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A facile synthesis was employed for three polyhedral oligo silsequioxanes (POSS), obtaining incompletely condensed structures with fern-like and cubic morphologies. Proton nuclear magnetic resonance spectroscopy (1H NMR) indicated the successful synthesis of the proposed POSS structures. The hydroxyl groups affected the manner and type of POSS morphology, as seen under a scanning electron microscope (SEM) and a transmission electron microscope (TEM). Fourier-transform infrared spectroscopy (FTIR) showed the availability of surface hydroxyl groups that contributed to the formation of a higher amount of char residue, as found from TGA analysis. The highest decomposition temperature (281 °C) and the least char residue were found for a cross-linkable POSS, obtained by esterification of the hydroxyl groups with methacryloyl chloride. © 2019 Elsevier Ltd

Made available in DSpace on 2021-06-26T07:27:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-05-24 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) A novel silsesquioxane and cobalt nitroprusside compound was prepared from octa(aminopropyl)silsesquioxane, resulting in a nanocomposite (ACCoN), which was then characterized by different spectroscopic techniques. The cyclic voltammograms of the ACCoN-modified graphite paste electrode indicated a redox pair with a formal potential (E-theta ')=0.38 V, assigned to the (CoFe(II))-Fe-(II)(CN)(5)NO/(CoFe(III))-Fe-(II)(CN)(5)NO redox couple. The ACCoN-modified graphite paste electrode was sensitive to isoniazid concentrations, presenting a linear response at a concentration range from 6.0x10(-7) to 1.0x10(-5) mol L-1, with limit of detection and amperometric sensitivity of 5.53x10(-7) mol L-1 and 0.17 A/mol L-1, respectively. Univ Estadual Paulista, Fac Engn Ilha Solteira, Ave Brasil,56, BR-15385000 Ilha Solteira, SP, Brazil Univ Estadual Paulista, Fac Engn Ilha Solteira, Ave Brasil,56, BR-15385000 Ilha Solteira, SP, Brazil FAPESP: 2018/24576-2

[EN] The largely demand in continued security issues makes necessary the development of novel materials with outstanding properties to improve the current detection techniques. In this context, latent fingerprint (LF) by fluorescent labeled materials (FLM) is one of the most attractive personnel identification methodologies. Here, two FLM based on polyhedral oligomeric silsesquioxane (POSS) nanohybrids labeled with dansyl chromophores have been synthesized and fully characterized. Their photophysical properties have confirmed that these materials clearly possess the prime qualifications as suitable LF sensing platforms. In fact, they adequately detect LFs on glassy surface with excellence legibility., Financial support by the Alexander von Humboldt Foundation (Georg Forster Research Fellowship to E.O. Dare), Generalitat Valenciana (CIDEGENT/2018/044) and Universitat Regensburg is gratefully acknowledged. Laboratory assistance from MSc A. Abramov and Dr. B. Maiti (Universitat Regensburg) is deeply acknowledged. D.D.D. thanks the DFG for the Heisenberg Professorship Award and the Spanish Ministry of Science, Innovation and Universities for the Senior Beatriz Galindo Award (Distinguished Researcher; BEAGAL18/00166). D.D.D. thanks NANOtec, INTech, Cabildo de Tenerife and ULL for laboratory facilities.

