Submitted by Angela Maria de Oliveira (amolivei@uepg.br) on 2018-02-07T12:42:14Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Rolf de Campos.pdf: 5588727 bytes, checksum: d81ab37d8cd335285d51711794fbbc44 (MD5) / Made available in DSpace on 2018-02-07T12:42:14Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Rolf de Campos.pdf: 5588727 bytes, checksum: d81ab37d8cd335285d51711794fbbc44 (MD5) Previous issue date: 2017-07-05 / Fundação Araucária de Apoio ao Desenvolvimento Científico e Tecnológico do Paraná / Esta tese descreve as interações entre o surfactante não iônico p-(1,1,3,3 tetrametilbutil) fenil polietilenoglicol (denominado Triton X) e dodecil sulfato de sódio (SDS) com o polímero catiônico 3-cloreto-n-propilpiridínio silsesquioxano (SiPy) na presença da ftalocianina tetrasulfonada de níquel (NiTsPc), as quais foram avaliadas utilizando medidas de tensão superficial e viscosidade. Os efeitos dessas interações também foram estudados quando estes polieletrólitos foram transferidos para filmes finos pela técnica LbL sobre substrato condutor (óxido de estanho dopado com índio – ITO), quartzo e silício. Observou-se, por meio de técnica espectroscópica de absorção na região do UVVis, que há um efeito sinérgico proporcionado pela interação dos polieletrólitos catiônico (SiPy/surfactante) e aniônico (NiTsPc) nos filmes LbL. Por técnicas espectroscópicas FTIR e Raman, e técnicas eletroquímicas tais como impedância eletroquímica e voltametria cíclica, foi constatado que há coexistência de micelas mistas e puras e que a adsorção destes agregados tem um papel importante na superfície dos filmes LbL. Foi também realizada a síntese e a caracterização de nanopartículas de hidróxido de níquel, em sua fase α, estabilizadas pelo polímero SiPy, e pelo surfactante zwiteriônico 3-(1- alquil-3-imidazólio)propano-sulfonado. O surfactante ImS3-14 foi escolhido por sua interação preferencial com ânions, tornando-o um excelente limitante para o crescimento das nanopartículas de Ni(OH)2. A formação dos agregados foi caracterizada por espalhamento dinâmico de luz e potencial zeta, para determinar tamanho e carga das nanopartículas, respectivamente. Após a síntese das nanopartículas, estas foram depositadas através da técnica LbL em vários substratos. O crescimento dos filmes foi acompanhado por UV-VIS e sua caracterização foi realizada pelas técnicas de FTIR, Raman, AFM e MEV-FEG. As características eletroquímicas dos filmes foram estudadas por voltametria cíclica (VC) e espectroscopia de impedância eletroquímica (EIE). / This thesis describes the interactions between the nonionic surfactant p-(1,1,3,3- tetramethylbutyl)phenyl-polyethylene glycol (Triton X) and sodium dodecyl sulfate (SDS) with the cationic polymer 3-chloride-n-propylpyridinium silsesquioxane (SiPy) in the presence of nickel phthalocyanine tetrasulfonate (NiTsPc), which they were evaluated using surface tension and viscosity measurements. The effects of these interactions were also studied when these polyelectrolytes were transferred to thin films by the LbL technique on conductive substrate (indium doped tin oxide - ITO), quartz and silicon. It has been observed by UV-Vis absorption spectroscopy there is a synergistic effect provided by the interaction of the cationic polyelectrolytes (SiPy / surfactant) and anionic (NiTsPc) polyelectrolytes in the LbL films. Spectroscopic techniques, such as, FTIR and Raman, and electrochemical techniques, electrochemical impedance and cyclic voltammetry, it was observed that there is a coexistence of mixed and pure micelles. The adsorption of these aggregates plays an important role on the surface of the LbL films. The synthesis and characterization of nickel hydroxide nanoparticles, in their α phase, stabilized by the SiPy polymer, and by the zwitterionic surfactant 3- (1-alkyl-3 - imidazolium) propane sulfonate was realized. The surfactant ImS3-14 was chosen for its preferential interaction with anions, making it an excellent stabilizer for the growth of the Ni(OH)2 nanoparticles. The formation of the aggregates was characterized by dynamic scattering of light (DLS) and zeta potential to determine size and charge, respectively. After the synthesis of the nanoparticles, they were deposited by the LbL technique on several substrates. The growth of the films was accompanied by UV-VIS and their characterization was evaluated by FTIR, Raman, AFM and MEV-FEG techniques. The electrochemical characteristics of the films were studied using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS).

