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Colbrook, Richard. "Pyroelectric Langmuir-Blodgett films." Thesis, University of Oxford, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.257662.
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Júnior, Antonio Riul. "Filmes de Langmuir e Langmuir-Blodgett de Polianilinas." Universidade de São Paulo, 1998. http://www.teses.usp.br/teses/disponiveis/88/88131/tde-03052010-171319/.
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Explorou-se a caracterização de monocamadas e filmes LB de polianilina (PANi), e um oligômero de polianilina, chamado aqui de 16-mero, com estearato de cádmio (CdSt). A análise dos filmes de Langmuir indicou que possivelmente não há mistura em nível molecular da PANi e do 16-mero com CdSt, ainda que a quantidade adicionada em solução de polímero ou oligômero influencie a estabilidade das monocamadas. Utilizou-se UV-vis, FTIR, difração de raios-X, condutividade elétrica, elipsometria, microscopia óptica e potencial de superficie para caracterização dos filmes LB. Os resultados de UV-vis indicaram uma transferência uniforme e ainda que os filmes recém depositados encontram-se desdopados. A análise de FTIR confirma a presença de CdSt nos filmes LB, e o efeito de desdopagem em subfases neutras, corroborando os resultados de UV-vis. A difração de raios-X indica a presença de domínios separados de PANi (e 16-mero) com CdSt nos filmes LB. Resultados elipsométricos indicaram uma espessura por camada em tomo de 25 Å. A excelente uniformidade obtida nos filmes LB mistos foi comprovada pelos resultados de microscopia óptica e potencial de superficie. Esses filmes mistos apresentaram valores de condutividade elétrica em tomo de 10-4 a 10-5 S.cm-1 (van der Pauw), tanto para a PANi quanto para o 16-mero. Investigou-se também o efeito da exposição dos filmes mistos PANi/CdSt aos raios-X. Nota-se um deslocamento para a região do vermelho, na região do visível, nos espectros de UVvis, similar à observada pela dopagem através de ácidos inorgânicos. Verificou-se que os efeitos de umidade da atmosfera de medida são predominantes nesse processo de dopagem. É feita uma análise dos resultados de condutividade elétrica, comparando-os com os encontrados na literatura.A study has been made of composite Langmuir and Langmuir-Blodgett (LB) films of polyaniline (PANi), and a polyaniline oligomer (l6-mer polyaniline), with cadmium stearate (CdSt). The monolayers studies pointed to a phase separated system containing the polymer (or the 16-mer) and CdSt, with no mixing at the molecular leveI, although the relative contents of PANi and 16-mer in the solution have a strong influence on the monolayer stability. UV-vis, FTIR, X-ray difIraction (XRD), electrical conductivity, ellipsometry, optical microscopy and surface potential measurements were used in the LB film characterization. UV-vis results have shown a uniform transfer, with the as deposited films in the undoped state. FTIR results confirmed the presence of CdSt and undoped polyaniline (and 16-mer) in the transferred LB films, corroborating the UV-vis results. XRD has shown separated domains of CdSt and PANi (l6-mer also) in the LB films. Ellipsometry data indicated a thickness of 25 Å per deposited layer. The high uniformity in these mixed LB films was confirmed by optical microscopy and surface potential measurements. The electrical conductivity was approximately 10-4 to 10-5 S.cm-1 for both PANi and 16-mer. Mixed PANi/CdSt films were also exposed to X-ray irradiation. After a given dose rate there is a red shift in the UV-vis spectra from the 600 nm region to the 800 nm region, similar to the usual acid doping process observed in polyaniline. Humidity effects have a strong influence on the doping process. A comparison is made of the conductivity measurements made here with those reported in the literature.
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Constantino, Carlos José Leopoldo. "Filmes de Langmuir e Langmuir-Blodgett de ligninas." Universidade de São Paulo, 1995. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-18062008-083333/.
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Filmes de Langmuir e Langmuir-Blodgett (LB) foram fabricados a partir de ligninas de bagaço de cana-de-açúcar e da Pinus caribaea hondurensis, extraídas via processo organossolve. Obteve-se nove tipos de lignina de pinus, sendo que cada uma foi extraída com um sol vente diferente, e seis tipos de lignina de cana, as quais passaram por um fracionamento, diminuindo sua polidispersividade. Os filmes de Langmuir foram fabricados sobre subfases de água ultrapura e caracterizados por medidas de pressão e potencial de superfície. Em todos os casos constatou-se a formação de agregados não monomoleculares quando o filme é comprimido além do ponto de colapso, o que é notado pela grande histerese na isoterma pressãoárea. Para ligninas de baixa massa molecular, estruturas estáveis não monomoleculares são formadas antes do colapso. No caso das ligninas menos polidispersas (cana), a massa molecular aumenta linearmente com a área molecular média da lignina. Monocamadas das ligninas de pinus e cana puderam ser transferidas para substratos de vidro, constituindo-se nos primeiros filmes de Langmuir-Blodgett destes materiais. Através do monitoramento da velocidade de imersão e retirada do substrato da subfase pode-se fabricar diferentes tipos de filmes LB, os quais podem ser do tipo Y com a deposição ocorrendo na imersão e retirada do substrato e também dos tipos X e Z se a deposição ocorre preferencialmente na imersão ou retirada do substrato, respectivamente. Os filmes LB foram caracterizados por medidas do potencial de superfície e elipsometria. O potencial de superfície para os filmes de pinus são positivos, enquanto que para os filmes de cana são negativos. Esta inversão de sinal foi surpreendente, pois para as monocamadas os valores de potencial são sempre positivos, tanto para as ligninas de cana como para as de pinus, embora sejam maiores no caso da pinus. A razão para esta inversão é uma contribuição negativa da interface filme/substrato que suplanta a contribuição positiva dos dipolos do filme de lignina de cana. Os dados elipsométricos revelaram que a lignina apresenta um arranjo tridimensional, com muitos espaços vazios e uma espessura em torno de 60 \'angstrom\' por camada.Langmuir monolayers and Langmuir-Blodgett (LB) films were fabricated from lignins extracted from Pinus caribaea hondurensis and sugar cane bagasse using the organosolv processo Nine types of pinus lignins were obtained by employing different solvents. The lignins of sugar cane bagasse were extracted using only one solvent but the material was fractioned into six fractions according to the molecular sizes. The resulting lignins were then less polydisperse than the pinus lignins. Langmuir monolayers were spread onto ultrapure water subphases and characterized by surface pressure and surface potential measurements. In all cases, non-monomolecular aggregates are formed when the monolayer is compressed beyond the collapse pressure, which is denoted by large hysteresis in pressurearea isotherms. For the low molecular weight lignins, stable multilayer structures are formed even before collapse. In the less polydisperse bagasse lignins, the average area per molecule increases linearly with the molecular weight. Monolayers from both pinus and bagasse lignins could be transferred onto glass substrates, thus forming the first ever reported Langmuir-Blodgett (LB) films of these materials. By controlling the dipping speed one can build-up different types of LB film which can be y-type with deposition occurring in both upstrokes and downstrokes and also Z or x-type if transfer occurs only in the upstrokes or downstrokes, respectively. The deposited LB films were characterized by surface potential and ellipsometric measurements. The surface potential of pinus films is positive whereas that of bagasse lignins is negative. This sign inversion was surprising since the monolayer surface potentials were always positive for all materials, even though they were higher for the Pinus lignins. The reason for the inversion is the negative contribution of the film/substrate interface which surpass the small, positive contribution from the dipole moments in the bagasse lignins. The ellipsometric data showed that the lignin molecules assume a three-dimensional arrangement, even within a single layer. The LB film appears to be a highly porous structure, with a thickness of 60 Á per layer.
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Evans, S. D. "Langmuir-Blodgett superlattices incorporating porphyrins." Thesis, Lancaster University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235169.
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Jones, Carole A. "Pyroelectricity in Langmuir-Blodgett films." Thesis, Durham University, 1987. http://etheses.dur.ac.uk/6784/.
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The fabrication of pyroelectric devices using the Langmuir-Blodgett (LB) technique is described. Studies of a wide range of materials are reported; however, the thesis concentrates on electrical and structural investigations of two specific alternate layer films: 22-tricosenoic acid/l-docosylamine and 22-tricosenoic acid/4-octadecylaniline. The latter system possesses a pyroelectric coefficient of 0.65 nCcm(^-2)K(^-1), representing the largest reported value, to date, for an LB film. The pyroelectric figure of merit (p/e(^1)(_T)) of such films is approximately 0.22 nCcm(^-2)K(^-1), which is comparable with the values for commercially available materials. The difference in pyroelectric coefficient of the two types of alternate layer film is attributed to differences in inter-layer bonding, as revealed by infrared spectroscopy. The dependence of the pyroelectric coefficients on parameters such as film thickness, substrate thickness and temperature is investigated. Structural studies, performed using electron and X-ray diffraction techniques, are also described. These provide information on the orientation of the molecules relative to the substrate and on the d-spacing of the LB films. It is shown that the substrate has a deleterious effect on the responsivity of LB film devices, and studies of films deposited onto different substrate materials indicate that there is a significant piezoelectric ally induced secondary effect contributing to the overall pyroelectric coefficient. This secondary effect is small at low temperatures, but becomes dominant at around 250 K. The results of thermally stimulated discharge experiments indicate that both free charges and dipolar groups are incorporated in the films during deposition, and become tightly bound within the polar structure.