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Dissertation, RWTH Aachen University, 2021; Aachen : RWTH Aachen University 1 Online-Ressource : Illustrationen (2022). = Dissertation, RWTH Aachen University, 2021, Poly(organo)phosphazenes are macromolecules with alternating phosphorous-nitrogen atoms in their skeleton -with linear (chains) or cyclic (rings) structure- and organic side groups. This thesis investigates the synthesis and properties of cyclomatrixtype polyphosphazenes, starting from hexachlorocyclotriphosphazene N3P3Cl6 (HCCP) or partially substituted HCCP with methoxy-groupsN3P3Cl6-n(OMe)n, and amine functionalized silsesquioxanes. The polycondensation of HCCP with multifunctional amines results in a three dimensional network with high crosslink density. As such, they have found little interest because their intractability and poor solubility [1, 67]. The reduction of reactive chlorine in HCCP via partial substitution by inert groups, provides access to monomers with reduced functionality, suitable for the formation of less branched or even linear cyclomatrix polymers. In this way, novel soluble and tractable partially substituted HCCP with methoxy-groupsN3P3Cl6-n(OMe)n are synthesized by a simple and robust synthesis in Chapter 3.Because in the course of the years strict regulations have emerged regarding the toxicity of flame retardants, halogen-free alternatives have been intensively explored by the scientific community. In the last years, particular interest has raised for polyphosphazenes, due to its hybrid inorganic-organic backbone with high amount of phosphorous and nitrogen-atoms [9, 128] and their flame inhibition properties. Inspired by the actual needs, high thermally stable cyclomatrix poly-(organo)phosphazenes made by precipitation polymerization of N3P3Cl6 or N3P3Cl6-n(OMe)n and silsesquioxane building blockshave been synthesized in Chapter 4.Our contact to textiles is almost everywhere, in clothing, at our living- and working-spaces as well as in transportation. The high specific surface area of synthetic and natural fibers make these materials easy to ignite due to the overall-contact to atmospheric oxygen [63]. Thermal stable polyphosphazene-silsesquioxane cyclo-matrix polymers presented in Chapter 5, retard or completely inhibit cellulose-degradation, due to a synergism between phosphorous and nitrogen as well as the formation of a protective carbonaceous-silica char. The polymers are easily applicable as nanocoatings on cotton fibers in a finishing process and relatively small amounts are needed to induce flame retardation. Chapter 6 summarizes conclusions and gives insights in new properties of organo(cyclo)phosphazenes which have been briefly evaluated within the scope of this work. Furthermore an outlook for future research is presented., Published by RWTH Aachen University, Aachen

Herein, a facile and efficient synthetic route to unique hybrid materials containing polysiloxanes and mono(alkyl)silsesquioxanes as their pendant modifiers (T8@PS) was demonstrated. The idea of this work was to apply the hydrosilylation reaction as a tool for the efficient and selective attachment of mono(alkenyl)substituted silsesquioxanes (differing in the alkenyl chain length, from -vinyl to -dec-9-enyl and types of inert groups iBu, Ph at the inorganic core) onto two polysiloxanes containing various amount of Si-H units. The synthetic protocol, determined and confirmed by FT-IR in situ and NMR analyses, was optimized to ensure complete Si-H consumption along with the avoidance of side-products. A series of 20 new compounds with high yields and complete &beta, addition selectivity was obtained and characterized by spectroscopic methods.

Bifunctional silsesquioxanes create an attractive group of compounds with a wide range of potential applications, and recently they have gained much interest. They are known to be obtained mainly via hydrosilylation, but we disclose novel synthetic protocols based on different but complementary reactions, i.e., cross-metathesis (CM) and silylative coupling (SC). A series of cubic T8 type silsesquioxane derivatives with a broad scope of styryl substituents were synthesized in a one-pot procedure and characterized by spectroscopic and spectrometric methods. All of the new compounds can be obtained in a one-pot manner, which has an attractive impact on the synthetic procedure, as it is economic in terms of the isolation of intermediate products. Additionally, the methodology disclosed here enables the (E)-stereoselective introduction of styrenes derivative to the cubic T8 type core. The presented compounds can be interesting precursors for a further functionalization that may significantly increase the possibility of their application in the design and synthesis of new functional materials.

The present study explores the exploitation of ladder-like polysilsesquioxanes (PSQs) bearing reactive functional groups in conjunction with SiO2 nanoparticles (NPs) to produce UV-curable nanocomposite coatings with increased hydrophobicity and good thermal resistance. In detail, a medium degree regular ladder-like structured poly (methacryloxypropyl) silsesquioxane (LPMASQ) and silica NPs, either naked or functionalized with a methacrylsilane (SiO2@TMMS), were blended and then irradiated in the form of a film. Material characterization evidenced significant modifications of the structural organization of the LPMASQ backbone and, in particular, a rearrangement of the silsesquioxane chains at the interface upon introduction of the functionalized silica NPs. This leads to remarkable thermal resistance and enhanced hydrophobic features in the final nanocomposite. The results suggest that the adopted strategy, in comparison with mostly difficult and expensive surface modification and structuring protocols, may provide tailored functional properties without modifying the surface roughness or the functionalities of silsesquioxanes, but simply tuning their interactions at the hybrid interface with silica fillers.