Control and analysis of protein aggregation is an increasing challenge to biopharmaceutical research and development. Therefore it is important to understand the interactions, causes and analysis of particles in order to control protein aggregation to enable successful biopharmaceutical formulations. This work investigates the role of different non-ionic surfactants on protein conformational stability, as assessed by HSDSC, and on protein size stability as assessed by Dynamic Light Scattering (DLS), HIAC and MFI. BSA and IgG2 were used as model proteins. Thermal unfolding experiments indicated a very weak surfactant-immunoglobulin IgG2 interaction, compared to much stronger interactions for the BSA surfactant systems. The DLS results showed that BSA and IgG2 with different surfactants and concentration produced different levels of particle size growth. The heat treatment and aging of samples in the presence of Tween 20, Tween 80, Brij 35 and Pluronic F-68 surfactants led to an increase in the populations of larger particles for BSA samples, whereas IgG2 systems did not notably aggregate under storage conditions MFI was shown to be more sensitive than HIAC technique for measuring sub-visible particles in protein surfactant systems. Heat treatment and storage stress showed a significant effect on BSA and IgG2 protein sub-visible particle size stability. This work has demonstrated that both proteins with different Tween 20, Tween 80, Brij 35 and Pluronic F-68 concentrations, have different level of conformational and size stability. Also aging samples and heating stress bears the potential to generate particles, but this depends on surfactant type. Poor predictive correlations between the analytical methods were determined.

Neste trabalho, realizamos um estudo das propriedades estruturais e elásticas da fase lamelar e também das interações relevantes que levam à estabilização dessa estrutura periódica. A composição da membrana, assim como sua hidratação, foi variada de maneira sistemática com o objetivo de introduzir alterações na flexibilidade da bicamada e no regime de confinamento. A fase lamelar é constituída de lecitina à qual é incorporado, em diferentes proporções, um co-surfactante comercial, formado por uma mistura de ácidos graxos etoxilados, Para o estudo das interações entre as bicamadas a fase lamelar foi submetida a uma pressão osmótica conhecida. Por meio de experimentos de SAXS, foram determinados os parâmetros estruturais que caracterizam a fase lamelar, para um dado valor de pressão. Os resultados experimentais obtidos são ajustados considerando-se um potencial efetivo de interação entre as bicamadas, permitindo a determinação de parâmetros quantitativos, caracterizando as diferentes contribuições atrativa e repulsivas. Em um segundo momento, foi realizado um estudo para caracterização da fase lamelar, desta vez, introduzindo um co-surfactante não comercial com o objetivo de investigar as alterações que ocorrem na interface devido à presença dos grupos etoxilados. Observa-se que a incorporação do co-surfactante amplia o domínio de diluição da fase lamelar atingindo período em torno de 200 Å, sem domínios de coexistência de duas fases lamelares, como se observa com o co-surfactante comercial polidisperso. O uso de um produto mais bem caracterizado, permite observações mais claras sobre mudanças no comportamento do parâmetro de Caillé, que caracteriza a flexibilidade da membrana, assim como alterações que ocorrem na interface, seja por efeito de confinamento ou por efeito de temperatura. / In this work, we carried out a study of structural and elastic properties of the lamellar phase and the relevant interactions that lead to stabilization of this periodic structure. The composition of the membrane, as well as hydration, was varied systematically in order to introduce changes in the flexibility of the bilayer and confinement regime. The lamellar phase is composed by lecithin, in which is incorporated in different proportions a commercial co-surfactant consisting of a mixture of ethoxylated fatty acids, To study the interactions between the bilayers the lamellar phase was placed under a known osmotic pressure. Structural parameters characterizing the lamellar phase were determined by SAXS experiments, for a given value of pressure. The experimental results are fitted considering an effective potential of interaction between the bilayers, allowing the determination of quantitative parameters characterizing the different attractive and repulsive contributions. In a second step, studies for characterization of the lamellar phase were carried out, but at this time, introducing a non-commercial co-surfactant with the aim of investigating the changes that occur at the interface due to the presence of ethoxylated groups. It is observed that the incorporation of co-surfactant extends the dilution limit of the lamellar phase, reaching lamellar periodicities around 200 Å, without coexistence of two lamellar phases, as observed with the commercial polydisperse co-surfactant. Using a more well characterized product, it is clearer the changes on the behavior of Caillé parameter, which characterizes the flexibility of the membrane, as well as changes occurring at the interface, either by confinement or temperature effects.

