudie la reponse non lineaire du troisieme ordre lorsque le milieu presente un continuum large d'etats (colorants). Le signal obtenu sur le cresyl-violet en film mince de colle cellulosique a ete analyse. La technique du reseau transitoire a ete ensuite utilisee pour caracteriser la dynamique de molecules dans un milieu poreux (vycor) et etudier la geometrie des connexions entre pores. Nous avons etudie la rotation de l'azobenzene en solution soit libre soit contenue a l'interieur de l'espace poreux. Ces experiences peuvent etre realisees sur des echelles allant de la femtoseconde a la seconde, permettant ainsi l'etude tant du temps de coherence que des proprietes de diffusion des materiaux
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Delatour, Thierry. "Mise en évidence par spectrométries optiques de formes tautomères caractéristiques d'un pyridylazo diethylaminophénol." Nancy 1, 1987. http://www.theses.fr/1987NAN10159.
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Étude des structures tautomériques du (bromo-5 pyridyl-2-azo)-2 diethylamino-5 phénol par spectrométrie ir, visible, d'émission visible et de diffusion raman de résonance. Attribution des transitions électroniques et vibrationnelles principales. Seules les structures quinoniques sont observées, la forme azo n'apparaissant pas en quantité détectable
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Yang, Cheng-chung, and 羊振中. "Studies of Finite-Source Dye-Diffusion Thermal Transfer for Doping of Organic Light Emitting Diodes." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/77407633836766141666.
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碩士國立臺灣大學
光電工程學研究所
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Organic light emitting devices (OLEDs) based on molecular organic materials or polymer materials have been extensively studied because of their various merits suitable for flat panel display applications. The capability of solution processing of polymers leads to manufacturing advantage for large-area coating. However, it is found difficult to integrate multicolor polymer materials or devices for full-color displays by conventional coating and sequential photolithography steps. To resolve this issue, printing approaches have been aggressively pursued recently. In this thesis, we propose finite-source dye-diffusion thermal transfer (FS-D2T2) for performing controllable doping of polymer films in OLEDs. In this process, the polymer receiver film is placed in direct contact with the dye-dispersed polymer donor film to permit direct dye-diffusion thermal transfer. We perform a series of experiments of dye diffusion in the poly(N-vinylcarbazole) (PVK) or the poly (N-vinylcarbazole): 2-(4—biphenyl)-5-(4-tert- butylphenyl)-1,3,4-oxadiazole (PVK: PBD) matrix systems and show that it can be modeled by Fick’s diffusion theory. Using this doping process, we demonstrated color tuning & color integration of OLEDs.
Book chapters on the topic "Diffusion - Organic Dyes"
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"Textile Dyes (excluding Reactive Dyes)." In Colour Chemistry, 168–93. 2nd ed. The Royal Society of Chemistry, 2014. http://dx.doi.org/10.1039/bk9781849733281-00168.
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In contrast to the application of pigments, involving mechanical anchoring of discrete solid particles in a polymeric matrix, dyeing relies on equilibrium processes involving diffusion or sorption of dye molecules or ions within the substrate. Dyes are used in the coloration of a wide range of substrates including paper, leather and plastics, but by far their most important outlet is textiles. Textile fibres may be classified into three broad groups: natural, semi-synthetic and synthetic. These fibres share the common feature that they are made up of polymeric organic molecules; however, the physical and chemical natures of the polymers involved vary widely, explaining why each type of fibre essentially requires its own ‘tailor-made’ application classes of dyes. Since textile dyes are almost always applied from an aqueous dyebath solution, they are required to be soluble in water, or, alternatively, to be capable of conversion to a water-soluble form suitable for application. Dyes must firmly attach to the textile fibres to which they are applied in order to resist removal, for example by washing. The dye must distribute itself evenly throughout the material to give a uniform colour, referred to as a level dyeing. Finally, the dye must provide an appropriate range of fastness properties, for example to light, washing, heat, rubbing, etc. This chapter deals with the chemical principles underlying the main application classes of dyes that may be applied to textile fibres, with the exception of the reactive dye class.