Creation of nanostructured organo-inorganic materials is one of the promising areas of today. The main problem that arise at using nanofillers is the difficulty of ensuring uniform distribution of the inorganic phase in the polymer matrix. Therefore, it is more rational to create nanoparticles that are able to covalently bind to the polymer matrix.This provides both uniform distribution of the inorganic phase and the combination of phases of different nature. Polyhedral oligomeric silsesquioxanes (POSS) deserve attention in terms of their using as such nanostructuring agents. Today, octohedral oligomeric silsesquioxanes are the most widely used in the series. But their using for creating hybrid materials has difficulties such as high cost, complexity of their synthesis, one type of structuring in systems based on them.From the production point of view mixtures of oligosilsesquioxanes containing the POSS in the structure are more accessible. However, despite significant progress in the synthesis of nanostructured systems based on mixtures of oligosilsesquioxanes, studies of the properties and structure for such systems are virtually absent.The main purpose of the article is researching of the structure of the obtained systems based on oligomeric silsesquioxanes. A mixture of oligomeric silsesquioxanes containing hydroxyl and tertiary amino groups (POSS-C) was synthesized. The structure of the obtained samples was studied by the methods of wide - and low - angle scattering of X - rays. It was found that PU,based on oligoethers and mixtures of POSS, form a completely amorphous structure. This occurs regardless of the type of polymer matrix and morphology.The presence of a mixture of POSS prevents the formation of crystals from the organic phase.It was established that the general amorphism of the fine structure of the studied PU is due to the ability of the mixture of oligosilvesquioxanes to reduce the density of the polymer matrix and the insignificant ability of the mixture of POSS to form crystals and crystallites.ong silicon-containing substances, POSS occupy intermediate position between siloxanes and silicates. On the other hand, they can be attributed to spherical siloxanes, because they consist of multifaceted structures, morphologically equivalent to a sphere. The presence of functional groups allows to get rid of a significant lack of siloxanes (do not form fibers and films) due to their low intermolecular interaction.Sisquioxanes can be processed at lower temperatures, both in pure form and in mixtures. Also they do not contain traces of metals. Systems based on POSS and polymers have synergistic properties. The ability to self-organize of systems based on POSS is very big advantage. This allows to obtain organo-inorganic materials with more perfect structural hierarchy. One of the areas of application of the synthesized crosslinked hybrid organo-inorganic systems is obtaining proton-conducting membranes of hydrogen engines., Створення наноструктурованих органо-неорганічних матеріалів – один з перспективних напрямків сьогодення. Головною проблемою, яка виникає при використанні нанонаповнювачів, це важкість забезпечення рівномірного розподілу неорганічної фази в полімерній матриці. Тому більш раціональним є створення наночасток, які здатні ковалентно зв'язуватися з полімерною матрицею. Це забезпечує як рівномірний розподіл неорганічної фази, так і суміщення фаз різної природи. Поліедральні олігомерні силсесквіоксани (ПОСС) заслуговують уваги з точки зору використання їх в якості таких наноструктуруючих агентів. На сьогодні найуживанішими у своєму ряді є октоедральні олігомерні силсесквіоксани. Але їх використання для створення гібридних матеріалів пов’язано з такими труднощами як велика вартість, складність їх синтезу, один тип структурування в системах на їх основі.Більш доступними, з точки зору одержання, є суміші олігосилсесквіоксанів, що вміщують у своєму складі ПОСС-структури. Разом з тим, не дивлячись на значний прогрес у синтезі наноструктурованих систем на основі сумішей олігосилсесквіоксанів, дослідження властивостей та структури для систем такого типу практично відсутні.Головною метою статті є дослідження структури отриманих систем на основі олігомерних силсесквіоксанів. Синтезовано суміш олігомерних силсесквіоксанів, що містить гідроксильні та третинні аміногрупи (ПОСС-С). Досліджено структуру отриманих зразків методами широко – та малокутового розсіяння рентгенівських променів. Встановлено, що ПУ на основі олігоетерів та сумішей ПОСС формують повністю аморфну структуру. Це відбувається незалежно від типу полімерної матриці та морфології. Наявність суміші ПОСС заважає утворенню кристалів з органічної фази. Встановлено, що загальний аморфізм тонкої структури досліджуваного ПУ зумовлений здатністю суміші олігосилсесквіоксанів знижувати щільність полімерної матриці та незначною здатністю суміші ПОСС створювати кристали та кристаліти.Серед речовин, що містять кремній, ПOСС займають проміжне місце між силоксанами та силікатами. З іншого боку, їх можна віднести до сферичних силоксанів, оскільки вони складаються з багатогранних структур, морфологічно еквівалентних кулі. Завдяки наявності функціональних груп можна позбутися значної нестачі силоксанів (не утворюють волокон і плівок) через їх низьку міжмолекулярну взаємодію. Силсесквіоксани можуть перероблятися при більш низьких температурах, як у чистому вигляді, так і в сумішах, а також вони не містять слідів металів. Системи на основі ПОСС та полімерів мають синергетичні властивості. Здатність до самоорганізації систем на основі ПОСС є дуже великою перевагою. Це дозволяє отримувати органо-неорганічні матеріали з більш досконалою структурною ієрархією. Одним із напрямків застосування синтезованих зшитих гібридних органо-неорганічних систем -отримання протонопровідних мембран водневих двигунів.

