Papers by Veronica Brunetti
Journal of Electroanalytical Chemistry, Feb 1, 2008
ABSTRACT The anodic growth of oxide/hydroxide films formed on tin in borate solutions (pH 8.9) ha... more ABSTRACT The anodic growth of oxide/hydroxide films formed on tin in borate solutions (pH 8.9) has been studied. At potentials more positive than −0.2V (SHE), oxide film growth occurs by an activation-controlled ionic condition under the influence of a high electric field across the film according to an exponential law as on valve metals. Optical properties of the anodic oxide films have been obtained by “in situ” ellipsometry. Tin oxide/hydroxide films are practically transparent and highly hydrated. Electrical properties of tin oxide layers have been obtained by electrochemical impedance spectroscopy. Impedance spectra are explained in terms of a simple physical model assuming that oxide layer behaves as an inhomogeneous single-layer film.
Macromolecular Symposia, Mar 31, 2010
Journal of Polymer Science Part A: Polymer Chemistry, 2014
ABSTRACT The synthesis of nanoparticle-cored dendrimers (NCDs) through surface functionalization ... more ABSTRACT The synthesis of nanoparticle-cored dendrimers (NCDs) through surface functionalization of iron oxide nanoparticles (γ-Fe2O3) by combining the conventional silane coupling agent 3-(aminopropyl) triethoxysilane (APS) with dendritic moieties is studied and presented. Much emphasis has been put on the role played by each modifier and how they interact not only between themselves, but also with the dispersing media wherein the resulting NCDs are. As a part of the functionalization, redox-active nitro groups were introduced onto the surface of each synthesized NCD thus making them electrochemically active. Then, the obtained NCDs were immobilized onto glassy carbon electrodes. Both the NCDs and modified electrodes are expected to be eventually exploited in analytical and sensing applications. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014
Polymers, 2012
Dendronization is a synthetic methodology that offers important advantages. The resulting product... more Dendronization is a synthetic methodology that offers important advantages. The resulting products, which are called dendronized materials, present new and specific properties. This review shows numerous examples in which individual dendrons are used as building blocks to prepare more complex arrays via covalent or non-covalent interactions. In particular, it points out how the structural information programmed into the dendritic architecture can be used in the dendronization process to generate nanostructures with specific tailored properties. We emphasize the use of different dendrons, with diverse chemical structure and size, to functionalize diverse substrates like linear polymers, and plane and curved inorganic surfaces. Apart from this, the review also demonstrates that self-assembly represents an ideal approach to create well-defined hyperbranched surfaces and it includes some discussion about the ability of both organic and inorganic building blocks to direct this process.
Materials Science Forum, 1998
The Journal of Physical Chemistry B, 2002
... The STM electrochemical cell was made of Kel-F and consisted of a Ag(111) single crystal as a... more ... The STM electrochemical cell was made of Kel-F and consisted of a Ag(111) single crystal as a working electrode, a large-area platinum counterelectrode, and a palladium/hydrogen reference electrode, although all values of potential (E) in the text are given on the SCE scale. ...
Microscopy and Microanalysis, 2014
Surface topography and work function maps were simultaneously obtained for carbon surfaces modifi... more Surface topography and work function maps were simultaneously obtained for carbon surfaces modified by a dendritic molecule: 3,5-Bis (3,5-dinitrobenzoylamino) benzoic acid. The dendrons were spontaneously assembled onto highly ordered pyrolytic graphite samples, exhibiting an increase in the surface potential. This fact is consistent with the incorporation of an electron-acceptor functional group that remains electroactive on the surface.
Langmuir, 2003
... Verónica Brunetti, Bárbara Blum, Roberto C. Salvarezza, and Alejandro J. Arvia*. Instituto de... more ... Verónica Brunetti, Bárbara Blum, Roberto C. Salvarezza, and Alejandro J. Arvia*. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Universidad Nacional de La Plata - CONICET, Sucursal 4, Casilla de Correo 16, (1900) La Plata, Argentina. ...
Journal of Materials Chemistry, 2012
Dendritic polyglycerol (PG) functionalized surfaces represent a good alternative for preparation ... more Dendritic polyglycerol (PG) functionalized surfaces represent a good alternative for preparation of protein resistant materials, whose versatility can be enhanced by conferring them the ability to bind particular biomolecules of interest to the surface. In this work, PG derivatives bearing disulfide and different loadings of amino moieties (0-14%) were synthesized and attached to gold surfaces. The modified surfaces were characterized by means of infrared reflection adsorption spectroscopy (FT-IRRAS), X-ray photoelectron spectroscopy (XPS), and contact angle measurements. The protein resistance properties of the PG-modified surfaces were evaluated by surface plasmon resonance (SPR) spectroscopy using fibrinogen, albumin, pepsin, and lysozyme as model proteins. The availability and accessibility of the amino groups to bind biomolecules were assessed by fluorescence measurements. This study demonstrates that PG-coated surfaces with amino contents up to 9% still show very good protein resistant properties. At the same time, the amino moieties on the surface are available and reactive for selective ligand attachment. By fluorescence labeled DNA hybridization, the high selectivity of these functional surfaces could be demonstrated.