Conference papers on the topic "Diffusion - Organic Dyes"
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West, D., D. L. Williams, T. A. King, Z. Ali-Adib, P. Hodge, and D. Dunne. "Dependency of Sidechain Chromophore Orientations on Langmuir-Blodgett Polymer Structures." In Organic Thin Films for Photonic Applications. Washington, D.C.: Optica Publishing Group, 1995. http://dx.doi.org/10.1364/otfa.1995.md.8.
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The LB technique allows optical chromophores to be placed within a predetermined series of organic molecular layers. Moreover, the orientations of the chromophores can be controlled when they are positioned in the apolar tail sections of the amphiphiles that are used. The fragility, the tendency to reorganise and even the diffusion mobility of dyes included in an LB film may be greatly reduced if polymeric materials are used. In addition to thermal and mechanical stability, polymers offer an amorphous structure in the plane of the film layers with a reduction in optical scatter relative to monomer films of materials such as fatty acids[1].
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Horie, Kazuyuki. "New Mechanisms and New Systems of Hole Formation in Spectral Hole Burning." In Spectral Hole-Burning and Related Spectroscopies: Science and Applications. Washington, D.C.: Optica Publishing Group, 1994. http://dx.doi.org/10.1364/shbs.1994.thf1.
Full textAbstract:
A variety of studies on persistent spectral hole burning (PSHB) have been carried out for the last twenty years [1-4], since the discovery of this phenomenon in 1974. The elucidation of electron-phonon interaction, the nature of a zero-phonon line and spectral diffusion in PSHB have been studied intensively together with the research aiming at its possible applicability to ultra-high density optical storage. However, as for the PSHB materials, most of the works have been carried out with porphyrins, phthalocyanines, and quinizarin including their derivatives, several organic dyes, samarium and some other inorganic ions. The number of molecules reported to show hole formation so far is restricted compared to a wide variety of chemical structure of organic molecules. This would be because it is usually thought that for the hole formation the existence of a zero-phonon line in guest molecules for SHB should be accompanied by the occurrence of some photochemical reaction of the guest molecules. A well-known exception on this point is the so-called non-photochemical hole burning (NPHB) [4]. Recently triplet-triplet energy transfer of guest molecule to a host photo-reactive matrix has been reported to be a new family [5] of PSHB systems with new mechanism.
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Sakoda, Kazuaki, and Masayuki Maeda. "Spectral Diffusion in Dye-Doped Deuterated Polymers." In Spectral Hole-Burning and Luminescence Line Narrowing: Science and Applications. Washington, D.C.: Optica Publishing Group, 1992. http://dx.doi.org/10.1364/shbl.1992.pd7.
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The spectral diffusion In dye-doped organic glasses has been one of the most attracting subjects in the field of persistent hole burning spectroscopy. However, the microscopic detail of the mechanism is usually unknown. In this study, we try to clarify it by means of the comparison between deuterated and protonated hydrogen bonding polymers.
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Wilkosz, Aaron, and Sergey Sarkisov. "Beam Splitting in Nonlinear Polymeric Waveguide Induced by Photobleaching." In Organic Thin Films for Photonic Applications. Washington, D.C.: Optica Publishing Group, 1997. http://dx.doi.org/10.1364/otfa.1997.the.12.
Full textAbstract:
Optical beam splitting has been first reported for photorefractive waveguides built by titanium diffusion in LiNbO3 [1,2]. The effect has been qualitatively explained as an appearance of spatial dark solitons in self-defocusing nonlinear medium [3]. Optical splitting has also been observed in pure self-defocusing Kerr media in a two dimensional configuration [4,5] similar to that of a slab waveguide. The splitting effect in this case is apparently associated with dark spatial solitons. This paper presents theoretical and experimental data and discusses a theoretical model developed to study optical beam splitting induced by photobleaching a dye-doped polymeric waveguide, where instant refractive index reaction to light intensity redistribution is replaced by permanent index decrease associated with dye photobleaching.
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Curran, K., and M. Davies. "Spectral Intensity Mapping and Analysis of Dyed Microflows." In ASME 2004 2nd International Conference on Microchannels and Minichannels. ASMEDC, 2004. http://dx.doi.org/10.1115/icmm2004-2333.