International audience; Herein we report the synthesis of a new family of styryl-functionalized polyhedral oligomeric silsesquioxanes (Tn, where n = 8, 10, and 12), in which the organic moiety is linked to all n vertices of the Tn cages via the phenyl ring rather than the vinyl group. In contrast to earlier studies in which the styryl group is linked to the cage via the vinyl moiety, our approach ensures that the vinyl moiety is less sterically hindered and available for postfunctionalization. The functional Tn cages have been characterized by a range of techniques, including single crystal X-ray diffraction, multinuclear solution NMR (1H, 13C, and 29Si), MALDI-MS, and FTIR. The solid-state structure of the T8 compound exhibited two nonequivalent Si8O12 cage atoms, which has not been previously reported in the functionalized T8 system, although all cage atoms in the corresponding T10 and T12 systems were equivalent. In contrast, multinuclear solution NMR data indicated that all cages in the T8 system were equivalent in solution, suggesting that the nonequivalent cage geometries arise in the solid state to optimize the packing of the functionalized cages. These compounds have significant potential for future use in the production of 3D cross-linked polymer networks.

Silsesquioxane-based networks are an important class of materials that have many applications where high thermal/oxidative stability and porosity are needed simultaneously. However, there is a great desire to be able to design these materials for specialized applications in environmental remediation and medicine. To do so requires a simple synthesis method to make materials with expanded functionalities. In this article, we explore the synthesis of R-silsesquioxane-based porous networks by fluoride catalysis containing methyl, phenyl and vinyl corners (R-Si(OEt)3) combined with four different bis-triethoxysilyl cross-linkers (ethyl, ethylene, acetylene and hexyl). Synthesized materials were then analyzed for their porosity, surface area, thermal stability and general structure. We found that when a specified cage corner (i.e., methyl) is compared across all cross-linkers in two different solvent systems (dichloromethane and acetonitrile), pore size distributions are consistent with cross-linker length, pore sizes tended to be larger and &pi, bond-containing cross-linkers reduced overall microporosity. Changing to larger cage corners for each of the cross-linkers tended to show decreases in overall surface area, except when both corners and cross-linkers contained &pi, bonds. These studies will enable further understanding of post-synthesis modifiable silsesquioxane networks.