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Christie, P. "Acentric Langmuir-Blodgett film assemblies." Thesis, Durham University, 1985. http://etheses.dur.ac.uk/7128/.
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In recent years there has been considerable interest In the use of Langmuir-Blodgett (LB) films as the basis of active and passive thin film devices. One such application is in room temperature, pyroelectric thermal imaging systems. As the detectivity of these sensors is approximately inversely proportional to thickness, there may be significant advantage in exploiting the ability of the LB process to produce ultra-thin layers. Here we report the use of the LB technique to fabricate molecular assemblies with precisely defined symmetry properties. This has made possible the construction of ultra-thin organic films possessing the spontaneous polarisation necessary for the observation of the pyroelectric effect. Two distinct approaches are adopted to produce the required molecular packing arrangements. The first uses the ability of a novel alternate layer trough to assemble acentric ABAB structures. Various materials are studied for their suitability for alternate layer deposition. The co-deposition of fatty acids and amines produces alternate layer assemblies with a high degree of structural and electrical integrity. The second approach uses a novel polymeric LB film. Polybutadiene (PBD) is observed to deposit in highly asymmetric X-type layers if the transferred monolayer is exposed to u.v. radiation between each deposition step. The structural and electrical properties are characterised. The presence of the unique polar axis associated with pyroelectric materials is investigated using surface potential measurements. Dynamic and quasi-static detection techniques are employed to detect the pyroelectric activity within the assemblies. For the first time pyroelectric activity is observed in "thin" (11 layer) acid/amine assemblies. The pyroelectric coefficient is found to be thickness dependent, increasing for larger numbers of layers; the coefficient for a 99 layer sample is comparable to that of PVDF, a commercially available pyroelectric polymer. The incorporation of LB films into thin PVDF Metal Insulator Metal (MIM) structures is also investigated. The presence of a stable phthalocyanine LB film is shown to increase the electrical breakdown strength of the device. Finally the incorporation of highly polarisable sulphur substitutions into fatty acid LB films is reported. The permittivity is found to increase in proportion to the number of sulphur atoms introduced into the hydrocarbon chain.
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Amiri, M. A. "Optically nonlinear Langmuir Blodgett films." Thesis, Cranfield University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.273468.
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Head, David Ian. "Two dimensional Langmuir-Blodgett magnets." Thesis, University of Southampton, 1988. https://eprints.soton.ac.uk/192469/.
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The susceptibility of quasi-two-dimensional magnets formed by the Langmuir-Blodgett deposition of manganese stearate on aluminium foil has been measured at several points between 20 K and 0.4 K. Large area samples of 101 and 11 layers were detected by a SQUID magnetometer. With the magnetic field parallel to the film we deduced an equivalent volume susceptibility of 6.4x10(-3) at 4.2 K. The signals from the multilayers were paramagnetic in nature and no evidence for a transition was found. Unfortunately the signal from a bilayer and monolayer were masked by contaminants on the substrate. The magnetometer used a cold finger to which the sample was attached. This was then moved into the pick-up coil, which was a second order gradiometer capable of cancelling out the signal from the long (150 mm) substrates. The magnetometer was usefully capable of detecting a sample with a moment down to 5x10(-11) Am(2) but vibration noise restricted the magnetic field to below 10 mT, New equations were developed to describe the magnetic signals from a cylindrical magnetised sample within a superconducting shield. They were developed for use on a micro-computer making it possible to simulate the signal from the sample. The tt-A curves for Manganese stearate were also studied. The uncertainty in the measurement of tx using filter papers was studied and estimated to be 2%. The manganese stearate was observed to transfer by Y and forced-Z type dipping.
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Romualdo, Torres Gemma. "Systèmes hybrides en films de Langmuir et Langmuir-Blodgett." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2002. http://tel.archives-ouvertes.fr/tel-00815388.
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Ce travail porte sur la formation et la caractérisation de nouveaux systèmes organiques-inorganiques par l'utilisation de films de Langmuir et de la technique de Langmuir-Blodgett. Plusieurs voies ont ainsi été explorées afin d'obtenir des films minces hybrides aux propriétés multiples, en particulier magnétiques. L'utilisation de l'interaction entre monocouches cationiques et des anions présents en sous-phase a ainsi permis l'organisation de différents polyanions inorganiques en structure lamellaire. Cette stratégie a ensuite été généralisée au cas de colloïdes de Bleu de Prusse, composés bimétalliques étendus. Une large étude (de la préparation à la caractérisation) a été consacrée à ces matériaux mixtes Bleu de Prusse-dérivé amphiphile de Ru(bpy)3 2+. Il a été également montré que la cristallisation du Bleu de Prusse et de ses analogues est favorisée en-dessous des films de Langmuir. Finalement, la coordination d'ions dissous en sous-phase avec des molécules amphiphiles à l'interface permet d'élaborer de nouveaux systèmes pouvant former des films LB, ce qui est notamment le cas d'agencements à base de cyanures métalliques.
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Constantino, Carlos José Leopoldo. "Filmes de Langmuir e Langmuir-Blodgett (LB) de ligninas." Universidade de São Paulo, 1999. http://www.teses.usp.br/teses/disponiveis/88/88131/tde-18112014-162235/.
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Filmes de Langmuir e Langmuir-Blodgett (LB) de ligninas extraídas do bagaço de cana-de-açúcar, via processo organossolve, foram fabricados. As isotermas de pressão revelaram uma área para a seção média da lignina em torno de 100 Å para a monocamada condensada, enquanto a modelagem a partir dos espectros elipsométricos indicou uma espessura por camada de cerca 60 Å para os filmes LB. Porém a deposição não se mostrou homogênea sobre toda a superfície do substrato como observado pelas medidas de microscopia de força atômica (AFM), de forma que filmes mais homogêneos foram obtidos a partir de uma solução mista de Iignina com estearato de cádmio. A área por molécula, calculada com base no número de moléculas de ácido esteárico sobre a subfase, aumenta com a quantidade de lignina na solução mista, indicando a presença de ambos os componentes também na monocamada. Os espectros de infravermelho com transformada de Fourier (FTIR) mostraram que tanto a lignina quanto o estearato de cádmio são transferidos e os espectros de ultravioleta visível (UV-vis) indicaram que esta deposição é homogênea até a 20ª camada. Os difratogramas de raios-X e as medidas de AFM mostram que a deposição de lignina e estearato de cádmio ocorre em domínios separados. As medidas de AFM revelaram ainda um aumento da rugosidade do filme com o aumento do número de camadas depositadas e com a maior irregularidade do substrato utilizado. Vale destacar que os filmes de lignina pura mostraram-se mais homogêneos que os filmes mistos, apesar da maior estabilidade destes sobre a subfase. A uniformidade macroscópica dos filmes LB foram confirmadas por medidas de potencial de superfície. Um estudo comparativo de filmes de Langmuir de ligninas extraídas por diferentes processos e de diferentes fontes (madeira mole, madeira dura e cana-de- açúcar) foi realizado. Destacou-se a importância dos grupos funcionais nas medidas de pressão e potencial de superfície, sendo que a área molecular média mostrou-se aumentar com a massa molar das ligninas em questão. A observação de uma inversão nos valores do potencial de superfície para filmes LB de lignina de cana e de pinus abriu caminho para uma investigação mais detalhada dos fatores que contribuem para o potencial de superfície dos filmes LB. Além da Iignina, filmes LB de polianilina e estearato de cádmio também foram estudados. Os resultados revelaram que os valores do potencial de superfície para estes filmes podem ser melhor compreendidos levando-se em consideração modelos teóricos que tratam tanto da contribuição dipolar das moléculas que constituem o filme como da contribuição da interface filme/substrato, a qual geralmente é negativa e se dá pela injeção de cargas. No caso dos filmes LB de estearato de cádmio o potencial é positivo para um número ímpar de camadas e negativo para um número parLangmuir monolayers and Langmuir-Blodgett (LB) films were produced from lignins extracted from sugar cane bagasse, via the organosolv process The surface pressure isotherms revealed an area per molecule of 100 Å for a condensed monolayer, and the modelling of ellipsometric data led to a thickness of 60 Å per layer for the LB films. The latter were not homogeneous, as demonstrated by atomic force microscopy (AFM) studies, and therefore mixed monolayers of Iignin and cadmium stearate were transferred with the aim of achieving more homogeneous films. The area per molecule, based on the number of stearic acid molecules on the airlwater interface, increased with the lignin contents in the mixed monolayers, thus confirming the presence of both components in the Langmuir monolayer. Fourier transform infra-red (FTIR) spectroscopy of LB films indicated that cadmium stearate as well as lignin were transferred onto the substrate. An equal amount of material was transferred in each deposition step, as demonstrated by the linear increase in UV-vis absorbance with the number of deposited layers up to the 20ª layer. Lignin and cadmium stearate are transferred in separate domains, which was indicated in X-ray diffraction measurements and AFM images. The latter also reveal that the roughness increases with the number of layers and may depend upon the substrate. Interestingly, films of pure lignin were more homogeneous than mixed films with cadmium searate, in spite of the higher stability and transterability of the mixed monolayers. Surface potential measurements showed a unitorm profile when the probe was scanned across an LB film, which may be taken as demonstration of uniformity at least at the macroscopic levei, though the film comprises domains and is usually rough for a molecular film. A comparative study was made ot monolayer characteristics for lignins obtained trom different sources and using different extracting procedures. The importance of functional groups was highlighted in these measurements, in which the area per molecule increased with the molecular weight ot the material. The observation that LB films from pinus and sugar cane bagasse exhibit surface potentials ot inverted sign has prompted us to investigate the possible contributions to such surface potentials. In addition to Iignins, in this study cadmium stearate and polyaniline LB films were also used. The overall conclusion was that the surface potential depends on the dipole moment of the monolayer-torming molecules, but is also affected substantially by the contribution from the substrate/film interface. The latter arises from charge injection from the electrode and is generally negative. For simple cadmium stearate LB films, the surface potential is positive for an odd number of layers, but negative for even numbers, since the dipole contribution is cancelled out
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Davis, Frank. "Langmuir-Blodgett films of preformed copolymers." Thesis, Lancaster University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306423.