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The objective of this work is to develop simple reliable software to observe and quantify diffusion phenomena in microfluidic devices. One of the great advantages of microfluidic technology is that it permits the flow and diffusion of multiple streams in a single channel. The accurate control of a diffusion-based process has applications in bio-analytical chemistry, production of organic compounds and combinatorial chemistry. This method has been discussed in the literature as Laminar Fluid Diffusion Interface technology. It is heavily dependant on the controlled and reproducible introduction of several fluids into one channel and enables the design of separation and detection systems based on laminar fluid diffusion interfaces. A method of analyzing and interpreting the diffusion behavior of multiple microflows using the MATLAB programming language as an image analysis tool is presented here. This paper considers two dimensional brightfield and time series images but the method can be applied to other forms, including fluorescent and three-dimensional images. The approach taken relies on the fact that a digital image stores its colour information in signal channels. The information contained in the channels depends on the colour method being used to define the image. Software-based spectral filtering is performed, yielding three dimensional intensity maps of dyed and clear microflows. These maps can be used to monitor diffusion behavior in a number of different areas simultaneously. Spectral noise reduction techniques are also incorporated without significant reduction in original data quality. The technique is used to determine the aqueous diffusion coefficient of the dye Green S by processing digital images taken at set time intervals of two seconds in a stopped-flow experiment. The approach is applied to microflows in straight, two-dimensional serpentine and three-dimensional serpentine channel configurations.
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Tsuchiya, Jun, Jun-ichi Takahashi, and Hiroshi Tanaka. "Free Volume Model of Thermally Induced Spectral Diffusion." In Persistent Spectral Hole Burning: Science and Applications. Washington, D.C.: Optica Publishing Group, 1991. http://dx.doi.org/10.1364/pshb.1991.the15.
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An organic dye/polymer system, such as free base phthalocyanine (H2Pc) dispersed in polymethylmethacrylate (PMMA), has been interested in as a model material of new mass-storage for photochemical hole burning (PHB)[1]. There are, however, some unsolved problems in applying it to a plactical memory system. That is, the influence of polymers as a matrix over the static and dynamic properties of the system, such as, thermally induced spectral diffussion (TISD), homogeneous and inhomogeneous line width, burning efficiency and so on, has not been solved yet. TISD among them has a strong correlation to micro environment of a polymer dispersing a dye. The disorders in amorphous polymers are seen in wide energy range whose upper limit is determined by the glass transition of polymers. However, the lower limit is still left unknown , although some phenomena are known which are affected by low energy excitation. Recently, hole burning spectroscopy was successfully applied to investigate in the lower energy region [2]. Thermally induced conformation changes of polymers are said to have energy of same size to cause TISD in the lower energy region. Koehler et al. succeeded in explaining the the changes quantitatively from a combination of three independent processes, 1- phonon tunneling process, 2-phonon Raman scattering process and activation process [3]. The material parameters, however, that determine the changes are still unknown. We report TISD results of some dye/polymer systems and correlation between TISD and polymer properties.
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Mao, Xiaole, Sung Yang, and Jeffrey D. Zahn. "Experimental Demonstration and Numerical Simulation of Organic-Aqueous Liquid Extraction Enhanced by Droplet Formation in a Microfluidic Channel." In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-16084.
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Organic-aqueous (phenol) liquid extraction is one of the commonly used DNA purification methods. Effective mass transfer of biological material between the discrete fluid phases is key to achieving efficient extraction when designing microfluidic devices based on this technique. In the microscale regime, mass transfer is often diffusion limited. However, mass transfer can be enhanced through the formation of discrete droplets within a microchannel, which leads to a recirculation flow pattern within the droplet. This recirculation increases the mass transfer rate of material to the organic-aqueous interface. In this study, an experimental and computational examination of sample extraction between the organic and aqueous phases through droplet formation is presented. The experiment is conducted within a converging dual inlet microfluidic channel fabricated in PDMS. By controlling the capillary number of the flow, different flow patterns are created in the channel. The flow patterns are examined using a computational fluid dynamics (CFD) simulation. The CFD model successfully simulates the flow behavior under a variety of flow conditions and provides a closer examination of the internal recirculation pattern within the droplet. The experimental sample extraction utilizes a fluorescent dye localization technique and shows that the droplet flow offers a significant improvement in the speed of sample extraction over diffusional mixing. A preliminary test demonstrates the feasibility of using the droplet formation for fast extraction with biological samples.