[EN] Hybrid nanostructures with switchable and reversible "blue-red-green" emission were efficiently synthesized. These nanostructures comprise polyhedral oligomeric silsesquioxanes (POSS) that behave as a nanocage that can be functionalized with terpyridine-based organic ligands, which can be easily complexed with europium (III) ions. The complexes were characterized by UV-Vis and fluorescence spectroscopy and their stoichiometry was also confirmed by H-1 NMR spectroscopy. In the presence of the Eu(III) ions, the octafunctionalized nanocages self-assemble to form 3D architectures that display an intense red-emission, especially in the solid state. The presence of an alkenyl group bridging the inorganic core to the organic moiety was employed to tune the emission properties by trans-cis isomerization of the double bond. In the case of the octafunctionalized nanocages (O-POSS), this isomerization was monitored in the presence of Eu(III) cations and was accompanied by an evident colour change from blue (trans-O-POSS) to red (Eu@trans-O-POSS) and finally to green (cis-O-POSS) as consequence of the release of the metal cations. This behaviour, together with the easy dispersion of the dry powder and the possibility of coating as a film in presence of small amounts of solvent, makes the emissive solid promising for applications in materials science., The authors acknowledge the University of Palermo and the University of Namur. V.C. gratefully acknowledges the University of Palermo and University of Namur for a co-funded PhD fellowship.

Створення наноструктурованих органо-неорганічних матеріалів – один з перспективних напрямків сьогодення. Головною проблемою, яка виникає при використанні нанонаповнювачів, це важкість забезпечення рівномірного розподілу неорганічної фази в полімерній матриці. Тому більш раціональним є створення наночасток, які здатні ковалентно зв'язуватися з полімерною матрицею. Це забезпечує як рівномірний розподіл неорганічної фази, так і суміщення фаз різної природи. Поліедральні олігомерні силсесквіоксани (ПОСС) заслуговують уваги з точки зору використання їх в якості таких наноструктуруючих агентів. На сьогодні найуживанішими у своєму ряді є октоедральні олігомерні силсесквіоксани. Але їх використання для створення гібридних матеріалів пов’язано з такими труднощами як велика вартість, складність їх синтезу, один тип структурування в системах на їх основі. Більш доступними, з точки зору одержання, є суміші олігосилсесквіоксанів, що вміщують у своєму складі ПОСС-структури. Разом з тим, не дивлячись на значний прогрес у синтезі наноструктурованих систем на основі сумішей олігосилсесквіоксанів, дослідження властивостей та структури для систем такого типу практично відсутні. Головною метою статті є дослідження структури отриманих систем на основі олігомерних силсесквіоксанів. Синтезовано суміш олігомерних силсесквіоксанів, що містить гідроксильні та третинні аміногрупи (ПОСС-С). Досліджено структуру отриманих зразків методами широко – та малокутового розсіяння рентгенівських променів. Встановлено, що ПУ на основі олігоетерів та сумішей ПОСС формують повністю аморфну структуру. Це відбувається незалежно від типу полімерної матриці та морфології. Наявність суміші ПОСС заважає утворенню кристалів з органічної фази. Встановлено, що загальний аморфізм тонкої структури досліджуваного ПУ зумовлений здатністю суміші олігосилсесквіоксанів знижувати щільність полімерної матриці та незначною здатністю суміші ПОСС створювати кристали та кристаліти. Серед речовин, що містять кремній, ПOСС займають проміжне місце між силоксанами та силікатами. З іншого боку, їх можна віднести до сферичних силоксанів, оскільки вони складаються з багатогранних