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Burrows, P. E. "Electron Transport in Langmuir-Blodgett films." Thesis, Queen Mary, University of London, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.531005.
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Thomas, Nicholas John. "GaAs/Langmuir-Blodgett film MIS devices." Thesis, Durham University, 1986. http://etheses.dur.ac.uk/6829/.
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Langmuir-Blodgett (LB) films have previously been used as organic insulating layers in compound semiconductor metal-insulator- semiconductor devices, with promising preliminary results. This thesis describes the first investigation of the use of LB films In gallium arsenide metal-insulator-semiconductor devices. Diodes incorporating thin layers of w-tricosenoic acid or substituted copper phthalocyanine possessed 'leaky' electrical characteristics, i.e. there is some conduction through the LB film. This 'leaky' behaviour was exploited to produce the first metal- Insulator-semiconductor-switch (MISS) incorporating an LB film. MISS devices on n-p(^+) GaAs were produced with good switching characteristics and a high yield (~90%), using LB film thicknesses between 9 and 33 nm. It was shown that the 'punch through' mechanism was responsible for the switching behaviour. p-n(^+) GaAs/LB film MISS diodes behaved rather differently, with good switching characteristics only found at reduced temperature. Some degradation of the characteristics of LB film MISS devices was noted, although this was reduced by using the more robust phthalocyanlne LB films. Metal-tunnel-insulator-semiconductor diodes were produced on the ternary alloy Ga(_.47)In(_.53)As, using LB film monolayers. The barrier height was apparently larger than that of Schottky barriers on this material, with a very substantial reduction in current density due to tunnelling through the LB film. Using this technique it may be possible to produce very high performance GaInAs fleld-effect-transistors, which are analogous to GaAs metal-semiconductor field effect transistors.
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Cresswell, J. P. "Waveguiding in electrooptic Langmuir-Blodgett films." Thesis, Durham University, 1992. http://etheses.dur.ac.uk/6142/.
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This thesis describes work on the waveguiding and second-order nonlinear optics of Langmuir-Blodgett (LB) films. A number of new monomeric materials are assessed for their LB deposition and their second-order nonlinear properties. Both the Pockels effect and second harmonic generation are studied. One new chromophore, diphenyl butadiyne is shown to possess exceptional nonlinear effects in monolayer form with x((^2))(-w; w, 0) = 2.7 x 10(^-10) mV(^-1) A novel aminonitrostilbene carboxylic acid with x((^2))(-w;w,0) = 1.43 x 10(^-10) m V(^-1) is also described. Polymeric LB materials have been found to possess greater stability than monomers but the deposition properties are often poor. Two oligomers are investigated, these both form high-quality LB layers and one gave X((^2))(-w;w,0) = (3.4-1-1.0j) x 10(^-11) m V(^-1). Two alternate-layer systems are considered. The first, of an amidonitrostilbene and a novel functionalised diarylalkyne deposits to 150 bilayers, but the nonlinear coefficients are shown to diminish after fewer than ten layers. X-ray diffraction, waveguiding and Fourier transform infra-red measurements are also performed. The second system alternates the two oligomers; only films of fewer than seven layer are studied due to the low value of Pockels effect and second-harmonic generation detected. A novel method of waveguide fabrication combining solution dipped polymer layers with LB films is introduced. This technique allows the rapid fabrication of waveguides with nonlinear properties. Monomode waveguides are produced and their electrooptic properties measured. These are the first such measurements on an LB film waveguide. It is shown theoretically that such waveguides could be used to produce modulators of similar figures of merit to those made from poled-polymers but that an order of magnitude improvement in X((^2))(-w; w, 0) is needed to match lithium niobate systems.
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Green, Christopher A. "Covalent immobilisation of Langmuir-Blodgett films." Thesis, University of Salford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386420.
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Fernandes, Anwesha Nahavita. "Langmuir-Blodgett films of functional nanomaterials." Thesis, University of Sheffield, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.442969.
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Kim, Kwang Soo. "Computer simulation of Langmuir-Blodgett films." Thesis, University of Southampton, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358629.
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Oliveira, Junior Osvaldo Novais de. "Electrical properties of Langmuir monolayers and deposited Langmuir-Blodgett films." Thesis, Bangor University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.236716.
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Cruz, Cláudia Bonardi Kniphoff da. "Potencial de superfície de filmes de Langmuir e Langmuir-Blodgett." Universidade de São Paulo, 1995. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-15052009-120635/.
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Resultados antigos de potencial de superfície de filmes de Langmuir não eram reprodutíveis, devido B presença de impurezas na subfase aquosa sobre a qual os filmes se formavam. Dados recentes para o ácido esteárico, no entanto, mostram um comportamento reprodutível Neste trabalho, foi promovida com sucesso uma recaracterização através de medidas de pressão de superfície (II) e potencial de superfície (ΔV) de compostos alifáticos simples (álcoois, ésteres, ácido e amina), obtidos sobre subfases devidamente purificadas. Os resultados obtidos são inéditos e mostram que o potencial de superfície desses filmes é nulo para grandes valores de área molecular média (A), aumentando a partir de um valor de área crítico, Acr, até atingir um valor máximo, ΔVmax. Modelos para o potencial de superfície de filmes de Langmuir mostram boa concordância com os resultados obtidos. As curvas de pressão e potencial de superfície para os álcoois e ésteres praticamente não se modificam pela alteração do pH da subfase na faixa de 1 a 13. Porém para a amina e ácido há grandes alterações, principalmente nas curvas de potencial de superfície, em virtude da contribuição da dupla camada elétrica. Foram produzidos, também, filmes de Langmuir-Blodgett (LB) a partir de monocamadas de ácido esteárico que foram caracterizados através de medidas de potencial de superfície, com o objetivo de comprovar a importância da contribuição dipolar para o potencial desses filmes. Os resultados indicam que além da contribuição dipolar, há uma contribuição negativa (em tomo de -200 mV) da interface substrato/filme. O potencial de superfície se confirma como uma técnica de caracterização bastante sensível, tanto para filmes de Langmuir como para filmes LB.Old surface potential data in the literature were not reproducible, because of impurities in the aqueous subphase where the monolayers were formed. Recent data for stearic acid, however, show a reproducible behavior. In this work, a recharacterization of surface presssure (II) and surface potential (ΔV) for Langmuir monolayers of simple aliphatic compounds (alcohols, esters, acid and amine), fabricated over conveniently pure subphases, were successfully carried out. These new results show that the surface potential is zero for large areas per molecule and only increased below a critical area per molecule, Acr. Surface potential models for Langmuir films are in good agreement with the data obtained. There is almost no change in the surface pressure and surface potential for alcohols and esters for a subphase pH range of 1 to 13. However, for amine and acid large changes are observed, mainly in the surface potential curves, because of the electric double layer contribution Langmuir-Blodgett (LB) films were deposited from stearic acid monolayers. They were characterized by surface potential measurements in order to confirm the importance of the contribution from dipole moments of the film-forming molecules. The results also point towards a negative contribution (around - 200 mV) due to the film/substrate interface. The surface potential technique has been demonstrated to be a very sensitive characterization technique for Langmuir monolayers as well as for LB films.
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Shih, Raymond Chuan-Cheng. "The characterization of diacetylene acid Langmuir film and Langmuir-Blodgett film." Case Western Reserve University School of Graduate Studies / OhioLINK, 1994. http://rave.ohiolink.edu/etdc/view?acc_num=case1061473845.
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Erdelen, C., André Laschewsky, H. Ringsdorf, J. Schneider, and A. Schuster. "Thermal behaviour of polymeric Langmuir-Blodgett multilayers." Universität Potsdam, 1989. http://opus.kobv.de/ubp/volltexte/2008/1737/.
Full textAbstract:
Langmuir-Blodgett multilayers of hydrocarbon and fluorocarbon polymers with hydrophilic spacer, lipid-polyelectrolyte complexes and mesogenic polymers have been prepared. The thermal behaviour of the multilayers was studied by small angle X-ray scattering, IR and UV—visible spectroscopy. Good thermal stabilities were found for the various classes of polymers. In addition, for both complexed multilayers and mesogenic polymer films, reorientation processes were observed.
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Portus, Dan. "Langmuir-Blodgett films of porphyrins and phthalocyanines." Thesis, Cranfield University, 2002. http://hdl.handle.net/1826/3372.
