Browsing by Author "Morales Morales, Jimmy Alexander"
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Item A Facile Glycerol-Assisted Synthesis of Low-Cu2+-Doped CoFe2O4 for Electrochemical Sensing of Acetaminophen(2023-11) Alfonso González, José Guillermo; Granja Banguera, Claudia Patricia; Morales Morales, Jimmy Alexander; Dector, AndrésThis work devised a simple glycerol-assisted synthesis of a low-Cu2+-doped CoFe2O4 and the electrochemical detection of acetaminophen (AC). During the synthesis, several polyalcohols were tested, indicating the efficiency of glycerin as a cosolvent, aiding in the creation of electrode-modifier nanomaterials. A duration of standing time (eight hours) before calcination produces a decrease in the secondary phase of hematite. The synthesized material was used as an electrode material in the detection of AC. In acidic conditions (pH 2.5), the limit of detection (LOD) was 99.4 nM, while the limit of quantification (LOQ) was found to be (331 nM). The relative standard deviation (RSD), 3.31%,was computed. The enhanced electrocatalytic activity of a low-Cu2+-doped CoFe2O4-modified electrode Cu0.13Co0.87Fe2O4/GCE corresponds extremely well with its resistance Rct, which was determined using the electrochemical impedance spectroscopy (EIS) technique and defined its electron transfer capacity. The possibility of a low-Cu2+-doped CoFe2O4 for the electrochemical sensing of AC in humanurine samples was studied. The recovery rates ranging from 96.5 to 101.0% were obtained. These findings suggested that the Cu0.13Co0.87Fe2O4/GCE sensor has outstanding practicability and could be utilized to detect AC content in real complex biological samples.Item Calificación de un dispositivo de inmersión para así realizar recubrimientos de TiO2/Hidroxiapatita sobre superficies metálicas(Universidad Santiago de Cali, 2019) Martínez Bellaiza, Daniela; Morales Morales, Jimmy Alexander; Castillo Ayala, Jorge EnriqueEl método de inmersión o “Dip-Coating” es utilizado para la obtención de películas delgadas sobre diferentes superficies y con un amplio rango de aplicación; este consiste en la inmersión y posterior extracción de un sustrato dentro de una solución precursora para la formación de la película. En este trabajo se realizó la calificación de un dispositivo de inmersión de bajo costo elaborado en la Universidad Santiago de Cali y se ejecutaron recubrimientos sobre sustratos de acero inoxidable con TiO2/Hidroxiapatita por la técnica de química húmeda. Para la calificación se evaluaron parámetros de velocidad y tiempo de inmersión, abordando la calificación de instalación, desempeño y diseño (IQ, PQ y QD respectivamente); la síntesis de Hidroxiapatita se realizó por precipitación controlada y se analizaron las muestras secas por IR/ATR y TGA-DSC obteniendo unos picos característicos del compuesto y un buen comportamiento térmico, además se analizaron los revestimientos realizados utilizando técnicas espectroscópicas obteniendo los depósitos esperados en los sustratos y obteniendo una relación de Ca/P de 1,57.Item Crecimiento de una barrera electroquímica por la electrolisis oxidativa de 2-aminotiazoles y derivados 4-x-fenil(Universidad Santiago de Cali, 2019) Patiño Izquierdo, José Luis; Morales Morales, Jimmy Alexander; Flórez López, EdwinSe realizó el seguimiento electroquímico de los compuestos 4-(4-X-fenil)-2-aminotiazol [ X = 1a -CH3, 1b -NO2 , 1c 2-amino-5-metil-4-feniltiazol y 1d 5-(4-Bromofenil)-oxazol-2- ylamina] a través de voltamperométrica cíclica utilizando como electrodo de trabajo carbón vítreo, electrodo de referencia Ag/Ag+ y como contra electrodo espiral de platino; se estudió el efecto que producen variables como el electrolito soporte, concentración, velocidad de barrido, sustituyente y temperatura durante la electro-oxidación de cada compuesto. Se evidenció que el tamaño del electrolito soporte influye en los valores de potencial y corriente pico. La velocidad de barrido como la concentración modifican proporcionalmente los valores de corriente pico. Por otra parte, el cambio de temperatura afecta los procesos de transferencia electrónica modificando las señales de oxidación. Se