структур, морфологічно еквівалентних кулі. Завдяки наявності функціональних груп можна позбутися значної нестачі силоксанів (не утворюють волокон і плівок) через їх низьку міжмолекулярну взаємодію. Силсесквіоксани можуть перероблятися при більш низьких температурах, як у чистому вигляді, так і в сумішах, а також вони не містять слідів металів. Системи на основі ПОСС та полімерів мають синергетичні властивості. Здатність до самоорганізації систем на основі ПОСС є дуже великою перевагою. Це дозволяє отримувати органо-неорганічні матеріали з більш досконалою структурною ієрархією. Одним із напрямків застосування синтезованих зшитих гібридних органо-неорганічних систем -отримання протонопровідних мембран водневих двигунів. Creation of nanostructured organo-inorganic materials is one of the promising areas of today. The main problem that arise at using nanofillers is the difficulty of ensuring uniform distribution of the inorganic phase in the polymer matrix. Therefore, it is more rational to create nanoparticles that are able to covalently bind to the polymer matrix.This provides both uniform distribution of the inorganic phase and the combination of phases of different nature. Polyhedral oligomeric silsesquioxanes (POSS) deserve attention in terms of their using as such nanostructuring agents. Today, octohedral oligomeric silsesquioxanes are the most widely used in the series. But their using for creating hybrid materials has difficulties such as high cost, complexity of their synthesis, one type of structuring in systems based on them.From the production point of view mixtures of oligosilsesquioxanes containing the POSS in the structure are more accessible. However, despite significant progress in the synthesis of nanostructured systems based on mixtures of oligosilsesquioxanes, studies of the properties and structure for such systems are virtually absent.The main purpose of the article is researching of the structure of the obtained systems based on oligomeric silsesquioxanes. A mixture of oligomeric silsesquioxanes containing hydroxyl and tertiary amino groups (POSS-C) was synthesized. The structure of the obtained samples was studied by the methods of wide - and low - angle scattering of X - rays. It was found that PU,based on oligoethers and mixtures of POSS, form a completely amorphous structure. This occurs regardless of the type of polymer matrix and morphology.The presence of a mixture of POSS prevents the formation of crystals from the organic phase.It was established that the general amorphism of the fine structure of the studied PU is due to the ability of the mixture of oligosilvesquioxanes to reduce the density of the polymer matrix and the insignificant ability of the mixture of POSS to form crystals and crystallites. ong silicon-containing substances, POSS occupy intermediate position between siloxanes and silicates. On the other hand, they can be attributed to spherical siloxanes, because they consist of multifaceted structures, morphologically equivalent to a sphere. The presence of functional groups allows to get rid of a significant lack of siloxanes (do not form fibers and films) due to their low intermolecular interaction.Sisquioxanes can be processed at lower temperatures, both in pure form and in mixtures. Also they do not contain traces of metals. Systems based on POSS and polymers have synergistic properties. The ability to self-organize of systems based on POSS is very big advantage. This allows to obtain organo-inorganic materials with more perfect structural hierarchy. One of the areas of application of the synthesized crosslinked hybrid organoinorganic systems is obtaining proton-conducting membranes of hydrogen engines.