Full textAbstract:
Phthalocyanines and porphyrins have been studied for many years as bulk, thick
and thin films. Their use in Langmuir and Langmuir-Blodgett films is governed their peripheral substituents. These can enhance or reduce their ability to form "quality"
ultra-thin films.
There are a number of potential and current applications for thin films porphyrins and phthalocyanines, which include CD-R discs and gas-sensors. It is latter that this PhD has focussed on.
Ultra-thin films of phthalocyanines, porphyrins and a porphyrin/phthalocyanine
hybrid dye were deposited onto glass microscope slides, gold-coated glass microscope
slides and quartz crystals. These assemblies were then characterised using Ultraviolet-
Visible spectroscopy, pressure-area isotherms, surface plasmon resonance and a quartz
crystal microbalance to try and determine the nature of the molecules on the surface the substrate. The thin films were exposed to chlorine gas and the change in their
absorption spectrum and (in some cases) their surface plasmon resonance curve monitored.
A short series of phthalocyanines showed that the central metal atom can play important role in the orientation of the macrocycles - with copper adopting an edge-configuration, zinc, face-down and metal-free, random. This in turn affected sensitivity of the gas-sensor with the facedown orientation offering a significantly
greater response than the other two.
A series of substituted tetraphenylporphyrins also illustrated that the sensitivity of the dye molecules is dependent on the orientation and spacing of molecules in the film. Generally the response to the chlorine was quite low, but porphyrin (stearamido) demonstrated a 2"d order decay in the absorbance due to oxidation of the macrocycle, the time constants being 31 and 425 seconds for surface and bulk diffusion responses respectively.
The use of differentiation on the Pressure-Area Isotherms of the deposited
Langmuir-Blodgett films is a new concept developed in this thesis. It proved a useful
tool for looking at the effect of the quality of the film on the gas sensitivity.
23
Travers, Paul James. "Langmuir-blodgett films for second harmonic generation." Thesis, Coventry University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254209.
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Holcroft, B. "Novel electronic devices incorporating Langmuir-Blodgett films." Thesis, University of Oxford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235171.
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Kalita, N. "The Pockels' effect in Langmuir-Blodgett films." Thesis, Durham University, 1991. http://etheses.dur.ac.uk/6072/.
Full textAbstract:
Simple, compact and inexpensive automated apparatus for recording surface plasmon resonance and the Pockels (or linear electro-optic) effect in Langmuir-Blodgett films has been used to estimate the thickness, permittivity and second order non linear susceptibility X(^(2))(_xxx)(-w;w,0) of several novel Langmuir-Blodgett film-forming materials. The results agree with estimates of nonlinear susceptibility obtained by second-harmonic generation. The materials synthesised at Durham were all functionalised diaryl alkynes of the general formula CH(_3)(CH(_2))(_n)(Py(^+))C=C(Ph-R), wherein n =17 or 21 and R=H or OCH(_3). Of these, that with n =21 and R=OCH(_3) showed particularly promising Langmuir-Blodgett film-forming properties; its nonlinear susceptibility per mono layer, however, was approximately one hundredth that of a hemicyanine monolayer. The nonlinear susceptibility per monolayer, as measured by the Pockels effect and second harmonic generation, was inversely proportional to the square root of the film thickness. This indicated rapid deterioration of in-plane order with increasing film thickness. Several novel polymeric materials synthesised at Hull and examined at Durham consisted of a siloxane spine of approximately 16 Si atoms, with randomly substituted bipolar chromophoric sidegroups. All were highly stable in floating film form. Of them, one known as AMCR23 showed promising optical nonlinearity when deposited on silver: a nonlinear susceptibility of-15+9.6i pm V(^-1) was recorded for a monolayer (cf. 94.5+49.9i pm V(^-1) for a hemicyanine monolayer).
26
Neal, D. B. "Langmuir-Blodgett films for non-linear optics." Thesis, Durham University, 1987. http://etheses.dur.ac.uk/9527/.
Full textAbstract:
In recent years there has been considerable interest in media which display significant non-linear optical properties; the telecommunications industry may exploit chin films of such materials for signal processing applications. The Langmuir-Blodgett (LB) technique provides a means of depositing organic layers of a precisely defined thickness. Moreover, by alternating layers of different materials, supermolecular arrays may be fabricated in which there is no centrosymmetry, and therefore the second-order non-linearity of the constituent molecules may be exploited. An investigation of the properties of water-surface monolayers of a number of novel materials with potentially large non-linearities is described. Several of these compounds are shown to form high quality homogeneous or heterogeneous LB films. The optical and electrical properties of the layers are characterized by optical absorption spectroscopy, surface plasmon resonance, and measurements of capacitance, whilst their structure is examined by electron diffraction. Monolayers of a nitrostilbene dye are shown to exhibit: on exceptionally high degree of crystalline order. Data are also given for theoretical calculations of non-linear coefficients and for the relative efficiency of second harmonic generation from bulk samples of various materials. Studies of second harmonic generation from monolayer and alternate multilayer films are reported. Optical non-linearity in an alternating donor-acceptor: inverted donor-acceptor dye system is demonstrated for the first time; the results are analysed in terms of second harmonic surface susceptibilities, and the value of the second-order hyperpolarizability determined for the first bilayer is found to be much superior to that expected by the simple addition of the hyperpolarizabilities of the separate layers. Monolayers containing a mixture of hemicyanine and cadmium arachldate are found to give rise to second harmonic generation which is enhanced relative to that obtained from a pure monolayer of the dye. Corresponding changes in the absorption spectra of the layers can be observed. These findings may have important implications for improving the efficiencies of any non-linear optical device which utilises IB films.
27
Simmons, John M. "Langmuir-Blodgett films of some novel phthalocyanines." Thesis, University of East Anglia, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280973.
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Darby, John Edward. "Semiconducting Langmuir-Blodgett films as gas sensors." Thesis, University of Kent, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293551.
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Hao, Shuang. "Josephson tunnel junctions using Langmuir-Blodgett films." Thesis, University of Southampton, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.252717.
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Leeson, Paul. "Langmuir-Blodgett films for second harmonic generation." Thesis, Cranfield University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323931.
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Barrell, K. J. "The Langmuir-Blodgett films of conjugated pigments." Thesis, University of the West of England, Bristol, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234286.
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Júnior, Antonio Riul. "Filmes de Langmuir e Langmuir-Blodgett de polianilina processada com ácidos funcionalizados." Universidade de São Paulo, 1995. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-08112013-151141/.
Full textAbstract:
Filmes de Langmuir e Langmuir-Blodgett (LB) foram produzidos a partir da polianilina não substituída, que se tornou processável e solúvel em clorofórmio apos ser dopada com ácidos funcionalizados. Para atingir condições otimizadas de formação e deposição dos filmes, foi realizado um estudo criterioso empregando vários ácidos funcionalizados: canfor sulfônico (CSA), dodecilbenzeno sulfônico (DBSA) e tolueno sulfônico (TSA); e também os solventes e plastificantes N-metilpirrolidinona (NMP) e m-cresol. Soluções de polianilina de alta massa molar processada com estes ácidos foram depositadas sobre subfases aquosas ácidas (pH = 2), formando os chamados filmes monomoleculares de Langmuir. Através de um estudo dos parâmetros que influenciam a formação dos filmes de Langmuir conseguimos obter monocamadas estáveis. Desta forma os filmes puderam ser transferidos para substratos sólidos (vidro bk7), usando a técnica de Langmuir-Blodgett. Os filmes LB produzidos são do tipo Z, ou seja, a deposição só é bem sucedida na retirada do substrato, o que significa que mesmo no filme de Langmuir alguns grupos hidrofílicos se encontravam na interface filme/ar. Os filmes LB foram caracterizados por espectroscopia de UV-vis., medidas de condutividade usando o método de quatro pontas, voltametria cíclica e medidas do potencial de superfície. Os filmes LB apresentam propriedades óticas e eletroativas semelhantes as dos filmes de polianilina fabricados por centrifugação. A absorbância da banda polarônica aumenta linearmente com o número de camadas depositadas, o que demonstra que cada camada contribui com a mesma quantidade de material para o filme. A condutividade dos filmes e da ordem de 10-4 S/cm, inferior aos valores medidos para filmes obtidos por centrifugação de soluções de polianilina com CSA e DBSA, mas é maior do que a de alguns outros filmes LB de polianilina relatados na literaturaLangmuir-Blodgett (LB) films were fabricated from parent polyaniline (PANI), which was made soluble in chloroform by being doped with functionalized acids. Optimized conditions for LB film deposition were only reached after a systematic processability study in which use was made of camphor sulfonic acid (CSA), dodecylbenzene sulfonic acid (DBSA), toluene sulfonic acid (TSA) and of N-methyl pyrrolidinone (NMP) and m-cresol as plasticizers. Solutions of high molecular weight PANI were spread on acidic, aqueous subphases (pH = 2), thus forming the so-called Langmuir monolayer. These monolayer were transferred onto solid substrates (bk7 glass) in the form of Z-type films, i.e. deposition was successful only in the upstrokes. This means that hydrophilic groups must protrude from the water surface in the Langmuir film. The LB films were characterized using UV-vis spectroscopy, cyclic voltammeter, surface potential and conductivity measurements. The optical and electroactive properties of the deposited LB films were essentially the same as those obtained with spin-coated PANI films. The absorbance of the polaronic peak increases linearly with the number of deposited layers, demonstrating that each layer contributed an equal amount of material to the LB film. The films conductivity was of the order of 10-4 S/cm, which is below the values of spin coated PANI films processed with CSA or DBSA, but higher than some published values for LB films from polyaniline
33
Tanazefti, Kaïs. "Caractérisation de films de Langmuir et de Langmuir-Blodgett de molécules mésogènes." Paris 5, 1998. http://www.theses.fr/1998PA055020.
