Papers by Mariana Revuelta
DOAJ (DOAJ: Directory of Open Access Journals), 2011
Self-assembled hybrid organo-silica sol-gel materials are rapidly expanding for new and novel app... more Self-assembled hybrid organo-silica sol-gel materials are rapidly expanding for new and novel applications. The microporous solid silica matrix was used as a carrier for the controlled release of ascorbic acid (AA), selected as cargo molecule. One-step synthesis procedure was optimized for the preparation of silica-molecule composites by using tetraethoxysilane and methyltrimethoxysilane as precursors. The hydrophobic silica xerogel matrices were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction. Specific surface area and porosity parameters were determined by Brunauer-Emmett-Teller (BET) technique and the matrix surface morphology by scanning electron microscopy (SEM). The observed release pattern could be interesting for the development of AA-fortified food and for use in food packaging.
El objetivo del trabajo fue evaluar el empleo de microesferas de sílice mesoporosa MCM-41 como so... more El objetivo del trabajo fue evaluar el empleo de microesferas de sílice mesoporosa MCM-41 como soporte del carvacrol para el desarrollo de pinturas antifúngicas de base agua. Las MCM-41 se sintetizaron mediante la técnica de Liu et al., fundada en el uso de ligandos de silicatos como precursores inorgánicos hidrolíticos y tensioactivos como especies porógenas. La carga del carvacrol en MCM-41 se realizó por impregnación y posterior adsorción de vapor en un vial herméticamente cerrado incubado a 40 º C durante 24 horas. Se formularon y prepararon pinturas base acuosa en las que se incorporó como aditivo, 2% p/p, microesferas impregnadas con carvacrol (Pintura A), una pintura con microesferas sin impregnar (Pintura B), una pintura con carvacrol 2% p/p en forma libre (Pintura C) y otra pintura control sin microesferas y sin carvacrol (Pintura D). Se pintaron paneles de yeso y se realizaron ensayos de bioresistencia de la película seca frente al hongo Aspergillus sp. Al finalizar el ensayo se realizó una inspección visual y observaciones mediante microscopia electrónica de barrido (MEB). Los resultados mostraron que los paneles con la Pintura C y D se encontraban cubiertos con crecimiento fúngico. El porcentaje de cobertura fue alrededor de un 30 a 70% para la pintura C y un porcentaje mayor a 70% para la pintura D. Las pinturas A y B no presentaron crecimiento a simple vista. Las observaciones en MEB mostraron diferencias entre estas dos últimas, exponiendo crecimiento en el caso de la Pintura B. Estos resultados indican que la incorporación de las microesferas de por sí tienen un efecto biocida, debido muy probablemente al tensioactivo utilizado para su síntesis. A su vez, las micrografías MEB revelan que la impregnación del carvacrol en la sílice mejora aún más el efecto biocida de las microesferas. Este estudio demuestra que las microesferas de sílica mesoporosa MCM-41 podrían ser una alternativa como soporte para la carga del carvacrol en pinturas con actividad antifúngica.
