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Item type:Publication, The interaction of metallic ions onto activated carbon surface using computational chemistry software(SAGE Publishing, 2020-07-01)Activated carbon was prepared from the seeds of aguaje palm ( Mauritia flexuosa L.f.) by a chemical activation with phosphoric acid. This activated carbon was used for adsorbing metal ions: Pb(II), Cd(II), and Cr(III). To understand the mechanism of adsorption of these heavy metals (Cr, Cd, and Pb), the activated carbon surface was oxidized with nitric acid (1 M) increasing the oxygenated surface groups showing an increasing in their adsorption capacities of these metals. The oxidized activated carbon slightly increased the maximum adsorption capacity to 5–7%. The order of adsorption for unoxidized and oxidized activated carbons was Pb> Cd> Cr. This experimental information was corroborated by molecular modeling program Hyperchem 8 based adsorption mainly on two factors: the electron density and orbitals—highest occupied molecular orbital and lowest unoccupied molecular orbital.Activated carbons were characterized by adsorption/desorption of N 2 , obtaining an increase of microporous surface area for oxidized activated carbon. An increase of surface acidity and a reduction of isoelectric points were observed in oxidized activated carbon. According to these results, the adsorption of metal ions is favored in contact with an oxidized activated carbon, which has more amount of phenolic and carboxylic functional groups. Similarly, decreasing the isoelectric point indicates that the surface has a higher negative charge. The surface information was corroborated by Hyperchem, which indicates that the surface of the oxidized activated carbon has a higher electron density, indicating a larger amount of electrons on its surface, which means the surface of oxidized activated carbon charges negatively and thereby attracts metal ions. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Low viscosity alkyd resins based on trimethylolpropane and Peruvian oil(Springer Science and Business Media B.V., 2021-06-01)The high-unsaturated fatty acid content of Sacha inchi oil (SIO), a perennial plant originally from Peru, has turned it into a potential raw material for the production of alkyd resins. In this study, different proportions of multifunctional polyols were used to prepare air-drying resins. Physicochemical characteristics (acid value, viscosity, colour, density, drying time, and hardness) of alkyds were evaluated. Moreover, FT-IR, TG–DTA, 1H-NMR and 13C-NMR characterization techniques were used. SIO-based alkyd resins prepared with trimethylolpropane exhibited low viscosities, suitable for preparing more manageable high solids protective coatings. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Use of multivariate analysis for determining the most influential physicochemical properties of activated carbon in cadmium removal(Emerald Group Holdings Ltd., 2022-04-19)The goal of this paper is to model the activated carbon adsorption capacity of cadmium using a polynomial regression model. The properties that influence the removal of heavy metals by activated carbon must be taken into consideration in order to synthesize materials specific to the characteristics of the pollutant. Design/methodology/approach: Multivariable analysis applications allow a comprehensive description of the relationship between activated carbon surface properties and heavy metal adsorption. Findings: The authors use a second-grade polynomial regression model to determine the influence of porosity and surface acidity in cadmium adsorption by activated carbon. Originality/value: The authors propose a statistic analysis to correlate the carbon properties with its cadmium adsorption capacity. Model coefficient analysis will give a better comprehension of the influence of activated carbon porosity and surface acidity of cadmium removal. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Microwave-assisted synthesis of alkyd resins using response surface methodology(Elsevier BV, 2022-11-28)Long alkyd resins for artistic applications were prepared by microwave synthesis of high-unsaturated vegetable oils. In this work, response surface method using split-plot optimal design was applied to optimize alkyd resin's acid value. Oil vegetable source (Sacha inchi and Linseed oil), temperature (200–240 °C), reaction time (4–12 min), and benzoic acid were evaluated as independent variables. Long alkyds resins with lower acid value considered optimal were characterized by FTIR and 1H-RMN techniques. Physicochemical properties, like color, viscosity, and drying time were assessed as well. Synthesis of alkyd resins from sacha inchi oil required less time and energy in comparison with linseed oil ones. Alkyd resins prepared with Sacha inchi oil for 210 °C and 12 min using 11.67 kJ/g at esterification stage provided a lower acid value (14 mgKOH/g), viscosity (W-X bubble Gardner), and Gardner scale color (11) in comparison with linseed oil. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Alkyds with Artistic Applications Based on Drying Oils, Multifunctional Polyalcohols and Different Polybasic Acids(John Wiley and Sons Inc, 2023-04-20)Today's requirements in the art field have challenged researchers to create artistic paintings with attractive appearance and long-term color stability. Alkyd-based art mediums have become an important group in the art field, because of their similar characteristics to traditional oils and exceptional drying properties. In this work, high solid alkyd-based art mediums have been synthesized by the monoglyceride and acidolysis processes. Multifunctional polyols and high unsaturated fatty acid sources were compared and used for alkyd synthesis. The use of a non-traditional oil of Peruvian origin is proposed. Resins have been characterized according to their physicochemical (acid number, viscosity, color and density) and drying properties. Drying tendencies were verified with the use of quartz crystal microbalance. Also, the behavior of the art mediums mixed with commercial oil paintings and a dry pigment, have also been evaluated. Results indicate that resins containing the polyol with the highest functionality are more viscous and have fewer tendencies to yellowing, while non-traditional Peruvian oil is the best option for creating light-colored art mediums. Alkyd mediums prepared by the monoglyceride method gave to oil paintings better characteristics and drying behavior on canvas. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Optimization and greenness evaluation of extraction methods of bioactive compounds from cocoa bean shells (Theobroma cacao L.)(Royal Society of Chemistry, 2026-01-01)Green extraction from cocoa bean shells (CBS): optimization and comparison of ultrasound-assisted (UAE) and microwave-assisted (MAE) technologies for recovering bioactive compounds. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Microwave-assisted modification of a solid epoxy resin with a Peruvian oil(Elsevier BV, 2025-09-01)A solid epoxy resin was modified with drying vegetable oils via microwave heating to produce one-component epoxy ester resins. These hybrid bio-based resins have an epoxy network that cures at room temperature due to the auto-oxidative capacity of unsaturated fatty acid chains. The influence of the fatty acid source, temperature, and reaction time on viscosity was evaluated using a response surface design. Structure (Fourier transform infrared (FTIR) spectroscopy and proton nuclear magnetic resonance ( 1 H NMR)), drying behavior, thermal stability (thermogravimetry/ differential thermal analysis (TG/DTG)), and molecular weight distribution (gel permeation chromatography (GPC)) of selected resins were also studied. Paints prepared with representative epoxy ester resins were analyzed to compare the effect of the fatty acid source on anticorrosive properties by electrochemical impedance and salt spray tests. The design of experiments simplified the selection of synthesis conditions to obtain optimal resin film properties. Microwaved-synthesized epoxy ester resins prepared with Peruvian oil are potential raw materials for developing functional anticorrosive paints, as they provide the best corrosion resistance . Its high unsaturation content gives sacha inchi oil the curing properties needed to replace linseed oil in the coatings industry .1