Ciencias Exactas y Ciencias de la Salud
Permanent URI for this collectionhttps://hdl.handle.net/11285/551039
Pertenecen a esta colección Tesis y Trabajos de grado de las Maestrías correspondientes a las Escuelas de Ingeniería y Ciencias así como a Medicina y Ciencias de la Salud.
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- Modification of photosensitive resin with 0D and 2D nanoparticles towards printing scalability(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-12-05) Meza Diarte, Salvador Alejandro; Sustaita Narváez, Alan Osiris; Rodríguez Hernández, Gerardo; Segura Cárdenas, Emmanuel; Melo Máximo, Dulce Viridiana; School of Engineering and Sciences; Campus Monterrey; Iturbe Ek, JackelineComposite materials, recognized for their ability to synergize the properties of multiple constituents, have become indispensable in modern engineering and manufacturing. Polymer composites, a prominent category within this field, are particularly valued for their lightweight, cost-effective nature, and ease of processability. This study investigates the integration of composite materials with vat polymerization 3D printing, focusing on the development of advanced polymer-based nanocomposites with tailored functional properties, by modifying commercially available photosensitive resins through ultrasonic dispersion of 0D and 2D nanoparticles: silicon dioxide (SiO2) and organo-modified clay Cloisite 30B (C30B), respectively. The SiO2 nanoparticles were functionalized with alkyl silane groups CTMS and OTS to achieve hydrophobicity. Therefore, this work aims to enhance the hydrophobic and flame-resistant characteristics of 3D printed components. A practical experimental methodology for the resin modification by ultrasonic dispersion was developed. The incorporation of functionalized SiO2 achieved intrinsically hydrophobic 3D printed specimens, with contact angle of up to 133°. The incorporation of C30B increased significantly mechanical properties with respect to neat resin, obtaining an increase of 37% in Young’s modulus, 39% in elongation, and 0.95 MPa. It also increased combustion temperature by 12 °C in the formulation with 5% clay concentration. XRD and TEM results confirm a clay exfoliation was achieved after polymerization, and the mechanism was proposed. A Jacob’s cure depth working curve was developed for both modifications to determine their printing parameters as the first step towards printing scalability. UV-Vis analysis confirmed that both modifications preserved the printability of the resins, demonstrating the feasibility of fabricating high-performance nanocomposites using vat polymerization
- Determination of parameters for the synthesis of carbon nanomaterials by ultrasonic spray-chemical vapor deposition(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2022-12) Hurtado Alvarez, Agustín; SUSTAITA NARVAEZ, ALAN OSIRIS; 226812; Sustaita Narváez, Alan Osiris; puelquio/mscuervo; Ulloa Castillo, Nicolás Antonio; Lozano Sánchez, Luis Marcelo; González González, Francisco José; School of Engineering and Sciences; Campus Monterrey; Iturbe Ek, JackelineNanotechnology is a field that keeps growing every year, especially carbon nanomaterials like graphene or carbon nanotubes, which are the main ones employed in developing patents [1]. These nanomaterials exhibit outstanding properties like young modules around 1 TPa [2], experimental surface area above 1,300 m2g−1 [3], among many other thermal and conductivity properties. Although a lot of research is carried out, this is not reflected in the number of products on the market for daily use. The main boundaries that delay the adoption of these materials are cost/price, production methods scaling and material quality/consistency [4]. Chemical vapor deposition (CVD) is a methodology capable of synthesizing different carbon allotropes by varying the processing parameters [5]. Also, it is a very versatile methodology because it can use precursors in different physical states and chemical natures [6]. When the carbon precursors are in a liquid state with the catalyst dissolved, an activation mode is necessary to nebulize the solution to facilitate pyrolysis [7]. The ultrasonic spray is an activation mode that assists CVD by isolating the precursor solution through the acoustic cavitation that expands and compresses the droplets until it implodes into micron-sized droplets that facilitate the pyrolysis of the reactants [8]. In collaboration with the author of this thesis, Ceron designed and manufactured a CVD system assisted by ultrasonic spray to later automate it with routines to synthesize specific carbon nanomaterials [9]. Unlike other systems, this one includes a polytetrafluoroethylene (PTFE) membrane that separates the precursor solution from the transducer to increase the dispositive’s lifetime while allowing the user to change the nebulization chamber (useful for post-processing steps). The first trials of the system provide exciting results because they synthesize different morphologies by changing the processing parameters. However, a structured design of experiments (DOE) is needed to improve the synthesized product. For this reason, this thesis aimed to determine the conditions to synthesize a specific morphology with fewer defects and maximize mass production. To do so, 23 DOE was performed by duplicating. The independent variables were the concentration (molarity) of the catalyst in the precursor solution, the Ar flow (L/min) and the temperature. Meanwhile, the dependent variables were ID/IG rate and mass production (grams). Each experiment was characterized by Raman spectroscopy and Scanning Electron Microscopy (SEM). Raman spectra and SEM micrographs validate that the system designed can synthesize different kinds of carbon allotropes like carbon spheres or CNT. Current results suggest that the system can synthesize in a homogeneous way CNT at 800ºC. Nevertheless, future TEM characterization will allow us to validate the obtaining of MWCNT (as suggested by Raman analysis). A 23 design of experiments was done to minimize the number of defects in the synthesized carbon nanostructures, where it was found that at 800ºC, 0.15M and 1.5 L/min, the smallest value of ID/IG ratio was obtained. A similar study was performed to maximize mass production, where the highest mass is obtained at 800ºC, 0.1M and 1.0 L/min. Since the conditions of each study were different, it was looked for the parameters that balanced the two properties better, being 800ºC-0.1M-1.0L/min the conditions that maximized the mass production without affecting too much the quality of the graphene sheet because this condition was the second condition with fewer defects.