Full textAbstract:
Notre travail concerne l'étude des modes d'organisation de molécules mésogenes de conformation bolique ayant un cœur central hydrophobe, forme de trois ou quatre noyaux phenyls, auquel sont attachées de longues chaines hydrocarbonées. La flexibilité du cœur des molécules et la longueur des chaines peuvent être modifiées. L'objectif de notre étude est de comparer l'arrangement moléculaire entre les phases à deux dimensions et les phases trois dimensions. Les composes mésogenes étudiés s'étalent spontanément a la surface de l'eau sous forme de films appelés films de langmuir. La première partie de ce travail est relative à l'analyse des différents modes d'organisation de films de langmuir de ces composes. Plusieurs techniques ont été utilisées pour caractériser leur structure. Les différents états du film ont d'abord été étudiés par une méthode thermique (balance de langmuir). Différentes transitions de phases du premier ordre ont été ainsi mises en évidence. La structure du film, à l'échelle macroscopique a été ensuite déterminée par un dispositif d'imagerie de fluorescence. L'orientation des molécules à l'interface air-eau, a été déterminée par la mesure de courant de déplacement sensible à l'orientation des moments dipolaires permanents des molécules. La structure du film, a la fin de la transition principale, a ensuite été déterminée par diffraction des rayons x (rx) en incidence rasante, au lure, a Orsay. Nous avons ainsi interprété l'ordre observe, comme un arrangement rectangulaire des chaines latérales, les paramètres de la maille étant a = 5,32 a et b = 4,72 a. La seconde partie de notre travail concerne l'étude des mêmes composes bolique déposés sur un substrat solide sous forme de monocouches appelées films de langmuir-blodgett. Le dépôt de ces films sur un verre amorphe, par la technique de langmuir-blodgett (lb), a été réalisé avec succès. Le taux de transfert, voisin de l'unité, montre que l'arrangement moléculaire dans la monocouche déposée sur substrat solide est le même qu'à la surface de l'eau. L'analyse de la topographie de la monocouche de langmuir-blodgett a été effectuée par microscopie a force atomique (afm) au laboratoire dibe (université de Gènes, Italie). L'étude de la monocouche a été réalisée de l'échelle du micron à l'échelle du nanomètre. Les images obtenues confirment les résultats déduits des autres méthodes. Elles mettent en évidence l'arrangement colonnaire du cœur des molécules boliques, l'orientation vers l'air des chaines latérales et leur arrangement dans un réseau rectangulaire régulier.
34
Römer, Daniel Urs. "Monolayer und Langmuir-Blodgett Filme von röhrenförmigen Oligopeptiden /." [S.l.] : [s.n.], 1994. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=10835.
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Laschewsky, André, and H. Ringsdorf. "Polymerization of amphiphilic dienes in Langmuir-Blodgett multilayers." Universität Potsdam, 1988. http://opus.kobv.de/ubp/volltexte/2008/1717/.
Full textAbstract:
Amphiphilic derivatives of octadiene and docosadiene were investigated in monolayers and Langmuir-Blodgett multilayers, with respect to their self-organization and their polymerization behavior. All amphiphiles investigated form monolayers. However, only acid and alcohol derivatives were able to build up multilayers. Those multilayers are rapidly photopolymerized in the layers via a two-step process: Irradiation with long-wavelength UV light yields soluble polymers, whereas additional irradiation with sfiort-wavelength
UV light produces insoluble and presumably cross-linked polymers. The reaction meclianism is discussed according to the polymer characterization by UV spectroscopy, small-angle X-ray scattering, NMR spectroscopy, and gel permeation chromatography. All multilayers undergo structural changes during the polymerization; substantial changes result in defects in the polymerized layers as observed by scanning electron microscopy.
In contrast to the acids and alcohols, the deposition of monolayers of the aldehyde derivatives did not yield well-ordered multilayers, but rather amorphous films. In this different film structure, the photopolymerization
process differs from the one observed in multilayers.
36
Embs, Frank, Dirk Funhoff, André Laschewsky, Ulrike Licht, Holger Ohst, Werner Prass, Helmut Ringsdorf, Gerhard Wegner, and Rolf Wehrmann. "Preformed polymers for Langmuir-Blodgett films- molecular concepts." Universität Potsdam, 1991. http://opus.kobv.de/ubp/volltexte/2008/1719/.
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The use of preformed polymers for the preparation of Langmuir-Blodgett (LB) multilayers is reviewed. Principles for polymer self-organization are outlined and the appropriate molecular designs are discussed. Recent developments in the different classes of polymers for LB multilayers are presented, and their outstanding properties highlighted.
37
McQuillan, Scott. "Electromagnetic waves in Langmuir Blodgett thin film microstructures." Thesis, Queen Mary, University of London, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271335.
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Young, C. J. "Gas sensitivity of Langmuir-Blodgett films of porphyrins." Thesis, Lancaster University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.371069.
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Parry, David A. "Optical gas sensing using Langmuir-Blodgett thin films." Thesis, Coventry University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241840.
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Stone, Peter Jeffrey William. "Langmuir-Blodgett films for non-linear optical applications." Thesis, Coventry University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.259613.
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Howarth, Vaughan Antony. "A study of Langmuir-Blodgett films of valinomycin." Thesis, Durham University, 1989. http://etheses.dur.ac.uk/6518/.
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The deposition and characterisation of Langmuir-Blodgett (LB) films containing the ionophore valinomycin are described. In particular, the thesis concentrates on two specific mixed LB systems incorporating the ionophore, namely, arachidic acid/valinomycin and L-a-phosphatidic acid dipalmitoyl (DPPA)/valinomycin. The extremely sensitive spectroscopic technique of attenuated total reflection (ATR) Fourier transform infrared (FTRIR) spectroscopy is used to investigate the interaction of these ultra-thin LB structures with aqueous solutions containing potassium ions. It is shown that LB layers of pure valinomycin do not complex with potassium ions and that, in order for complexation to occur, the ionophore must be mixed with a secondary component. The formation of the valinomycin-potassium (VM/K(^+)) complex in the arachidic acid/vahnomycin system is demonstrated and the effects of the mole-fraction of arachidic acid, and of the potassium ion concentration upon complexation are described. The IR studies also reveal profound structural changes in the fatty acid matrix upon complexation, and the important result that dissociation of the VM/K(^+) complex does not occur in this mixed system. However, it is shown that if the fatty acid molecule is replaced by the phosphohpid molecule, DPPA, then both formation and dissociation of the complex occur. The results, however, indicate that this system is unstable with loss of the LB film into the aqueous solution during immersion. A number of attempts to eliminate this problem are described. The fabrication and characterisation of ion-selective-field-effect transistors (IS-FETs) are also reported. One of the aims of the research is to develop a potassium- ion sensor, and with this in mind, the deposition of LB films onto the gate surface of the ISFET is demonstrated. The K(^+)-response of the LB film coated devices is described and the results interpreted in terms of the IR evidence.
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Fowler, M. T. "Optical and photoelectrical applications of Langmuir Blodgett films." Thesis, Durham University, 1985. http://etheses.dur.ac.uk/7116/.
Full textAbstract:
The Langmuir-Blodgett (LB) technique is well known for the deposition of thin, uniform films of precisely defined thickness. These films can he used in electronic devices as an active layer, or in a passive role as insulators. Results are presented of investigations using films of both types. Novel LB films of a merocyanine dye have been developed for use as a spectral sensitiser, and films of phthalocyanine used as insulators for the enhancement of the electroluminescent (EL) properties of a metal-semiconductor structure. The merocyanine dye used has none of the clear amphiphilic molecular substitutions associated with classical LB film materials, but behaves well as a Langmuir film. Incorporated into a matrix of cadmium arachidate the dye can be deposited onto various substrates using the LB technique. The optical properties of such deposited films are characterised and coipared with those of a merocyanine dye featuring anphiphilic substitutions. For both dyes these properties indicate that good quality LB films have been deposited, and that some dimeric structure is present in these films. The feasibility of using these films for the spectral sensitisation of semiconductors is demonstrated by their modifying effect on the photoconductive response of polycrystalline zinc sulphide. The incorporation of LB films of phthalocyanine into the gold/ZnSeS system enables low voltage forward bias d.c EL to be observed with a threshold ~1V. Measurement of the increase in intensity of emitted EL with bias suggests that the presence of the insulating layer increases the minority current available for radiative recombination by supporting realignment of energy bands in the metal and semiconductor. EL efficiency of devices is shown to increase with insulator thickness up to ten deposited layers of phthalocyanine a thickness of ~23nm. A simple energy band model for the system is proposed which takes into account series resistance effects.
