Química
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Browsing Química by Author "Ávila Torres, Yenny Patricia (Directora)"
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Item Caracterización térmica y espectroscópica de cenizas obtenidas de residuos de la industria papelera y su comportamiento adsortivo frente al colorante naranja de metilo(Universidad Santiago de Cali, 2021) López Estrada, Carolina; Ávila Torres, Yenny Patricia (Directora)In this project, the adsorption capacities of a waste material, obtained from the combustion of coal and biomass in the boilers of the paper industry, were studied in a preliminary way at the physicochemical level; against an anionic and cationic dye; methyl orange. In this sense, it was necessary to carry out the structural and spectroscopic characterization of the residue using the following techniques: thermogravimetry and differential scanning calorimetry, IR and NIR spectroscopy, atomic absorption showing inorganic composition made up of: Si, Al, Fe, Mg, Mn, Cu, Fe and Zn and finally the physicochemical characterization was carried out from the PZC potential, establishing the adsorption model of the material with residual positive charge and its possible utility in the removal of contaminants in the anionic dye industry.Item Degradación de Ampicilina, Catecol y el colorante naranja II, a partir de residuos de CdS obtenidos de prácticas convencionales de Química Inorgánica(Universidad Santiago de Cali, 2019) Vidal Ruíz, Victor Alfonso; Ávila Torres, Yenny Patricia (Directora)The elimination of orange dye, catechol and ampicillin (products present in waste from practical work of organic chemistry and biochemistry), was carried out with cadmium sulfide (CdS). This inorganic material was obtained from of residues of acid- base Pearson's practices in the laboratories of inorganic and analytical chemistry. Cadmium sulfide is a semiconductor with a GAP 2.4-2.6 ; which allows its use as a photocatalyst in the visible region and enhances its application in the degradation of organic matter. An important source of this type of materials are the conventional practices at the laboratory level, where it is possible to obtain residues such as PbS and CdS; which are generally underutilized. In this article, the impure CdS residue was purified and characterized as was reported, previously. Subsequently, organic labs and has obtained the best parameters at pH neutral for the elimination of orange II. This behavior was compared with the transformation of catechol and ampicillin as neutral and zwitterion molecules. H2O2, KI and acetonitrile as solvent, were added in to order to evaluate synergistic effects and establish the role of the semiconductor, (huecos) h+ and OH-. This work is a contribution to the reuse of waste in teaching laboratories, which promote the recirculation water contaminated with this type of organic compounds and allows for the student to design experimental protocols that allow him to use two types of organic and inorganic waste.Item Efectos electrónicos de metales de transición sobre la actividad fotocatalítica de ferratos con actividad bactericida(Universidad Santiago de Cali, 2021) Zúñiga Espitia, Heidi Vanessa; Gutiérrez Moreno, Nini Johanna (Directora); Ávila Torres, Yenny Patricia (Directora)The progressive increasing in mortality and morbidity from antimicrobial resistance (AMR), is one of the most burdensome problems for public health worldwide. Microorganisms, such as Grampositive Staphylococcus aureus and Gramnegative Escherichia coli, have had incidence in part of the population attended in medical establishments providing medical services in Cali. In this context, the present project proposes the synthesis of metal oxides (MO2 y MFe2O4) by means of laser ablation and hydrothermal techniques. Optical properties are studied using electronic spectroscopy (UV-Vis) and is consistent with the morphology by transmission electron microscopy (TEM). The results obtained in the characterization showed that they are indeed semiconductors with forbidden gaps that 3.3 eV TiO2, 2.9 eV TiFe2O4, 2.8 eV ZnFe2O4 and their sizes belong to nanoparticles range the from 6 - 11 nm to 30 - 40 nm. In the case of photoactivated antibacterial activity against the mentioned strains, it was found that the most adequate disinfection mechanism to eliminate the suspended S. aureus microorganisms was achieved through direct oxidation in the semiconductor gap (h+); while with the E. coli strains was by the hydroxyl radical.Item Evaluación de las propiedades fisicoquímicas del almidón termoplástico en presencia de ácido láctico(Universidad Santiago de Cali, 2019) Pastrana Gutiérrez, Isabel; Ávila Torres, Yenny Patricia (Directora); Caicedo Cano, Carolina (Directora)The thermoplastic starch was modified with lactic acid in the molten state, using two types of starches (achira and potato) and two different plasticizers, glycerol and sorbitol. These components were used in a 70:30 ratio (starch: plasticizer) and the addition of acidic agent was carried out in portions of 3, 6 and 9% by weight. These mixtures were obtained in a torque rheometer at 130 ° C for 10 min. The thermal characterization performed showed greater stability for the samples of TPSL> TPS, the values in the temperature of degradation varied between 230 ° C to 280 ° C, while for the thermal transitions corresponding to the temperature of gelatinization and fusion they showed a decrease in the crystallinity for the samples with 6% oleic acid, these results were consistent with the morphological analysis. The results derived from the oscillatory rheological analysis had a viscous behavior in the TPS samples, while the presence of the acid generated viscous to