Proyectos de investigación en los cuales colabora: a) Pinturas Higiénicas b) Pintur... more Proyectos de investigación en los cuales colabora: a) Pinturas Higiénicas b) Pinturas Especiale
La protección contra la corrosión utilizando nanocontenedores cargados con inhibidores ecológicos... more La protección contra la corrosión utilizando nanocontenedores cargados con inhibidores ecológicos es un enfoque prometedor prometedor. El objetivo de este trabajo es evaluar el comportamiento anticorrosivo de pigmentos inhibidores ecológicos, los cuales están basados en nanoarcillas, haloisitas, cargadas con iones pasivantes. Las propiedades de inhibición de la corrosión de los pigmentos diseñados fueron evaluadas mediante técnicas electroquímicas. Los resultados demostraron que las nanoarcillas conteniendo inhibidores pasivantes se podrían emplear como un potencial reemplazo del fosfato de zinc para la formulación de recubrimientos anticorrosivos.Centro de Investigación y Desarrollo en Tecnología de Pintura
Simposio Internacional sobre Materiales Lignocelulósicos y XIII Congreso Internacional en Ciencia y Tecnología de Metalurgia y Materiales (SAM/CONAMET) (Puerto Iguazú, 20 al 23 de agosto de 2013), 2013
El objetivo de este trabajo fue estudiar zeolitas naturales, modificadas por intercambio iónico c... more El objetivo de este trabajo fue estudiar zeolitas naturales, modificadas por intercambio iónico con iones Ce(III), como pigmentos anticorrosivos para reemplazar total o parcialmente al fosfato de cinc, cuestionado por su impacto negativo en el ambiente. Las zeolitas modificadas fueron caracterizadas mediante microscopía electrónica de barrido (MEB) y espectroscopia infrarroja por transformada de Fourier. La capacidad de intercambio se determinó por una técnica gravimétrica. Las propiedades funcionales de los pigmentos fueron evaluadas mediante técnicas electroquímicas y la película formada sobre el acero observada mediante MEB y caracterizada por espectroscopía de rayos X dispersiva en energía. Algunas zeolitas modificadas se emplearon en la formulación de pinturas evaluándose su capacidad protectora mediante potencial de corrosión, espectroscopia de impedancia electroquímica, ruido electroquímico y ensayos de cámaras de niebla salina y de humedad. De acuerdo a los resultados obtenidos, hasta 2/3 del contenido de fosfato de cinc podrían ser reemplazados por las zeolitas modificadas.
European Corrosion Congress (EUROCORR 2013) (Estoril, Portugal, 1º al 5 de septiembre de 2013), 2013
Progress in Organic Coatings, 2021
There is a great concern about the indoor microbial colonization especially in places that should... more There is a great concern about the indoor microbial colonization especially in places that should have high standards of environmental hygiene. Besides, due it shortened the useful life of the coating by discoloration and degradation. Currently this is a problem that must be solved in an innovative and eco-friendly way. In this sense, the aim of the work was to develop a green waterborne paint formulated with microcapsules containing essentials oil as biocide agent. This novel hygienic coating would be applied as to protect indoor surfaces from fungi. The microcapsules were synthesized by interfacial polymerization. Melamine-formaldehyde (MF) resin was used for the microcapsule shell wall, and Lavandin and Tea Tree essential oils (EOs) as core materials. The synthesized microcapsules were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and particle size analysis. Preparation of acrylic waterborne paint was performed and the microcapsules MF-EOs were dispersed into the original paint just before application on commercial gypsum boards. The stability of the MF-EOs in the paint was successfully achieved. Two control paints were used, one containing EOs in free form and other without biocide. The effectiveness of the microcapsules into paint film against spore suspension of Aspergillus fumigatus was evaluated by seeding the fungus on the painted surface. The fungal growth was evaluated according to ASTM D5590 standard specification. The score obtained from MF-Lavandin paint indicates just a trace growth onto the painted surface (<10 %). On the control and MF-Tea tree paints the growth was 70 %. The MF-Lavandin showed a high inhibition activity against fungal in the dry paint film compared with the one containing free form EOs paint.