The recent demand for fluorescent‐labeled materials (FLMs) in forensic security concepts such as latent fingerprints (LFs) that encode information for anti‐counterfeiting and encryption of confidential data makes necessary the development of building new and innovative materials. Here, novel FLMs based on polyhedral oligomeric silsesquioxanes (POSS) functionalized with fluorophores via “click” reactions have been successfully synthesized and fully characterized. A comprehensive study of their photophysical properties has displayed large Stokes's shift together with good photostability in all cases, fulfilling the fundamental requisites for any legible LF detection on various surfaces. The excellent performance of the hetero‐bifunctional FLM in the visualization of LF is emphasized by their legibility, selectivity, sensitivity and temporal photostability. In this study, development mechanisms have been proposed and the overall concept constitute a novel approach for vis‐à‐vis forensic investigations to trace an individual's identity., A series of fluorescent‐labeled nanohybrids based on polyhedral oligomeric silsesquioxanes (POSS) linked to appropriate fluorophores via “click” chemistry can be used to visualize latent fingerprints on several surfaces, providing reasonable legibility patterns that satisfy the requirements for fingerprinting identification in forensic technology.

In this study, the preparation of polybutadiene/polysilsesquioxane nanocomposites (NCs) having tunable thermomechanical and dielectric properties is reported. This was achieved by using different amounts of a filler consisting of a silsesquioxane with a defined ladder-like molecular structure (LPMASQ) bearing reactive methacrylate functionalities. In detail, solid-state nuclear magnetic resonance (NMR) investigation revealed that an increasing amount of filler leads to a progressive homopolymerization of LPMASQ units resulting in the generation of domains in the composites, which induce a kind of polymer chain confinement in proximity of the hybrid interface. The evolution of the molecular organization of the inorganic nanobuilding blocks as a function of their concentration has been highlighted also by small-angle X-ray scattering (SAXS) experiments. The gradual assembly of LPMASQ units gives rise to peculiar dielectric properties along with enhanced thermal and mechanical stability of the final NCs, thus supplying suitable materials for applications in high performance dielectrics. Furthermore, these outcomes support the idea that a careful control of the molecular architecture and organization of the silsesquioxanes in a polymer matrix allows to simultaneously modulate two or more distinct functional features of polymer NCs

Made available in DSpace on 2018-12-11T17:37:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-06-14 This work describes the organofunctionalization and a complementary characterization and application of an octakis(3-chloropropyl)octasilsesquioxane (1) with 4-Amino-5-Phenyl-4H-[1,2,4]-Triazole-3-Thiol (2). The functionalized silsesquioxane (3) was characterized by nuclear magnetic resonance, X-ray diffraction, transmission electron microscopy and thermogravimetric analysis. After functionalized, the silsesquioxane can interact with copper chloride and subsequently with potassium hexacyanoferrate (III) (4). The hybrid composite formed (4) was characterized by FT-IR and diffuse reflectance. The compound 4 included into a work graphite paste electrode (20% w/w) was examined for chronoamperometric determination of L-Dopamine. The modified graphite paste electrode with compound 4 showed a linear response from 2.5× 10− 5 at 4.0× 10− 4 mol L− 1. The modified graphite paste electrode with 4 showed a detection limit of 2.08× 10− 4 mol L− 1 with a relative standard deviation of ± 2% (n = 3) and amperometric sensitivity of 0.136 A mol L− 1. Departamento de Física e Química Universidade Estadual Paulista “Júlio de Mesquita Filho” – UNESP, Avenida Brasil, 56 Departamento de Engenharia Mecânica Universidade Estadual Paulista “Júlio de Mesquita Filho” – UNESP, Avenida Brasil, 56 Departamento de Física e Química Universidade Estadual Paulista “Júlio de Mesquita Filho” – UNESP, Avenida Brasil, 56 Departamento de Engenharia Mecânica Universidade Estadual Paulista “Júlio de Mesquita Filho” – UNESP, Avenida Brasil, 56

Made available in DSpace on 2018-12-11T17:20:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-05-31 A composite prepared from titanium (IV) silsesquioxane and phosphoric acid (TTiP) was prepared and occluded into the H-FAU zeolite (ZTTiP). The material was chemically modified with nickel and subsequently by potassium hexacyanoferrate (III) (ZTTiPNiH). It was preliminarily characterized by infrared spectroscopy (IR), energy dispersive X-ray spectroscopy (EDS) and cyclic voltammetry (CV). The voltammetric behavior of ZTTipNiH was obtained employing a modified graphite paste electrode (GPE) showing one well-defined redox couple with a formal potential of E(Formula presented.) 0.51V (vs Ag/AgCl(sat)), KCl (3M) (20% w/w; v = 20 mV s− 1; KCl; 1.00 mol L− 1) corresponding to the NiIIFeII(CN)6/NiIIFeIII(CN)6 redox process. After rigorous voltammetric studies, the GPE modified with ZTTiPNiH was applied for facile and rapid detection of sulfite. From the analytical curve, a linear response was obtained in a concentration range of 0.05 to 0.80 mmol L− 1 and a detection limit (3σ) of 0.05 mmol L− 1 with a relative standard deviation of 4.21% (n = 3) and an amperometric sensitivity of 14.42 mA L mol− 1 for sulfite. Departamento de Física e Química Faculdade de Engenharia de Ilha Solteira UNESP - Universidade Estadual Paulista, Av. Brasil Centro, 56 Departamento de Física e Química Faculdade de Engenharia de Ilha Solteira UNESP - Universidade Estadual Paulista, Av. Brasil Centro, 56