evidenció que un sustituyente electro-donador facilita la oxidación del compuesto y uno electro-atractor la dificulta. Por último, se evidencio durante la electrolisis oxidativa el crecimiento de una barrera electroquímica influenciada por cambios estructurales.Item Electro-oxidación del 2-aminotiazol en agua: un estudio preliminar(Informador Técnico, 2017) Villamarin, Andres Felipe; Morales Morales, Jimmy AlexanderEn este trabajo se realizó el estudio de la oxidación electroquímica del 2-aminotiazol (2AT) en medio acuoso (H2O), se utilizó la técnica de ciclovoltamperometria mediante un sistema de tres electrodos, alambre de platino como electrodo de trabajo (d = 0,5 mm), una malla de platino como contra electrodo y un alambre de plata como seudo referencia. Se observó que el proceso de electro-oxidación (onda Ia) empezó en 0,5V y un pico anódico se presentó alrededor de 0,75V, a diferentes velocidades de barrido de potencial (v = 0,05 - 0,1 Vs-1) la intensidad de la corriente aumento. Una voltamperometria a 25 ciclos, evidenció la disminución en la intensidad de la señal de oxidación característica del grupo amino primario, probablemente debido a la acumulación de estructuras químicas poco reducidas sobre la superficie del electrodo.Item Electrochemical reduction processes on glassy carbon electrode of 2- Amino-4-phenylthiazoles(Journal of Physics: Conference Series, 2018) Morales Morales, Jimmy Alexander; Salazar-Osorio, M.; Florez López, E.In this work the electrochemical reduction of the compounds 2-Amino-4-(4-R-phenyl)thiazoles (1a, R = -H and 1b, R = -NHCOCH3) was performed by cyclic voltammetry in dimethylsulfoxide (DMSO) + 0,1 M tetraethylammonium tetrafluoroborate (TEABF4) and tetrabutylammonium hexafluorophosphate (TBAPF6). Two reduction signal were observed, the Ic wave (EpIc = -2.52 V) and wave IIc (EpIIc = -2.77 V) due to an electron transfer of the electrogenerated product in the Ic wave. The change of substituent influences the electrochemical behaviour, showing that an electrodonating substituent causes a higher energy requirement for the reduction of 1b, which became evident in the more negative potential, with respect to 1a. Additionally, it was observed that the peak potential in the first reduction signal Ic wave shifted to more negative values as the potential sweep rate was higher and this was indicative of an irreversible behaviour. A larger salt such as TBAPF6 causes a decrease in the intensity of peak reduction currents, contrary to what was shown by a smaller salt such as TEABF4. Also for both compounds, the cathodic peak potential of wave Ic and IIc is influenced by the effect of the size of salt used. A smaller salt favoured the electrochemical reduction of both heterocyclic compounds.Item Electroquímica, un enfoque verde para la sociedad del S.XXI(Editorial USC, 2019) Morales Morales, Jimmy Alexander; Amatore, Christian; Feliu, Juan Miguel; González Martínez, Ignacio; Rivera Iturbe, Fernando Felipe; García Ochoa, Esteban Miguel; Torresi, Roberto Manuel; Córdoba Torresi, Susana Inés; Orozco Holguín, Jahir; Torres Palma, Ricardo A.; Loaiza, Oscar Andrés; Calderón, Jorge A.; Meléndez, Ángel M.; Dector, Andrés; Quesada-Plata, Fabián E.; Pimi, Luca; Palma Goyes, Ricardo Enrique; Stiefvater, Robert; Casadiego Leal, Natalia Isabel; de Oliveira Junior, Renato Prado; Salazar Duque, Carlos Alberto;Item A preliminary study of cyclic voltammetry in glassy carbon electrode. Redox Behaviour of 2-Amino-4-phenylthiazoles(Journal of Physics: Conference Series, 2018) Morales Morales, Jimmy Alexander; Rios-Acevedo, J. J.; Flórez-López, EdwinIn this work a voltammetric study of the reduction processes of five substituted 2-Amino-4-(4-X-phenyl) thiazoles (-X = -H, -OCH3, -CH3, -Cl, -NO2) in dimethylsulphoxido was performed. In the potential range considered (-2.0 to -2.9 V vs Ag+/AgCl), one signal (Ic) were detected, which was associated with the electrochemical reduction of the corresponding of the heterocycle compound. The voltammetric analysis at the reduction signal showed that when in-creasing the sweep speed (0.1 < v < 1.0 Vs⁻¹), an oxidation signal associated with the Ic wave was not