5th International Symposium on Environmental Biotechnology and Engineering (5ISEBE) (National University of San Martín, San Martín, July 25th-29th, 2016), 2016
The challenges for developing new materials are accomplishing more functionality with less materi... more The challenges for developing new materials are accomplishing more functionality with less material due to the increasing efficiencies of the smart approaches. In this sense, the coating technology based on the incorporation of microcapsules has emerged recently as a strategy in the advance of protective and functional materials, promising an environmentally friendly approach. Microbial colonization of painted surfaces is a major concern because it shortened the useful life of the coating by discoloration and degradation. Besides there is a great concern about the indoor microbial colonization especially in places that should have high standards of environmental hygiene as in the food industry and those related to human health-care. The aim of this work is to develop a novel green antifungal water-borne paint formulated with melamine-formaldehyde (MF) microcapsules containing essentials oil as biocide agent. The microcapsules were synthesized by interfacial polymerization. Melamine-formaldehyde resin was used for the microcapsule shell wall, and two different essential oils (EOs) as core materials. The EOs studied were Tea Tree and Lavandin Abrialis. Microcapsule morphology was examined by Field-Emission Scanning Electron Microscopy (FE-SEM), while their size distributions were determined by light diffraction (LD). Microcapsule composition (shell and core) was analyzed by FTIR-ATR spectroscopy. Preparation of acrylic water-borne paint was done in a high speed disperser. The microcapsules (MF-Tea tree and MF-Lavandin) were incorporated into the original paint just before used, at 6% by weight of the total paint composition. As negative control a paint without biocide was used. The effectiveness of these microcapsules on paint film was evaluated by plaque inhibition assay. Commercial gypsum boards were used as substrate. Each painted panel was inoculated with 100 µl of the spore suspension of Aspergillus sp. and kept in a culture chamber at 86% relative humidity for 4 weeks. The fungal growth was estimated as a percentage of coverage onto the surface and scored according to ASTM D5590 standard specification. The results obtained in antifungal assay on paint film were promising. According to ASTM D5590, the score obtained by MF-lavandin paint was 1, which indicate just a trace growth onto the painted surface (<10%). On the other hand, the control and MF-Tea tree paints obtained the same score: 4 points, the highest qualification (fungal growth >70%). Comparing those results, it can be seen that
Food Technology and Biotechnology, 2011
Self-assembled hybrid organo-silica sol-gel materials are rapidly expanding for newand novel appl... more Self-assembled hybrid organo-silica sol-gel materials are rapidly expanding for newand novel applications. The microporous solid silica matrix was used as a carrier for the controlled release of ascorbic acid (AA), selected as cargo molecule. One-step synthesis procedure was optimized for the preparation of silica–molecule composites by using tetraethoxysilane and methyltrimethoxysilane as precursors. The hydrophobic silica xerogel matrices were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction. Specific surface area and porosity parameters were determined by Brunauer-Emmett-Teller (BET) technique and the matrix surface morphology by scanning electron microscopy (SEM). The observed release pattern could be interesting for the development of AA-fortified food and for use in food packaging.
A wide variety of inhibitive pigments is now being offered as possible alternatives to chromate a... more A wide variety of inhibitive pigments is now being offered as possible alternatives to chromate and lead compounds for painted metals protection. Unfortunately, the most wide spread of these substitute pigments, zinc phosphate, has, at present, raised some environmental concern because phosphate causes the eutrophication of water courses and zinc itself is toxic. The aim of this research was to study the anticorrosive performance of a mixture consisting of zinc phosphate, modified zeolite and clay (bentonite) in order to diminish phosphate content in paints. The zeolite and the clay were exchanged with La(III) ions, as inorganic green inhibitor. In the first step, the anticorrosion protection by La(III) ions in solution was assessed by electrochemical tests. In the second step, an epoxy-polyamide paint formulated with the pigment mixture applied on galvanized panels was studied by salt spray test and electrochemical noise measurements (ENM). The results showed that it was possible to replace part of the zinc phosphate content in the paint with the exchanged zeolite and the clay.
Fil: Roselli, Sol Natacha. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina
El objetivo del trabajo fue evaluar el empleo de microesferas de sílice mesoporosa MCM-41 como so... more El objetivo del trabajo fue evaluar el empleo de microesferas de sílice mesoporosa MCM-41 como soporte del carvacrol para el desarrollo de pinturas antifúngicas de base agua. Las MCM-41 se sintetizaron mediante la técnica de Liu et al., fundada en el uso de ligandos de silicatos como precursores inorgánicos hidrolíticos y tensioactivos como especies porógenas. La carga del carvacrol en MCM-41 se realizó por impregnación y posterior adsorción de vapor en un vial herméticamente cerrado incubado a 40 º C durante 24 horas. Se formularon y prepararon pinturas base acuosa en las que se incorporó como aditivo, 2% p/p, microesferas impregnadas con carvacrol (Pintura A), una pintura con microesferas sin impregnar (Pintura B), una pintura con carvacrol 2% p/p en forma libre (Pintura C) y otra pintura control sin microesferas y sin carvacrol (Pintura D). Se pintaron paneles de yeso y se realizaron ensayos de bioresistencia de la película seca frente al hongo Aspergillus sp. Al finalizar el ensayo se realizó una inspección visual y observaciones mediante microscopia electrónica de barrido (MEB). Los resultados mostraron que los paneles con la Pintura C y D se encontraban cubiertos con crecimiento fúngico. El porcentaje de cobertura fue alrededor de un 30 a 70% para la pintura C y un porcentaje mayor a 70% para la pintura D. Las pinturas A y B no presentaron crecimiento a simple vista. Las observaciones en MEB mostraron diferencias entre estas dos últimas, exponiendo crecimiento en el caso de la Pintura B. Estos resultados indican que la incorporación de las microesferas de por sí tienen un efecto biocida, debido muy probablemente al tensioactivo utilizado para su síntesis. A su vez, las micrografías MEB revelan que la impregnación del carvacrol en la sílice mejora aún más el efecto biocida de las microesferas. Este estudio demuestra que las microesferas de sílica mesoporosa MCM-41 podrían ser una alternativa como soporte para la carga del carvacrol en pinturas con actividad antifúngica.