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Baker, S. "Phthalocyanine Langmuir-Blodgett films and their associated devices." Thesis, Durham University, 1985. http://etheses.dur.ac.uk/7589/.
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Interest in the Langmuir-Blodgett (LB) technique has led to a number of investigations into different types of materials that can be deposited in the form of monolayers. For example, as well as the classic long Cham fatty acids and alcohols, materials such as polymerisable molecules, aromatic hydrocarbons and dye substances can now all be produced in monomolecular form. Unfortunately, few of these materials yet fulfil the requirements of mechanical and thermal stability that will be necessary if LB films are to be used commercially. This work has dealt with the use of phthalocyanine, a substance well known for its thermal and chemical stability, in the production of LB films. Initially two compounds were investigated, dilithlum phthalocyanine and tetra-tert-butyl phthalocyanine. Although it was found that both materials produced layers of reproducible quality which adhered tenaciously to various substrates and to each other, single monolayers were not obtained. More success has been achieved using an asymmetrically substituted phthalocyanine molecule. Electron microscopy studies have shown that the majority of films are polycrystalline. However, a substitute CuPc proved to be a valuable exception. Multilayer films of this molecule were found to have domains of the order of 3 mm in size showing a preferred orientation. Even so, it has to be accepted that the phthalocyanine films produced to date are not as structurally perfect as for example, multilayers of lo-tricosenoic acid. Our ability to produce monomolecular layers of phthalocyanine now extends the range of possible applications for this material. For instance it is known that the fine control of insulator thickness is crucial in the optimisation of photovoltaic and electroluminescent metal-lnsulator-semlconductor devices. Examples of both types of device have been demonstrated using our phthalocyaine films. For the bistable switch, a gallium arsenide substrate was used; both gallium phosphide and zinc selenlde have been utilized in the electroluminescent structures. Moreover, In the case of phthalocyanine another possibility presents Itself. It has long been known that the conductivities of this material and its derivatives are very sensitive to the presence of certain gases, particularly the oxides of nitrogen. The increased conductivity of such materials has been demonstrated to be confined to the surface of the crystal. Hence many phthalocyanine gas detector systems have been based on thin films. Unfortunately because phthalocyanine exhibits polymorphism, the exact structure of such films can be complicated. making interpretation of results and subsequent device optimisation difficult. Also the response and recovery times of these thin film devices can also be excessively long. It is possible that monomolecular LB films of phthalocyanine could well overcome some or all of these problems. Our experiments have concentrated on asymmetrically substituted copper phthalocyanine and its usefulness to detect nitrogen dioxide. Preliminary results show the response and recovery times for the simple gas structures to be faster than those previously reported for other thin film phthalocyanine devices. It is suggested that this is due to the more ordered structure of the LB film, which enables the gas to adsorb on, or desorb from the molecular sites more readily.
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Pearson, C. "Langmuir-Blodgett films of organic charge-transfer complexes." Thesis, Durham University, 1996. http://etheses.dur.ac.uk/5390/.
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This thesis is concerned with the preparation of floating films of electrically conductive organic charge-transfer complexes and their subsequent transfer to solid substrates by the Langmuir-Blodgett (LB) technique. Characterisation of the morphology (using ellipsometry, surface profiling, optical and scanning electron microscopy, energy dispersive spectroscopy and optical absorption spectroscopy) and electrical properties (at room temperature and low temperature) of the resulting multilayer structures is discussed. Three different systems were investigated: (i) mixed films containing the long chain tetrathiafulvalene (TTF) derivative octadecanoyl-TTF (ODTTF) and either octadecanoic acid (OA) or pentacosa-10,12-diynoic acid (PA); (ii) pure films of the charge-transfer complex Ν-octadecylpyridiniura-bis-(4,5-dimercapto-1,3-dithiole-2- thione) palladium (Ci8Py-Pd(dmit)2); and (iii) pure films of the charge-transfer complex N-octadecylpyridinium-bis-(4,5-dimercapto-1,3-dithiole-2-thione) nickel (CigPy- Ni(dmit)2). Some interesting electrical properties were observed in these films. Also, Ci8Py-Ni(dmit)2 has been incorporated as the active layer in a thin film field effect transistor structure. Carrier mobility values of 1.9 ± 0.5 x l0(^-5) cm(^2) V(^-1) S(^-1) and 0.3 ± 0.1 cm(^2) V(^-1) s-(^-1) were calculated from the device characteristics, before and after doping with iodine, respectively In the case of films containing ODTTF, a maximum room temperature in-plane dc conductivity after iodine doping of 2±lxl0(^-2) S cm(^-1) was recorded. This conductivity was found to be strongly dependent on the molar ratio of the two components present in the film. The behaviour has been explained using two-site percolation models. For C(_18)Py-Pd(dmit)(_2) and C(_18)Py-Ni(dmit)(_2), the properties of the floating layers and transferred films were found to be influenced by the exact experimental conditions. Ci8Py-Pd(dmit)(_2) films were conductive as deposited, with a stable maximum room temperature in-plane dc conductivity value of 1.5±1.0xl0(^-l) S cm(^-1). C(_18)Py-Ni(dmit)(_2) samples became conductive after exposure to iodine vapour, with a stable peak conductivity value of 1.3±0.8 x10(^-1)S cm(^-1).
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Junior, David Sotero dos Santos. "Filmes automontados e Langmuir-Blodgett de compostos azoaromáticos." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/88/88131/tde-25112014-164211/.
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Nesta tese foi explorado o controle de arquitetura molecular pelo uso das técnicas de Langmuir-Blodgett (LB) e automontagem (LBL) para produzir filmes nanoestruturados de azopolímeros e azocorantes de baixa massa molecular. A primeira contribuição foi a síntese química de azopolímeros, nos quais os grupos azo são ligados covalentemente a uma cadeia polimérica. Para produção de filmes LBL, que requer compostos solúveis em água, fez-se a sulfonação do PAZO (poli(p-azofenileno)) resultando no PAZOS (poli(p-azofenileno sulfonado)). Este azopolímero conjugado apresentou luminescência em solução, confirmando cálculos teóricos, mas não em filmes LBL com poli(alilamina) (PAH). Os filmes LBL são condutores elétricos quando dopados com iodo e têm propriedades de birrefringência opticamente induzida. A fotoindução da birrefringência com laser linearmente polarizado foi muito lenta, com tempos consideravelmente maiores que em outros filmes LBL, devido não só às interações eletrostáticas, mas também à rigidez da cadeia conjugada. Outro polímero sintetizado foi o DR19CL-IPDI, que é solúvel em clorofórmio e foi utilizado para fabricação de filmes de Langmuir e LB. Os filmes LB só puderam ser produzidos utilizando a estratégia de co-espalhamento com estearato de cádmio (CdSt). Os experimentos de birrefringência opticamente induzida indicaram que os filmes LB de DR19CL-IPDI/CdSt têm maior birrefringência que os outros azopolímeros derivados de poliuretanos, pois o seu máximo de absorbância coincide com o comprimento de onda do laser de escrita. Por outro lado, a birrefringência residual, após desligamento do laser, foi menor que em sistemas similares porque a relaxação do azocromóforo é facilitada devido a este polímero possuir menor temperatura de transição vítrea. Ainda com filmes de Langmuir, utilizamos a espectroscopia de UV-VI in situ para analisar os filmes de HPDR13 (poli 4\'-2-(metacriloiloxi)etiletilamino -2-cloro- 4-nitroazobenzeno)). Em acordo com as isotermas de pressão de superfície, os resultados indicaram que com maiores temperaturas de subfase, as cadeias de HPDR 13 ganham flexibilidade e são mais bem empacotadas, ocupando menor área por molécula. A importância do controle da arquitetura molecular foi demonstrada no estudo da birrefringência fotoinduzida e formação de grades de relevo de superfície (SRG) nos filmes LBL de azocorantes com quitosana e em filmes do azopolímero PS119 com dendrímeros DAB (Polipropilenimina). Os filmes LBL de quitosana com o corante SunsetYellow (SY) possuem birrefringência espontânea devida a uma organização molecular proveniente da técnica de automontagem. Para os filmes Ponceau S (PS), a birrefringência pode ser fotoinduzida e a dinâmica depende do pH utilizado na fabricação do filme, devido a alterações nas interações intermoleculares. A estrutura interna do filme LBL de dendrímero DAB teve grande efeito na adsorção de PS119, que aumentou com a geração, de 1 para 5. A maior adsorção do dendrímero G5 foi atribuída ao maior número de sítios ionizados para interagir com os azocromóforos do PS119. Entretanto, a birrefringência fotoinduzida foi maior para os filmes LBL com dendrímeros de menor geração, pois os filmes de geração maior apresentam maior interpenetração entre as camadas. Esta restringe a mobilidade dos cromóforos, gerando menor birrefringência. Esta explicação foi corroborada pela observação de maiores amplitudes das SRG, 31 nm e 5nm, para filmes de 35 bicamadas de PS119/DAB G1 e PS119/DAB G5, respectivamente. Estas grades foram formadas por transporte de massa causado por efeitos fotônicos, sendo observadas só para luz com polarização p e não sIn this thesis we exploit the control of molecular architecture provided by the Langmuir-Blodgett (LB) and layer-by-layer (LBL) techniques to produce nanostructured films from azobenzene-containing materials, azopolymers and low molecular weight azodyes. The first contribution was associated with the chemical synthesis of azopolymers, in which azochromophores were attached to polymer chains. For LBL