observed. The linear dependence of the peak current with respect to the root of the velocity of the Ic wave, showed that this was a process controlled by diffusion and showed an apparently irreversible behavior. Peak potential shifted to more negative values as the potential sweep speed was higher; this was indicative of irreversible behavior in this signal. The substitution changes influenced the electrochemical behavior, evidencing that a substituent, as in this case methoxy group compound -OCH3, causes a greater energetic demand for the reduction of the thiazole derivative it becomes evident in the most negative potential, with respect to the derivative without substituent -H. This was new evidence of the behavior electrochemical of 2-Amino-4-(4-X-phenyl) thiazoles derivates which had not been reported for these compounds.Item Study of the electrochemical oxidation of 2-Thiazolamine and 2- Oxazolamine on a platinum wire as working electrode(Journal of Physics: Conference Series, 2018) Morales Morales, Jimmy Alexander; Villamarin, A. F.; Flórez-López, Edwin; Rios-Acevedo, J. J.The electrochemical oxidation of 2-aminothiazole (2AT) and 2-aminooxazole (2AO) was studied by means of the cyclic voltammetry technique (VC), on a Pt wire as working electrode. An anodic wide peak centred at 0.79V was observed and 0.98V (Ia wave) caused by the oxidation of the 2AT and 2AO compounds and the formation of cationic radicals on the clean surface of the electrode, respectively. During the studies of (VC) in a small range of exploration speeds, the oxidation signal increased with the increase in speed and moved to more positive potential values. This dependence of the potential with respect to the potential sweep speed indicated a controlled diffusion of the system of an irreversible nature. At T = 298K, from the electrochemical oxidation of 2 AT, a thin coating film with a light brown color was obtained on the surface of the Pt wire. However, in the electroxidation of 2 AO, that result was not evident. While the 2AT electroxidation product loses conductivity, in the case of the 2AO compound, the electrogenerated product on the surface of the platinum wire maintains the conductive properties.Item Synthesis of TiO2/ZnO/Au for application in a new type of paper-based photo-microfluidic fuel cell using human blood(2023-10) Dector, Andrés; Ovando Medina, Víctor M.; Vera Estrada I.L.; Olivares Ramírez, Juan Manuel; Romero Galarza, Adolfo; Antonio Carmona, Iveth D.; Morales Morales, Jimmy Alexander; García Rodríguez, Francisco G.; Álvarez Rodríguez, Edder H.The use of microfluidic fuel cells (μFCs) as power sources in the development of non-implantable biomedical devices, such as patch sensors, could be broadened with the use of physiological fluids as fuels and the use of low-cost materials. In this work, we report the evaluation of a paper-based photo-μFC working with human blood as fuel, and we implement a nanocomposite as anode that presents photoactivity under visible light. The electrocatalyst was synthesized using Zn(NO3)2 and TiCl4 as precursors of the ZnO and the TiO2, respectively, which were coated with Au nanoparticles. It was demonstrated that ZnO and TiO2 nanoparticles consisted of crystals with wurtzite and anatase phases, with average sizes of 26.6 and 19.5 nm, respectively, and the TiO2/ZnO/Au nanocomposite presents 2.62 eV of band gap energy, demonstrating its photoactivity under visible light irradiation. The photocatalyst was tested as photoanode in half-cell for glucose oxidation in aqueous solutions, under illumination and dark conditions, showing characteristics peaks of glucose oxidation in both cases, but higher current was generated under illumination. Finally, we present the implementation of this anode and the construction of a paper-based photo-μFC using human blood as fuel; its performance was evaluated under visible light irradiations and in the dark. The results show a better performance under illumination with voltage, current, and power density values of 0.95 V, 1.2 mA cm−2, and 0.458 mW/cm2, respectively, compared to the corresponding values of 0.8 V, 0.96 mA cm−2, and 0.274 mW/cm2 in dark conditions.