Journal of Electroanalytical Chemistry, 2008
ABSTRACT The anodic growth of oxide/hydroxide films formed on tin in borate solutions (pH 8.9) ha... more ABSTRACT The anodic growth of oxide/hydroxide films formed on tin in borate solutions (pH 8.9) has been studied. At potentials more positive than −0.2V (SHE), oxide film growth occurs by an activation-controlled ionic condition under the influence of a high electric field across the film according to an exponential law as on valve metals. Optical properties of the anodic oxide films have been obtained by “in situ” ellipsometry. Tin oxide/hydroxide films are practically transparent and highly hydrated. Electrical properties of tin oxide layers have been obtained by electrochemical impedance spectroscopy. Impedance spectra are explained in terms of a simple physical model assuming that oxide layer behaves as an inhomogeneous single-layer film.
Journal of Electroanalytical Chemistry, 1997
It has been shown in previous papers that the hanging meniscus rotating disk (HMRD) follows the L... more It has been shown in previous papers that the hanging meniscus rotating disk (HMRD) follows the Levich closely equation and that it can be used to study the kinetics of simple charge transfer reactions as well as the kinetics of preceding chemical reactions in equilibrium in the bulk electrolyte. In this paper, the applicability of the HMRD to the study of catalytic processes is demonstrated.
Electrochimica Acta, 2014
Electrochimica Acta, 1999
ABSTRACT The anodic behaviour of silver electrodes in aqueous sodium chromate solutions has been ... more ABSTRACT The anodic behaviour of silver electrodes in aqueous sodium chromate solutions has been studied by linear potential sweep voltammetry and potentiostatic current transients. The formation and growth of the passivating Ag2CrO4 film is a complex phenomenon that involves a sequence of several processes.The rate of salt film formation is initially controlled by a three-dimensional progressive nucleation process with diffusion-controlled growth. When surface coverage increases the contribution of the resistance of the layer-pore system is apparent.The induction time obtained in the current transients can be associated with the build-up of a critical concentration of silver ions near the electrode surface to produce the precipitation of the solid material on the electrode.
Electrochimica Acta, 1999
ABSTRACT Silver passivation is studied in sodium chromate aqueous solutions. It is shown that the... more ABSTRACT Silver passivation is studied in sodium chromate aqueous solutions. It is shown that the active–passive transition involves active metal dissolution followed by the precipitation of a poorly-conducting layer of silver chromate that passivates the electrode. The potentiodynamic current–potential behavior is adequately described by using the layer-pore-resistance model (LPRM). The agreement between experimental and theoretical curves is excellent and allows us to demonstrate that, after the first stages that involve active dissolution of silver and nucleation of the film, the growth of the passive layer is mainly controlled by the resistance of the electrolyte in the pores of the layer. After passivation, further growth of the film occurs under diffusion control.
Electrochimica Acta, 2009
Dendritic molecules contain multifunctional groups that can be used to efficiently control the pr... more Dendritic molecules contain multifunctional groups that can be used to efficiently control the properties of an electrode surface. We are developing strategies to generate a highly functionalized surface using multifunctional and rigid dendrons immobilized onto different substrates. In the present work, we explore the immobilization of a dendritic molecule: 3,5-bis(3,5-dinitrobenzoylamino) benzoic acid (D-NO2) onto carbon surfaces showing a simple and
Electrochemistry Communications, 2008
Surface immobilization of dendrons and dendrimers presents an exciting opportunity for creating a... more Surface immobilization of dendrons and dendrimers presents an exciting opportunity for creating a wide variety of functionalized polymeric architectures suitable for the immobilization of biomolecules. Dendritic molecules contain multifunctional groups that can be efficiently modified to control the properties of the resulting polymers. We are developing strategies to generate a highly functionalized surface using multifunctional and rigid dendrons immobilized onto different substrates. In this paper, electrochemical methods and scanning probe microscopy were used to explore the immobilization of a dendritic macromolecule (3,5-bis(3,5-dinitrobenzoylamino)benzoic acid) or (D-NO 2) onto gold electrodes. D-NO 2 adsorbs spontaneously by dipping the metal surface in dendron solution and also via grafting of cystamine covalent attached to gold electrode. Reduction of this layer generates the hydroxylamine product. The resulting redox-active layer exhibits a well-behaved redox response for the adsorbed nitroso/hydroxylamine couple.
Current Organic Chemistry, 2013
Nanoscale, 2010
Polyaniline nanospheres (PANI-NS) prepared by morphological transformation of micelle polymerized... more Polyaniline nanospheres (PANI-NS) prepared by morphological transformation of micelle polymerized camphorsulfonic acid (CSA) doped polyaniline nanotubes (PANI-NT) in the presence of ethylene glycol (EG) have been characterized by X-ray diffraction, atomic force microscopy, transmission electron microscopy, scanning electron microscopy, Fourier transform infra-red and UV-Visible spectroscopy. A PANI-NS (60-80 nm) film deposited onto an indium-tin-oxide (ITO) coated glass plate by the
Nanoscale, Jan 19, 2015
Nanoparticle-cored dendrimers (NCDs) are now offering themselves as versatile carriers because of... more Nanoparticle-cored dendrimers (NCDs) are now offering themselves as versatile carriers because of their colloidal stability, tunable membrane properties and ability to encapsulate or integrate a broad range of drugs and molecules. This kind of hybrid nanocomposite aims to combine the advantages of stimuli-responsive dendritic coatings, in order to regulate the drug release behaviour under different conditions and improve the biocompatibility and in vivo half-time circulation of the inorganic nanoparticles. Size, surface chemistry and shape are key nanocarrier properties to evaluate. Here, we have reviewed the most recent advances of NCDs in drug delivery systems, compared their behaviour with non-dendritic stabilized nanoparticles and highlighted their challenges and promising applications in the future.
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Papers by Veronica Brunetti