Reactive and Functional Polymers, 2016
Six pectins with 35% to 91% methoxylation degree were purified and characterized to encapsulate C... more Six pectins with 35% to 91% methoxylation degree were purified and characterized to encapsulate Crystal Violet (CV). Amidated low methoxylated pectin (ALMP) was selected based on microsphere morphologies, aqueous solubility, viscosity and the effect of calcium concentration. Pectin microspheres were stabilized with Arabic gum (AG) and optimized according to the loading. Microspheres composed of 2.0% ALMP-1.0% AG crosslinked with 450 mM calcium(II) were able to encapsulate 217 ± 2 μM CV. Optical microscopy of the gels revealed spheroid microspheres with 250 ± 50 μm diameter containing homogenous CV distribution. Dried microspheres observed by SEM and epifluorescence showed a highly shrinkable matrix keeping the spheroidal morphology. Low relative viscosity of the ALMP-AG-CV solutions was found compared to ALMP and ALMP-AG. The Young moduli (60-80 Pa) of ALMP-AG microspheres by texturometric analysis indicated that the CV could interfere with the gel crosslinking. Raman spectroscopy analysis suggested some interaction of CV nucleophilic center within the matrix. FTIR of the matrix showed largest shifts in the carbonyl and carboxylate groups probably associated to H-bridges. CV stability studies performed on ALMP-AG microspheres, synthetized from polymer solutions with pH values above and below pectin pKa and showed faster CV release rates in presence of ionic strength.
Food Technology and …, 2011
Self-assembled hybrid organo-silica sol-gel materials are rapidly expanding for new and novel app... more Self-assembled hybrid organo-silica sol-gel materials are rapidly expanding for new and novel applications. The microporous solid silica matrix was used as a carrier for the controlled release of ascorbic acid (AA), selected as cargo molecule. One-step synthesis procedure was optimized for the preparation of silica-molecule composites by using tetraethoxysilane and methyltrimethoxysilane as precursors. The hydrophobic silica xerogel matrices were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction. Specific surface area and porosity parameters were determined by Brunauer-Emmett-Teller (BET) technique and the matrix surface morphology by scanning electron microscopy (SEM). The observed release pattern could be interesting for the development of AA-fortified food and for use in food packaging.
Corrosion Reviews
The aim of this paper was to evaluate the performance of two different modified zeolitic minerals... more The aim of this paper was to evaluate the performance of two different modified zeolitic minerals as anticorrosion pigments in order to reduce or eliminate zinc phosphate in paints. In the first stage, the selected minerals were characterized and modified with cerium ions to obtain the anticorrosion pigments. Their inhibitive properties were evaluated by means of electrochemical techniques (corrosion potential measurements and polarization curves) employing a steel electrode immersed in the pigments suspensions. In the second stage, solvent-borne paints, with 30% by volume of the anticorrosion pigment, with respect of the total pigment content, were formulated. The performance of the resulting paints was assessed by accelerated (salt spray and humidity chambers) and electrochemical tests (corrosion potential measurements and electrochemical impedance spectroscopy) and compared with that of a control paint with 30% by volume of zinc phosphate. Results obtained in this research sugges...
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Papers by Mariana Revuelta