Person:
Guzmán Solís, Eduardo

First Name

Eduardo

Last Name

Guzmán Solís

URI

https://hdl.handle.net/20.500.14352/76095

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Ciencias Químicas

Department

Química Física

Area

Química Física

Identifiers

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Now showing 1 - 10 of 21

Project number: 322
La ciencia y tecnología químicas al servicio de la sociedad: actividad formativa para los alumnos del Máster en Ciencia y Tecnología Químicas
(2023) Guzmán Solís, Eduardo; Guerrero Martínez, Andrés; Sánchez Benítez, Francisco Javier; Lobato Fernández, Álvaro; Barrio Redondo, Melissa del; Pradanas González, Fernando; Cano Rico, Israel; Castillo Martínez, Elisabet; Kayser González, Paula; Moya Cerero, Santiago de la; Gómez Gutiérrez, Julián; Palomares Gracia, Óscar; Pastor Vargas, Carlos; Encinas García, Noemí; García Martín, Gustavo; Lasanta Carrasco, María Isabel
Ensamblaje Electrostático de sistemas poliméricos cargados: fabricación y propiedades
(2015) Guzmán Solís, Eduardo; Ortega Gómez, Francisco; González Rubio, Ramón
La Tesis Doctoral presentada consta de un estudio de los procesos de fabricación de monocapas y multicapas de sistemas poliméricas cargados, así como de las propiedades de los sistemas obtenidos. El método de fabricación empleado en todos los sistema s estudiados se basa en la interacción electrostática entre cadenas poliméricas y superficies (o capa poliméricas), de ahí el nombre de ensamblaje electrostático (ESA). En el desarrollo de la Tesis se evalúan los diferentes comportamientos observad os en monocapas y multicapas (obtenidas por la adsorción alternada de monocapas de polímeros con carga opuesta) ante diferentes modificaciones tanto de la naturaleza de los polímeros empleados en la adsorción como de las condiciones de ensamblaje. Pa ra realizar el estudios completo se han empleado diversas técnicas experimentales que permiten la caracterización de estos sistemas tanto durante el proceso de fabricación (D-QCM y elipsometría) como una vez formadas las películas (AFM, XPS, reflecti vidad de neutrones y rayos X, potencial de superficie, potencial ?, ángulo de contacto). Con la batería de técnicas empleadas se ha obtenido información tanto estructural como de los procesos de formación (cinéticas de adsorción) y propiedades (propi edades mecánicas, contenido en agua, carga superficial) de los materiales obtenidos. Los sistemas estudiados presentan ciertas peculiaridades en lo referente a sus procesos de construcción y propiedades, que permiten anticipar posibles aplicaciones de los mismos en diversas áreas de la nanotecnología. Por un lado, la cinética de adsorción de las capas obtenidas para todos los casos ha mostrado un carácter bimodal, con una primera etapa relacionada con la difusión de las cadenas poliméricas hac ia la superficie, seguida de una etapa de reorganización de las cadenas preadsorbidas. Por otro lado, se han observado ciertas propiedades físico-químicas comunes en todos los sistemas, como son un alto grado de hidratación de las películas que lleva a la formación de estructuras altamente plastificadas, similares a un gel polimérico. En lo referente al estudio de las monocapas se ha analizado esencialmente el efecto de la arquitectura molecular y la naturaleza como polielectrolitos de las cadenas empleadas sobre el ensamblaje, siendo el estudio del ensamblaje de monocapas esencial para el posterior estudio realizado de la construcción de multicapas por ensamblaje capa a capa (LbL).
Aqueous dispersions of oleic acid nanodroplets for thymol encapsulation
(Colloids and Surfaces A, 2024) Paula Gutiérrez-González; Peña Fernández, Laura Luisa; Alejandro Lucia; Ortega Gómez, Francisco; González Rubio, Ramón; Guzmán Solís, Eduardo