film fabrication, which requires water-soluble materials, the sulfonation of the polymer PAZO (poly(p-azophenylene)) led to PAZOS (sulphonated poly(p-azophenylene)) This conjugated azopolymer was luminescent in solution, confirming theoretical predictions, but not in LBL films when alternated with poly(allylamine hydrochloride) (PAH). The latter LBL films displayed electric conductivity when doped with iodine and were also amenable to photoinduced birefringence. The writing of information with a linearly polarized laser was very slow, with writing times considerably longer than for other LBL films due not only to the electrostatic interactions in the film but also to the rigidity of the conjugated chain. The other polymer synthesized and characterized here was DR19CL-IPDI, which is soluble in organic solvents and was used to fabricate Langmuir and LB films. The LB films could only be produced by employing the strategy of co-spreading with an amphiphile, in this case DR19CL-IPDI mixed with cadmium stearate (CdSt). Experiments with photoinduced birefringence in the LB films of DR19CL-IPDI/CdSt indicated higher birefringence than in other polyurethane-based azopolymers because the laser wavelength almost coincides with the wavelength for maximum absorbance. On the other hand, the residual birefringence - after the writing laser was switched off - was smaller than in those similar systems because azochromophore relaxation is facilitated in DR19CL-IPDI due to its lower glass transition temperature. Still with regard to Langmuir films, we have introduced the in situ UV-VIS. spectroscopy technique to analyze films of HPDR13 (poly 4 ’-2-(methacryloyloxy)ethylethylamino -2-chloro-4-nitroazobenzene). Consistent with the pressure-area isotherms, the results from this spectroscopy indicated that at higher subphase temperatures the HPDR13 chains gain flexibility and the molecules can be packed in a more condensed manner, leading to a smaller occupied area per molecule. The importance of molecular architecture control was demonstrated in the study of photoinduced birefringence and formation of surface-relief gratings in LBL films consisting of azodyes alternated with chitosan, and the azopolymer PS119 alternated with DAB (polypropylenimine) dendrimers. In the chitosan LBL films, those containing the azodye Sunset Yellow (SY) exhibited spontaneous birefringence owing to the anisotropy in molecular organization imparted by the LBL technique. For Ponceau S (PS) films, birefringence could be photoinduced with the dynamics of writing depending on the solution pH employed for film fabrication, owing to changes in the intermolecular interactions. The internal structure of LBL films from DAB dendrimers had a large effect on the adsorption of PS119, which increased with the generation, from 1 to 5. The more effective adsorption for G5 dendrimer was due to a larger number of ionized sites for interacting with the azochromophores of PS119. In contrast, the photoinduced birefringence was higher for LBL films of the low generation G1 dendrimer, which was explained by the stronger interpenetration between adjacent layers in the higher generation dendrimers. In LBL films from PS119/DAB G5, this interpenetration restricts the chromophore mobility, leading to a smaller birefringence. Consistent with this explanation, higher amplitudes were obtained for 35-bilayer films of PS119/DAB G1 (31 nm) in comparison with films from PS119/DAB G5 (5 nm). These gratings were formed with mass transport arising from a light-driven mechanism, as photoinscription was only successful with p-polarized light and not with s-polarized light
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Assis, Douglas Ricardo de [UNESP]. "Filmes de Langmuir-Blodgett de nanopartículas de prata." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/136217.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
A auto-organização é uma das ferramentas mais versáteis e mais poderosas para a estruturação de nanopartículas em duas ou três dimensões. A técnica de Langmuir - Blodgett é o método mais promissor para a produção de filmes bidimensionais organizados de tensoativos, polímeros e nanopartículas (NPs), porque proporciona um bom controle da espessura e a homogeneidade da monocamada e de multicamadas. Esse trabalho visa sintetizar nanopartículas de Ag na interface ar-água utilizando filmes de Langmuir-Blodgett de surfactantes como suportes. A síntese das NPs de Ag na interface ar/água foi realizada de acordo com a metodologia de Khomutov e colaboradores. Foi possível sintetizar as NPs de Ag através do espalhamento da mistura das soluções de sulfadiazina de prata e ácido esteárico com razão molar de 1:1. As imagens de microscopia eletrônica de varredura de alta resolução mostram que a ausência de ácido esteárico melhorou a organização das NPs durante a síntese na interface ar/água. A composição química das NPs de prata foi determinada através da espectroscopia de energia dispersiva de raios X acoplada ao microscópio eletrônico operando no modo de varredura. Um estudo comparativo foi feito preparando-se filmes de NPs de Ag. As nanopartículas de Ag recobertas com dodecil sulfato de sódio foram sintetizadas de acordo com o método descrito por Song. As nanopartículas de Ag recobertas com polietilenoglicol (MM ≈ 3400 g.mol-1) e com ácido oléico/oleilamina foram sintetizadas pelo método poliol. Os difratogramas de raios X confirmaram a composição e a fase obtida em cada amostra. Foi estudada a composição do recobrimento das NPs através da espectroscopia na região do infravermelho e quantificado através das análises termogravimétricas. A preparação dos filmes LB de todas as amostras foi feita de acordo com o método descrito por Shin. Através das imagens de microscopia eletrônica de varredura de alta resolução observa-se que somente os filmes LB das nanopartículas de Ag recobertas com ácido oléico e oleilamina apresentam uma organização a longo alcance. Durante a formação dos filmes das amostras recobertas com SDS e com PEG3400 as nanopartículas agregaram prejudicando a organização do sistema. Esse processo de agregação pode ser atribuído a falta de surfactante na superfície das NPs ou ao excesso de polímero que aprisiona as nanopartículas no meio de suas cadeias carbônicas interferindo na organização de NPs.
Self-assembly is one of the most powerful and versatile tools for structuring nanoparticles in two or three dimensions. The Langmuir–Blodgett (LB) technique is the most promising method for production of organized surfactants, polymers, and nanoparticles (NPs) two-dimensional films, because it provides good control of the thickness and homogeneity of the mono and multilayer. This paper aims to synthesize silver nanoparticles in the air-water interface using surfactants Langmuir-Blodgett films such as “templates”. The synthesis of Ag NPs in the air / water interface was performed according the Khomutov methodology [1] it was possible to synthesize Ag NPs by spreading the mixture of silver sulfadiazine solutions and stearic acid molar ratio 1: 1. Field emission gun scanning electron microscope (FEG-SEM) images show that the absence of stearic acid improved the arrangement of NPs during synthesis in the air / water interface. The chemical composition of silver NPs was determined by energy dispersive X-ray spectroscopy attached to the electron microscope operating in scan mode. A comparative study was made preparing Ag NPs films. The Ag nanoparticles coated with sodium dodecyl sulfate were synthesized according to the method described by Song. The Ag nanoparticles coated with polyethylene glycol (MW ≈ 3400 g / mol) and oleic acid / oleylamine was synthesized by the polyol method. The X-ray diffraction confirmed the composition and phase obtained in each sample. It studied the composition of the coating of NPs through spectroscopy in the infrared region and quantified through thermogravimetric analysis. The preparation of LB films of a silver nanoparticles covered with oleic acid and olelamine (Ag@AO/OL) was done according to the methodology described by Shin et al. The images obtained by electron microscopy high resolution scan can be observed that only the LB films of Ag nanoparticles coated with oleic acid and oleylamine have an organization-reaching. During the formation of the films of the other samples the aggregated nanoparticles damaging the system organization. This aggregation process may be attributed to the lack of surfactant on the surface of the NPs or excess polymer which entraps the nanoparticles in the middle of their carbon chains interfering with NPs organization.
CNPq: 139251/2013-8
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Antoine, Claire. "Composés d'insertion inorganiques en films de Langmuir-Blodgett." Paris 11, 1989. http://www.theses.fr/1989PA112328.
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L'étude des composés organiques ou minéraux en films minces a montré qu'ils présentaient des propriétés tout à fait originales par rapport aux composés massifs. Le présent travail vise à l'obtention de semi-conducteurs minéraux en films ultraminces, en particulier des sulfures métalliques de mercure et de cadmium. La synthèse est réalisée dans des conditions douces au sein d'une matrice organique réalisée grâce à la technique de Langmuir-Blodgett, par diffusions successives des réactifs minéraux. La formation des sels, contrôlée géométriquement par la matrice d'accueil, est suivie par spectroscopie IR. Les propriétés physiques de ces composés ont été étudiées par différentes techniques : spectroscopies U. V. Visible et I. R. , dichroïsme linéaire, diffraction des RX, X. P. S. , conduction, etc. . . Les propriétés structurales et électroniques de ces films ultraminces ces confirment que les sulfures métalliques adoptent une géométrie lamellaire d'épaisseur moléculaire. La conductivité et la photoconductivité sont interprétées par un diagramme de bande classique et confirment l'existence d'un plan continu. Cette méthode de synthèse ouvre la voie vers une nouvelle famille de matériaux ultrafins aux propriétés électroniques originales. Ce travail a fait l'objet de deux publications, et d'un dépôt de brevet.
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CORONEL, PHILIPPE. "Etude de materiaux magnetiques en film langmuir-blodgett." Paris 11, 1990. http://www.theses.fr/1990PA112203.