Neste trabalho, realizamos um estudo das propriedades estruturais e elásticas da fase lamelar e também das interações relevantes que levam à estabilização dessa estrutura periódica. A composição da membrana, assim como sua hidratação, foi variada de maneira sistemática com o objetivo de introduzir alterações na flexibilidade da bicamada e no regime de confinamento. A fase lamelar é constituída de lecitina à qual é incorporado, em diferentes proporções, um co-surfactante comercial, formado por uma mistura de ácidos graxos etoxilados, Para o estudo das interações entre as bicamadas a fase lamelar foi submetida a uma pressão osmótica conhecida. Por meio de experimentos de SAXS, foram determinados os parâmetros estruturais que caracterizam a fase lamelar, para um dado valor de pressão. Os resultados experimentais obtidos são ajustados considerando-se um potencial efetivo de interação entre as bicamadas, permitindo a determinação de parâmetros quantitativos, caracterizando as diferentes contribuições atrativa e repulsivas. Em um segundo momento, foi realizado um estudo para caracterização da fase lamelar, desta vez, introduzindo um co-surfactante não comercial com o objetivo de investigar as alterações que ocorrem na interface devido à presença dos grupos etoxilados. Observa-se que a incorporação do co-surfactante amplia o domínio de diluição da fase lamelar atingindo período em torno de 200 Å, sem domínios de coexistência de duas fases lamelares, como se observa com o co-surfactante comercial polidisperso. O uso de um produto mais bem caracterizado, permite observações mais claras sobre mudanças no comportamento do parâmetro de Caillé, que caracteriza a flexibilidade da membrana, assim como alterações que ocorrem na interface, seja por efeito de confinamento ou por efeito de temperatura. / In this work, we carried out a study of structural and elastic properties of the lamellar phase and the relevant interactions that lead to stabilization of this periodic structure. The composition of the membrane, as well as hydration, was varied systematically in order to introduce changes in the flexibility of the bilayer and confinement regime. The lamellar phase is composed by lecithin, in which is incorporated in different proportions a commercial co-surfactant consisting of a mixture of ethoxylated fatty acids, To study the interactions between the bilayers the lamellar phase was placed under a known osmotic pressure. Structural parameters characterizing the lamellar phase were determined by SAXS experiments, for a given value of pressure. The experimental results are fitted considering an effective potential of interaction between the bilayers, allowing the determination of quantitative parameters characterizing the different attractive and repulsive contributions. In a second step, studies for characterization of the lamellar phase were carried out, but at this time, introducing a non-commercial co-surfactant with the aim of investigating the changes that occur at the interface due to the presence of ethoxylated groups. It is observed that the incorporation of co-surfactant extends the dilution limit of the lamellar phase, reaching lamellar periodicities around 200 Å, without coexistence of two lamellar phases, as observed with the commercial polydisperse co-surfactant. Using a more well characterized product, it is clearer the changes on the behavior of Caillé parameter, which characterizes the flexibility of the membrane, as well as changes occurring at the interface, either by confinement or temperature effects.

Microbially induced calcite precipitation (MICP) has been used for a number of years as a technique for the improvement of various geological materials. MICP has been used in a limited capacity in organic rich soils with varying degrees of success. Investigators hypothesized that microbially-induced cementation could be improved in organic soils by using a surfactant. Varying amounts of Sodium Dodecyl Sulfate (SDS) were added to soils of varying organic content and a mixing procedure was used to treat these soils via MICP. Treated specimens were tested for unconfined compressive strength (UCS). Results appeared to show direct relationships between SDS content and treated specimen strength although significant variability was present in the data. In addition, results also indicated that while addition of SDS during MICP treatment strengthens soil, the strengthening is likely from the formation of a calcium dodecyl sulfate (CDS) complex in which the CDS surrounds the soil in a matrix, and formation of MICP-induced calcite has very little to do with overall soil performance. As such, a new method for stabilizing loose soils dubbed ‘Surfactant-induced soil stabilization’ (SISS) was further explored by treating additional soil specimens. Samples treated using this technique showed increases in strength when compared to untreated specimens. In addition, preliminary data indicated that SISS treated specimens were insoluble. The SISS technique presents a number of advantages when compared to traditional soil stabilization techniques. In particular it should be relatively low-cost and simple to administer since its only components are SDS and calcium chloride. Additionally, these constituents are relatively more sustainable than chemicals associated with more-traditional loose soil stabilization techniques.