elastic transitions. Finally, a reduction in the hydrophilicity of the modified TPS was evidenced because some of the samples increased the value of the contact angle by up to ~ 46%.Item Polímeros de coordinación de Plata(l), Cobalto(II) y Manganeso(II) con PVA inmovilizado en quitosano depositado en aluminio y vidrio erosionado(Universidad Santiago de Cali, 2019) Díaz Canchimbo, Viviana Maria; Ávila Torres, Yenny Patricia (Directora); Caicedo Cano, Carolina (Directora)The aim of this research work was the development of low and medium molecular weight chitosan (Q) membranes embedded with polyvinyl alcohol, which were enriched with the metal ions of: copper (II), cobalt (II), manganese ( II) and silver (I) as new bactericidal materials. The method used was electrospinning, establishing optimal deposit conditions (DC 11 cm, VB 0.01 mL / hr, V 16 Kv, T 70 min and 16% PVA) on two aluminum surfaces and eroded glass. The antibacterial activity was carried out against Staphylococcus aureus and Eschericia Coli by comparing the activity in solution and its corresponding supported membrane. The method used was Kirby - Bauer modified discs, implementing as positive controls amoxicillin at 25000 ppm and the metal salts at 50000 ppm by each transition metals. The preliminary results show bactericidal and bacteriostatic activity mediated by the nature of the metal ion, further studies are proposed in order to understand the diffusion process and the effect on the stability of the coordination polymers with respect to biological activity.Item Síntesis y caracterización de compuestos de coordinación, a partir de un ligando ditiocarbamato derivado de fenilendiamina con posible actividad biológica(Universidad Santiago de Cali, 2023) Mosquera Olano, Maria Camila; Flórez López, Edwin (Director); Ávila Torres, Yenny Patricia (Directora)In the present research work, the synthesis of three coordination compounds was carried out, whose ligand was synthesized from m-phenylenediamine and benzaldehyde, giving rise to the secondary amine N,Ndibenzylbenzene-1,3-diamine. The formation of the amine was verified through infrared spectroscopy, in which the spectrum obtained presented the characteristic signals of the proposed amine such as 𝑣(N-H) stretching and symmetric and asymmetric stretching of the benzylic carbon 𝑣(C-H). It was also characterized by mass spectrometry, which allowed us to observe the mass of the molecular ion of 288 m/z and the characteristic fragmentations of the proposed molecule. Likewise, to complement the characterization, the amine was analyzed by 1H and 13C NMR spectroscopy, whose spectra evidence the presence of the carbons and hydrogens of the proposed structure. Once the amine was characterized, the in situ synthesis of the coordination compounds was carried out, forming the ligand N,N-dibenzylbenzene-1,3-diamine diticarbamate and coordinating it with the metals Ni(II), Mn(II) and Cu(II). ). The three metal complexes were characterized by infrared spectroscopy, which showed the particular bands of the diticarbamate 𝑣(C-S), 𝑣(N-C) and the union of these with the metal centers (M-S). Also characterized by elemental analysis in order to suggest the molecular formula [(C22H18N2S4) -2M+2]2 in complement with the ultraviolet-visible spectra, allowing the intra-ligand, metal-ligand, and d->d transitions to be evidenced. , concluding that the copper complex possibly has a square-planar geometry, with a molecular formula [(C22H18N2S4) - 2 (M+2)3], different from the one proposed, with a copper atom joining in an Isobidentate manner to one of the groups. dithiol, and the other two Biconnectively to the second dithiol group of the ligand. It is confirmed that the nickel complex formed according to the suggested square planar formula and geometry. Meanwhile, a possible coordination of three DTC ligands with octahedral geometry was suggested for manganese.Item Síntesis y caracterización de derivados de m-fenilendiamina con los metales de transición Mn2+, Ni2+ y Cu2+ como potenciales materiales antibacterianos(Universidad Santiago de Cali, 2021) Rendón Bolaños, Stiwenn Andrés; Flórez López, Edwin (Director); Ávila Torres, Yenny Patricia (Directora)In the present research it was possible to synthesize and characterize by spectroscopy FTIR, UV-Vis thermal analysis TGA-DSC and atomic absorption, the ligand phenyl-1,3-N,N'-bisditiocarbamate of potassium, derived from m-phenyldiamine and its coordination compounds with metallic salts of Ni2+, Cu2+ and Mn2+. This spectroscopic analysis allowed to identify the bidentate coordination mode of the DTC with each of the metals and to suggest a flat square geometry for the 3 coordination compounds obtained.Item Síntesis y determinación estructural de aminoésteres derivados de benzaldehído y salicilaldehído y estudio teórico de sus compuestos de coordinación con Sb (III)(Universidad Santiago de Cali, 2021) Ágredo Bolaños, Ana Ivette; Flórez López, Edwin (Director); Ávila Torres, Yenny Patricia (Directora)A condensation reaction was carried out between benzaldehyde and salicylaldehyde with the hydrochloride of the glycine aminoester, followed by reduction with NaBH4 to obtain two α-aminoesters with yields of 81% and 91% respectively, the products were characterized by IR, 1H NMR, 13C and Mass Spectrometry. In addition to this, a theoretical analysis was carried out using the MM2 force field stability method, which allowed determining the energetic properties of the ligands and the viability of coordinating to Sb (III). Taking into account that structures with a low total energy and a high difference between EHOMO and ELUMO are characterized as stable, three structures of coordination complexes between α-aminoesters and Sb (III) are proposed.