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Un des points cles de l'electronique moleculaire est la realisation de systemes organises ayant des proprietes specifiques portes par les molecules, l'une d'entre elles devrait permettre le stockage d'information. Dans ce but nous avons mene une etude exploratoire en elaborant un complexe magnetique dans une organisation bidimensionnelle, ceci dans l'optique d'obtenir une memoire magnetique moleculaire. Pour y parvenir nous avons choisi comme propriete; la bistabilite moleculaire propre aux materiaux magnetiques qui presentent le phenomene de transition de spin. Deux familles de complexes types ont ete etudiees: (phenantroline)2fe(ncs)2 et fe(8quinolylsalicylaldimine)2(x-). La fabrication d'un systeme organise bidimensionnel est possible grace a la technique de langmuir-blodgett, celle-ci nous a permis trois voies de synthese: voie a (synthese in situ), voie b (semi-amphiphile), voie c (amphiphile). Dans le cadre de ce memoire nous avons voulu savoir si l'existence du phenomene de transition de spin en 3d(poudre) etait transposable en 2d(film lb). Les resultats nous ont permis de juger l'importance de l'ajout de chaines aliphatiques sur le caractere du ligand ainsi que sur la geometrie du complexe quant a la propriete magnetique du complexe et son comportement en temperature (etude du fer (iii) et des transformations) sur le phenomene de transition de spin engendrees par le passage du systeme tridimensionnel a celui bidimensionnel (etude du fer(ii) et evaluation du couplage dans le plan polaire du film lb). Cette etude a presente un resultat tres positif qui est la transition de spin cooperative en film lb; c'est un premier pas vers la realisation d'une memoire magnetique moleculaire
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Ouattara, Mariane. "Polymères amphiphiles : des films Langmuir-Blodgett au transistor." Doctoral thesis, Université Laval, 2016. http://hdl.handle.net/20.500.11794/26569.
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Au cours des 25 dernières années, l’intérêt pour l’utilisation de semi-conducteurs organiques comme couche active dans les transistors à effet de champ (TOECs), à la place du silicium, a crû spectaculairement. L’utilisation de polymères π-conjugués dans ce domaine a grandement entraîné cet essor. Au fil du temps, on observe une amélioration des performances atteintes contribuant à l’émergence de nouveaux matériaux. Par contre, différents paramètres tels que la mobilité et la stabilité demeurent moins impressionnants que ceux des semi-conducteurs à base de matériaux inorganiques. De meilleurs résultats pourraient être obtenus si le transport de charges se faisait sans entraves. Ainsi, une très bonne organisation au sein des matériaux utilisés est nécessaire. Dans cette optique, des polymères conjugués amphiphiles constitués d’unités thiéno [3,4-c] pyrrole-4,6-dione (TPD) ont été synthétisés. En se servant de la technique Langmuir-Blodgett (LB) pour optimiser l’organisation des molécules au sein des films, il a été possible de réaliser des films stables avec des pressions de collapse de 60 mN/m. Les microscopies à angle de Brewster (BAM) et à force atomique (AFM) nous ont démontré l’homogénéité des films à l’interface air-eau (BAM) et une fois transférés sur un substrat solide (AFM). L’orientation a été étudiée principalement par spectroscopie infrarouge à réflexion totale atténuée (ATR). D’autres techniques spectroscopiques comme l’UV-visible, la spectroscopie infrarouge de réflexion absorption par modulation de polarisation (PM-IRRAS) et l’ellipsométrie ont permis de corroborer les résultats obtenus via l’ATR. Les mesures ont permis de confirmer l’obtention de l’orientation préférentielle hors du plan. Pour compléter ce projet, des tests ont été effectués avec des transistors organiques. Des valeurs de mobilité intéressantes de 1,2 × 10-3 cm2/(V.s) ont été enregistrées pour des transistors obtenus à partir de films LB.Over the past 25 years, interest in the use of organic semiconductors as active layers in field effect transistors (TFTs) instead of silicon has grown dramatically. The use of π-conjugated polymers in this area has greatly driven this growth. Over time, there has been an improvement in performance achieved contributing to the emergence of new materials. However, the performances of organic semiconductors remains inferior that of their inorganic counterpart regarding parameters such as the mobility and stability. Better results could be achieved if the charge transport was done without hindrance. Thus, a very good organiza- tion within the material is needed. In this regard, amphiphilic polymers based on thieno [3,4-c] pyrrole-4,6-dione (TPD) units were synthesized. By using the Langmuir-Blodgett technique (LB) to optimize the organization of the molecules within the films, it was possible to achieve stable films with a collapse pressure of 60 mN/m. Brewster angle (BAM) and atomic force (AFM) microscopies have demonstrated that homogeneous films are obtained at the air-water interface (BAM) and remain so once transferred onto a solid substrate (AFM). Orientation has been studied mainly by attenuated total reflection infrared spectroscopy (ATR). Other spectroscopic techniques such as UV-visible, absorption polarization modulation infrared reflection spectroscopy (PM-IRRAS) and ellipsometry have confirmed the ATR results. Measurements show that molecules adopted an edge-on orientation in the polymer films. To complete this project, organic transistors were fabricated. Interesting mobility values of 1.2 × 10-3 cm2/(V.s) were recorded for organic LB film transistors.
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Paterlini, Thaís Tognoli. "Estudo das interações de proteínas osteogênicas com lipídios em filmes de Langmuir e Langmuir-Blodgett." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/59/59138/tde-10042018-193103/.
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O estudo das propriedades das membranas celulares, assim como sua interação com íons e moléculas é de fundamental importância para o entendimento de processos biológicos complexos, como a formação do tecido ósseo. O osso natural é constituído por compostos orgânicos, especialmente proteínas como o colágeno, e por minerais, como a hidroxiapatita. O processo pelo qual ocorre a formação do componente inorgânico é chamado de biomineralização, um processo complexo mediado pela liberação de vesículas da matriz (VM), secretadas em locais específicos a partir de osteoblastos. Essas VM são ricas nas principais biomoléculas envolvidas nesse processo, como as proteínas anexina, em especial a anexina V (AnxA5), que exercem papel importante como, formação de canais de cálcio e ligação com o colágeno, criando assim um microambiente adequado para a formação inicial e propagação dos cristais de hidroxiapatita a partir de fibrilas de colágeno. No presente estudo foi possível incorporar colágeno e AnxA5 em sistemas modelo para estudos de biomineralização, utilizando-se monocamadas de Langmuir e os filmes Langmuir-Blodgett (LB). As monocamadas foram formadas com os principais grupos carregados de lipídios encontrados nas VM: fosfatidilcolina (PC) e fosfatidilserina (PS). As monocamadas formadas por lipídios, colágeno e AnxA5 foram depositadas sobre discos de titânio utilizando-se a técnica dos filmes LB. Os filmes formados foram expostos a uma solução que simula o pH e força iônica do fluido corpóreo, de maneira a mimetizar a precipitação de hidroxiapatita. As amostras foram caracterizadas por microscopia eletrônica de varredura (MEV), espectroscopia vibracional na região do infravermelho (FTIR) e difração de raios X (EDX). Além disso, estudou-se as propriedades de molhabilidade e energia livre de superfície das amostras de titânio modificadas. Colágeno e AnxA5 interagiram com os lipídios, como mostrado nas isotermas. Interação preferencial foi observada no sistema binário contendo DPPC e DPPS e na presença de íons cálcio, como ocorre nos sistemas naturais. A presença das proteínas e dos fosfolipídios nos filmes LB sobre as superfícies de titânio foram essenciais para formação de nanopartículas de hidroxiapatita biomimética.The study of the properties of cell membranes, as well as their interaction with ions and molecules, is of fundamental importance for the understanding of complex biological processes, such as the formation of bone tissue. The natural bone consists of organic compounds, especially proteins like collagen, and minerals, such as hydroxyapatite. The process which the formation of the inorganic component takes place is called biomineralization, a complex process mediated by the release of matrix vesicles (MV), secreted at specific sites from osteoblasts. These MVs are rich in the main biomolecules involved in this process, such as annexin proteins, especially annexin V (AnxA5), which play an important role as calcium channels formation and binding with collagen, thus creating a suitable microenvironment for formation initial and propagation of the hydroxyapatite crystals from collagen fibrils. In the present study, it was possible to incorporate collagen and AnxA5 into model systems for biomineralization studies using Langmuir monolayers and Langmuir-Blodgett (LB) films. The monolayers were formed with the main lipid groups found in MVs: phosphatidylcholine (PC) and phosphatidylserine (PS). The monolayers formed by lipids, collagen and AnxA5 were deposited on titanium plates using the LB film technique. The films were exposed to a solution that simulates the pH and ionic strength of the body fluid in order to mimic the precipitation of hydroxyapatite. The samples were characterized by scanning electron microscopy (SEM), infrared vibration spectroscopy (FTIR) and X-ray diffraction (XRD). In addition, the wettability and surface free energy properties of the modified titanium samples were studied. Collagen and AnxA5 interacted with lipids, as shown in the isotherms. Preferential interaction was observed in the binary system containing DPPC and DPPS and in the presence of calcium ions, as occurs in natural systems. The presence of the proteins and the phospholipids in the LB films on the titanium surfaces were essential for the formation of biomimetic hydroxyapatite nanoparticles.