<p>Cellulose ethers and polyethylene glycols are used in drug formulations as water swelling or water soluble matrices. Polar lipids, for example monoglycerides, and surfactants can be used to solubilise hydrophobic or amphiphilic drugs and to formulate potential drug delivery vehicles such as emulsions, liposomes and cubic phases. In this thesis mixtures of these excipients are characterised in various environments, from dilute aqueous solutions to solid dispersions. Special focus has been on the understanding of the associating processes involved.</p><p>Detailed understanding of the association of cellulose ethers, of varying hydrophobicity, and amphiphilic substances is presented. The hydrophobicity of the polymer was found to have an impact on the interaction scheme. The amphiphiles were found to bind at lower amphiphile concentrations to a more hydrophobic polymer thus influencing both micro- and macroscopic structure of the aggregates. </p><p>The choice of counterion to the amphiphile has a small but significant effect on the interaction and the structure of the aggregates. Also amphiphilic drug molecules can interact with nonionic polymers in a similar way as surfactants in aqueous solution. Due to the higher cmc of the drug ibuprofen the interaction is largely influenced by the ionic strength of the solution. The type of amphiphile also influences the cooperativity of the amphiphile-polymer binding.</p><p>In more concentrated systems liquid crystals are formed into which the polymer interact with the amphiphiles. Both cubic and sponge phases were found with relatively large polymers interacting with polar lipids. These phases were found to swell and shrink mainly controlled by the amount of polymer inside them. Also membrane interacting substances added to the sponge phase could influence the size of the water channels in the phase. </p><p>In water free systems polymers and polar lipids were found to interact as well as forming solid dispersions. The behaviour of the phase separation between polymer and lipid depended on the concentration of the dispersed phase. The polar lipid was found to be distributed in the lamellar part of the semicrystalline polymer influencing the polymer folding.</p>

Communication and reconnaissance systems are requiring increasing flexibility concerning functionality and efficiency for multiband and broadband frequency applications. Circuit-based reconfiguration mechanisms continue to promote radio frequency (RF) application flexibility; however, increasing limitations have resulted in hindering performance. Therefore, the implementation of a "wireless" reconfiguration mechanism provides the required agility and amicability for microwave circuits and antennas without local overhead. The wireless reconfiguration mechanism in this thesis integrates dynamic, fluidic-based material systems to achieve electromagnetic agility and reduce the need for "wired" reconfiguration technologies. The dynamic material system component has become known as electromagnetically functionalized colloidal dispersions (EFCDs). In a microfluidic reconfiguration system, they provide electromagnetic agility by altering the colloidal volume fraction of EFCDs - their name highlights the special considerations we give to material systems in applied electromagnetics towards lowering loss and reducing system complexity. Utilizing EFCDs at the RF device-level produced the first circuit-type integration of this reconfiguration system; this is identified as the coaxial stub microfluidic impedance transformer (COSMIX). The COSMIX is a small hollowed segment of transmission line with results showing a full reactive loop (capacitive to inductive tuning) around the Smith chart over a 1.2 GHz bandwidth. A second microfluidic application demonstrates a novel antenna reconfiguration mechanism for a 3 GHz microstrip patch antenna. Results showed a 300 MHz downward frequency shift by dielectric colloidal dispersions. Magnetic material produced a 40 MHz frequency shift. The final application demonstrates the dynamically altering microfluidic system for a 3 GHz 1x2 array of linearly polarized microstrip patch antennas. The parallel microfluidic capillaries were imbedded in polydimethylsiloxane (PDMS). Both E- and H-plane designs showed a 250 MHz frequency shift by dielectric colloidal dispersions. Results showed a strong correlation between decreasing electrical length of the elements and an increase of the volume fraction, causing frequency to decrease and mutual coupling to increase. Measured, modeled, and analytical results for impedance, voltage standing wave ratio (VSWR), and radiation behavior (where applicable) are provided.