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Morales, Mercedes C., and Jeffrey D. Zahn. "Development of a Diffusion Limited Microfluidic Module for DNA Purification via Phenol Extraction." In ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-68086.
Full textAbstract:
Purification of Deoxyribonucleic acid (DNA) by organic-aqueous liquid extraction, also called phenol extraction, is a standard technique commonly utilized in biology laboratories. In order to minimize interaction energies, membrane components and proteins naturally partition to the organic (phenol) phase while the DNA stays in the aqueous phase, where it can be easily removed. In recent years, microfluidics has become a driving force toward more efficient and autonomous platforms for fluid based diagnostics, chemical reaction chambers, separation and preparation of biological materials. In this work, fabrication, and performance of a long microfluidic device for DNA extraction are presented. The devices were fabricated using soft lithography to transfer lithographically defined features into a PDMS structure via replica molding. Stratified-flow experiments using a rhodamine dye conjugated bovine serum albumin protein (BSA) in an aqueous phase were conducted to demonstrate the ability to remove proteins from the aqueous phase into the phenol phase. Additionally, the study of BSA partitioning and DNA isolation in a two-phase system under stratified flow condition were presented, separately and conjunctly. Finally, protein partitioning and DNA recovery obtained with this device could be compared with other types of mixing and extraction such as mixing by droplet formation and electrohydrodynamic (EHD) instability.
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Molaire, M. F. "The Influence of Melt Viscosity on the Writing Sensitivity of Organic Dye-Binder Optical-Disk Recording Media." In Optical Data Storage. Washington, D.C.: Optica Publishing Group, 1987. http://dx.doi.org/10.1364/ods.1987.tha4.
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The object of this work was to determine the relationship between writing sensitivity of organic dye-binder media and media melt viscosity. Writing sensitivity was defined as the recording response against writing laser power. That response was measured by the electronic readout of the recorded pits. As a theoretical framework, the mechanism of hole formation espoused by Wrobel et al. (1) was assumed. That is, pit formation was considered to be essentially a flow process in which the primary driving force is back pressure due to limited material ablation and decomposition. Thus it was believed that diffusion processes were unimportant; consequently, the glass-transition temperature was not expected to be a controlling parameter. As theorized by Kivits et al. (2), it was assumed that friction forces due to viscosity had to be overcome for pit formation. This work was not concerned with the influence of optical efficiency. The work of Howe and Wrobel (3) for optimizing the dye-binder layer for optimum optical performance has been followed.
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Romanovskii, Yu V., R. I. Personov, A. D. Samoilenko, Keith Holliday, and Urs P. Wild. "Concentration Effects on Spectra and Persistent Hole-Burning of Porphyrin Doped Langmuir-Blodgett Films." In Spectral Hole-Burning and Luminescence Line Narrowing: Science and Applications. Washington, D.C.: Optica Publishing Group, 1992. http://dx.doi.org/10.1364/shbl.1992.tub23.
Full textAbstract:
Persistent spectral hole-burning has recently been employed in investigations of pseudo-two-dimensional systems such as porphyrin and organic dye doped Langmuir-Blodgett films [1]. In order to perform spectral measurements on such ultra-thin materials, especially in the case of monolayers, the necessity to work with highly concentrated samples arises. For example, in a spectral hole-burning study of porphyrin centres in a multilayer assembly [2], the average distance between chromophores was about 3.5 nm which is of the same order as the Forster radius for energy transfer. Energy transfer and aggregation of impurities at high concentrations may strongly interfere with other processes under investigation such as optical dephasing and spectral diffusion. The effect of impurity concentration on spectral properties is an effective way of determining the dominant processes. Some data has already been published for conventional bulk systems such as tetracene doped alcohol glass [3] and chlorin and tetraphenylporphyrin doped polystyrene [4]. Here we present results of investigations of concentration effects on spectra and hole-burning of impurity doped Langmuir-Blodgett films.