- Automatización de síntesis de nanoestructuras de carbono por el método de espray pirolisis por ultrasonido.(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2022-06) Cerón Capitaine, Johan Alain; SUSTAITA NARVAEZ, ALAN OSIRIS; 226812; Sustaita Narváez, Alan Osiris; puemcuervo; Iturbe-Ek, Jackeline; Ulloa Castillo, Nicolás Antonio; Olvera Trejo, Daniel; Escuela de Ingeniería y Ciencias; Campus Monterrey; Segura Cárdenas, EmmanuelSe diseño, desarrollo e implemento un sistema automatizado de síntesis de nanoestructura de carbono usando uno de los métodos con gran potencial para el escalamiento industrial, el método de espray pirolisis por ultrasonido. Este se apoya de un fenómeno físico, estudiado por la sonoquímica, llamado cavitación acústica. Esta es responsable de pulverizar una sustancia liquida en tamaño de micras, siendo esto útil para la síntesis dado que requiere menos energía para descomponerse las moléculas. Para poder realizar el sistema de espray pirolisis por ultrasonido fue necesario diseñar, desarrollar e implementar el reactor ultrasónico. Se nombrará reactor ultrasónico al conjunto de componentes esenciales para generar la pulverización por medio de ultrasonido. Partiendo de la cámara de pulverizo, cristalería donde se llevó a cabo la cavitación, se creó la abrazadera y el soporte de la cámara de pulverizado. Estos fueron clave para mantener segura a la cristalería. La clave para generar la cavitación es el transductor ultrasónico por lo que se hacen diferentes pruebas que garanticen el correcto funcionamiento de este. Se llego a descubrir que puede generar la cavitación de manera indirecta y con uso de una membrana de politetrafluoroetileno aislamos al transductor del contenido de la cámara. Se diseña un posicionador que se coloca dentro de un recipiente para mantener al transductor ultrasónico centrado en la membrana. Ya una vez armado este subsistema se integran a los componentes del sistema de pirolisis, dejando el método de espray pirolisis por ultrasonido para síntesis manual de nanoestructura de carbono. Automatizar procesos químicos dentro de laboratorios es crucial para potencializar éxitos tempranos. Por ello el sistema pasa a automatizarse, creando un circuito impreso, se dejó las bases de su automatización con las que podrá controlar el tiempo de síntesis, la recirculación y el control de temperatura del horno. Se finalizo el proyecto con técnicas de caracterización, microscopia electrónica de barrido y difracción de rayos X, para la validación del correcto funcionamiento del sistema, así como corroborar síntesis de alótropos de carbono.
- Polyethylene engineering for application in passive personal thermal management(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2021-11-30) Ramos Tirado, Jesús Eduardo; SUSTAITA NARVAEZ, ALAN OSIRIS; 226812; Sustaita Narváez, Alan Osiris; puemcuervo; Iturbe Ek, Jackeline; Elias Zúñiga, Alex; Mata Padilla, José Manuel; School of Engineering and Sciences; Campus Monterrey; Lozano Sánchez, Luis MarceloThermal comfort is the mind condition when we feel satisfaction with the environmental conditions. Thermoregulatory clothing is an energy-saving way to achieve thermal comfort conditions. Lately, there have been efforts to develop materials with thermoregulatory properties. The simple structure of polyethylene makes a good option for engineering thermoregulatory fibers due to its transparency windows in the mid-IR, where we emit radiation to the environment. In this project, it is proposed an alternative method to fabricate oriented UHMWPE films with high crystallinity and high fibers and molecular chains orientation to enhance the thermal conductivity of the films. The restructuring of the films was measured using FTIR/ATR Spectroscopy, DSC, XRD, SWAXS and SEM. The films obtained show an increase in crystallinity and chains orientation as the draw ratio increase, which leads to a higher thermal conductivity.