Aufgrund des großen Verhältnisses von Oberfläche zu Volumen zeigen Nanopartikel interessante, größenabhängige Eigenschaften, die man im ausgedehnten Festkörper nicht beobachtet. Sie sind daher von großem wissenschaftlichem und technologischem Interesse. Die Herstellung kleinster Partikel ist aus diesem Grund überaus wünschenswert. Dieses Ziel kann mit Hilfe von Mikroemulsionen als Templatphasen bei der Herstellung von Nanopartikeln erreicht werden. Mikroemulsionen sind thermodynamisch stabile, transparente und isotrope Mischungen von Wasser und Öl, die durch einen Emulgator stabilisiert sind. Sie können eine Vielzahl verschiedener Mikrostrukturen bilden. Die Kenntnis der einer Mikroemulsion zugrunde liegenden Struktur und Dynamik ist daher von außerordentlicher Bedeutung, um ein gewähltes System potentiell als Templatphase zur Nanopartikelherstellung einsetzen zu können.<br><br> In der vorliegenden Arbeit wurden komplexe Mehrkomponentensysteme auf der Basis einer natürlich vorkommenden Sojabohnenlecithin-Mischung, eines gereinigten Lecithins und eines Sulfobetains als Emulgatoren mit Hilfe der diffusionsgewichteten 1H-NMR-Spektroskopie unter Verwendung gepulster Feldgradienten (PFG) in Abhängigkeit des Zusatzes des Polykations Poly-(diallyl-dimethyl-ammoniumchlorid) (PDADMAC) untersucht. Der zentrale Gegenstand dieser Untersuchungen war die strukturelle und dynamische Charakterisierung der verwendeten Mikroemulsionen hinsichtlich ihrer potentiellen Anwendbarkeit als Templatphasen für die Herstellung möglichst kleiner Nanopartikel.<br><br> Die konzentrations- und zeit-abhängige NMR-Diffusionsmessung stellte sich dabei als hervorragend geeignete und genaue Methode zur Untersuchung der Mikrostruktur und Dynamik in den vorliegenden Systemen heraus. Die beobachtete geschlossene Wasser-in-Öl- (W/O-) Mikrostruktur der Mikroemulsionen zeigt deutlich deren potentielle Anwendbarkeit in der Nanopartikelsynthese. Das Gesamtdiffusionsverhalten des Tensides wird durch variierende Anteile aus der Verschiebung gesamter Aggregate, der Monomerdiffusion im Medium bzw. der medium-vermittelten Oberflächendiffusion bestimmt. Dies resultierte in einigen Fällen in einer anormalen Diffusionscharakteristik. In allen Systemen liegen hydrodynamische und direkte Wechselwirkungen zwischen den Tensidaggregaten vor.<br><br> Der Zusatz von PDADMAC zu den Mikroemulsionen resultiert in einer Stabilisierung der flüssigen Grenzfläche der Tensidaggregate aufgrund der Adsorption des Polykations auf den entgegengesetzt geladenen Tensidfilm und kann potentiell zu Nanopartikeln mit kleineren Dimensionen und schmaleren Größenverteilungen führen. / Owing to their large surface-to-volume ratio nanoparticles show interesting size-dependent properties that are not observable in bulk materials. Thus, they are of great scientific and technological interest. Thereby, the highly desirable preparation of as small particles as possible might be easily achieved using microemulsions as template phases. Microemulsions are thermodynamically stable, transparent and isotropic mixtures of water and oil stabilized by an emulsifying agent. However, microemulsions may form a great variety of different microstructures. Thus, it is of utmost importance to know the underlying microstructure and microdynamics of a chosen microemulsion system in order to use it as a template phase for nanoparticle formation.<br><br> In the present study complex multi-component microemulsion systems based on a naturally occurring soybean lecithin mixture, purified lecithin and sulfobetaine as emulsifiers were investigated by diffusion-weighted pulsed field gradient (PFG) 1H NMR spectroscopy in the presence and absence of the polycation poly-(diallyldimethylammonium chloride) (PDADMAC). The central topic of this study was to structurally and dynamically characterize the present microemulsions with respect to their potential use in nanoparticle formation.<br><br> The concentration- and time-dependent NMR diffusion measurements turned out to be a suitable and accurate tool to investigate the microstructure and microdynamics of the systems under investigation. They reveal closed water-in-oil (W/O) microemulsion microstructures which prove the potential suitability of the respective systems as template phases for the preparation of nano-sized particles. The overall diffusion behavior of surfactants were found to be governed by varying contributions from displacements of entire aggregates, monomer diffusion in the medium and bulk-mediated surface diffusion, respectively. In some cases this led to a marked anomalous diffusion characteristics. In all systems interactions between aggregates are dominated by hydrodynamic and direct forces.<br><br> The addition of PDADMAC to the microemulsion systems results in a stabilization of the liquid interface of surfactant aggregates due to the adsorption of the polycation at the oppositely charged surfactant film and may potentially lead to nanoparticles of smaller dimensions and narrower size distributions.

This thesis has the dual purpose of raising awareness of the importance of the mixing protocol on the end products of polyelectrolyte-oppositely charged surfactant systems, and to contribute to a better understanding of the properties of bottle-brush polyelectrolytes when adsorbed onto interfaces. In the first part of this thesis work, the effects of the mixing protocol and the mixing procedure on formed polyelectrolyte-oppositely charged surfactant aggregates were investigated. It was shown that the initial properties of the aggregates were highly dependent on the mixing parameters, and that the difference between the resulting aggregates persisted for long periods of time. The second part of the studies was devoted to the surface properties of a series of bottle-brush polyelectrolytes made of charged segments and segments bearing poly(ethylene oxide) side chains; particular attention was paid to the effect of side chain to charge density ratio of the polyelectrolytes. It was shown that the adsorbed mass of the polyelectrolytes, and the corresponding number of poly(ethylene oxide) bearing segments at the interface, went through a maximum as the charge density of the polyelectrolyte was increased. Also, it was found that bottle-brush polyelectrolyte layers were desorbed quite easily when subjected to salt solutions. This observation was rationalized by the unfavourable excluded volume interactions between the side chains and the entropic penalty of confining them at an interface, which weaken the strength of the binding of the polyelectrolytes to the interface. However, it was shown that the same side chains effectively protect the adsorbed layer against desorption when the layer is exposed to solutions containing an oppositely charged surfactant. Investigation of the lubrication properties of the bottle-brush polyelectrolytes in an asymmetric (mica-silica) system also related the observed favourable frictional properties to the protective nature of the side chains. The decisive factor for achieving very low coefficients of friction was found to be the concentration of the side chains in the gap between the surfaces. Interestingly, it was shown that a brush-like conformation of the bottle-brush polyelectrolyte at the interface has little effect on achieving favourable lubrication properties. However, a brush-like conformation is vital for the resilience of the adsorbed layer against the competitive adsorption of species with a higher surface affinity. / QC 20100830

In this thesis the structure and hydration of small organic and amphipilic compounds adsorbed at the air-liquid interface, have been studied using the nonlinear optical technique Vibrational Sum Frequency Spectroscopy (VSFS). The second order nature of the sum frequency process makes this technique particularly surface sensitive and very suitable for interfacial studies, as molecules at the surface can be distinguished even in the presence of a vast excess of the same molecules in the bulk. Particular emphasis was given to the surface water structure and how it is affected by the presence of small model compounds such as acetic acid and formic acid, and also non-ionic surfactants with sugar based and ethylene oxide based polar headgroups. Understanding the structure of water at these interfaces is of considerable fundamental importance, and here VSFS provided unique information. Upon addition of tiny amounts of these surface active compounds, the ordered surface structure of water was found to be significantly perturbed, as revealed by the changes observed in the characteristic spectroscopic signature of the dangling OH bond of water molecules, which vibrate free in air and are present in the top monolayer. Dramatic differences between the different compounds were also observed in the bonded OH region, providing a valuable insight into the hydration of polar groups at interfaces. Additionally, by employing different polarization combinations of the laser beams involved in the sum frequency process, information about the different water species present at the surface and their average orientation were extracted. In particular an unusual state of water was found with a preferred orientation in a non-donor configuration in close proximity to the hydrophobic region formed by the hydrocarbon tails of the surfactant molecules. The conformation and orientation of the different adsorbates were also characterized, targeting their specific vibrational frequencies. Noteworthy is the orientation of the fluorocarbon chain of ammonium perfluorononanoate (APFN), which in contrast to the hydrocarbon chains of the other surfactant molecules studied, remained constant over a wide range of surface densities. This behaviour was also observed for the anionic headgroup of sodium dodecyl sulphate (SDS). Other interesting findings were the formation of a cyclic dimer bilayer at the surface of concentrated aqueous solutions of acetic acid and the water structuring effect induced by poly(ethylene-oxide) headgroups, in spite of being themselves disordered at the air-liquid interface.