This study focuses on the use of oleic acid to disperse thymol as nanodroplets, stabilized by a mixture of alkylpolyglucoside and lecithin, in an aqueous environment. This approach aims to develop innovative platforms for the encapsulation and release of poorly water-soluble molecules such as thymol, useful for drug delivery and insecticide systems. The results highlight the critical role of controlling the content and concentration of the oil phase (thymol-oleic acid mixture) in achieving optimal thymol dispersion and nanodispersion stability. The interplay between the ability of oleic acid to inhibit thymol crystallization and the maximum dispersible oil amount is crucial. It affects the dispersion of thymol within the nanodroplets and influences coalescence and Ostwald ripening phenomena. The balance between oleic acid and thymol content is key: while oleic acid stabilizes dispersions, higher thymol content increases droplet size, potentially triggering destabilization. The uneven distribution of thymol within the droplets, revealed by fluorescence spectroscopy, suggests that up to three different chemical environments exist. This investigation may pave the way for the development of efficient platforms to improve access to biologically relevant, poorly soluble molecules.
Project number: 192
Digitalización del laboratorio de Química Física I en tiempos de COVID-19
(2021) Guerrero Martínez, Andrés; Díaz Blanco, Cristina; Sánchez Benítez, Francisco Javier; Caselli, Niccolo; Aoiz Moleres, Francisco Javier; Fernández Castillo, Jesús; González MacDowel, Luis; Guzmán Solís, Eduardo; Menéndez Carbajosa, Alicia Marta; Suardíaz del Río, Reynier; Verdasco Costales, Juan Enrique; Marggi Poullain, Sonia
Physico-chemical challenges on the self-assembly of natural and bio-based ingredients on hair surfaces: towards sustainable haircare formulations
(Green Chemistry, 2023) Luengo, Gustavo S.; Leonforte, Fabien; Greaves, Andrew; González Rubio, Ramón; Guzmán Solís, Eduardo
Polymers and surfactants are used in many technological and industrial applications such as the manufacture of functional materials and coatings, personal care and pharmaceutical products, food science, paints, anti-icing fluids, tertiary oil recovery and the paper industry. Polymer–surfactant mixtures are particularly important in shampoos and conditioners. However, as in almost every other industry over the past five or more decades, the performance of hair care formulations has been significantly improved by the use of petrochemical-derived ingredients. As a result, cosmetic formulations, and hair care formulations in particular, have been based primarily on polymers and surfactants that are neither renewable, nor derived from environmentally friendly processes, nor have a positive environmental impact. This contrasts with the extensive use of natural and renewable products, mainly plant extracts, in cosmetics in ancient times. Therefore, the substitution of currently used ingredients with others of natural origin has been a top priority for the cosmetic industry over the last two decades, and in order to achieve greater consumer acceptance, it is crucial to maintain and, where possible, improve the technical performance of such products. This paper describes the complexities and challenges of developing greener shampoo and conditioner ingredients and formulations to meet current and future needs, and outlines a methodological approach based on model hair surfaces and a selection of appropriate experimental and numerical techniques to achieve our goals. Some encouraging technical routes using biosurfactants, biopolymers and bio-based polymers are presented, along with the significant opportunity to obtain a wide range of green ingredients through molecular design and well-controlled biotechnological processes. Similar concerns apply to other cosmetic products such as waxes, fragrances, bleaching agents, etc.
Ionic strength effect in the equilibrium and rheological behavior of an amphiphilic triblock copolymer at the air/solution interface
(Colloids and Interface, 2024) Carbone, Carlo; Guzmán Solís, Eduardo; Maldonado-Valderrama, Julia; González Rubio, Ramón; Ortega Gómez, Francisco
This study investigates the effect of an inert salt (NaCl) on the equilibrium interfacial tension and dilatational modulus of Pluronic F-68 copolymer, a triblock copolymer consisting of two terminal blocks of poly(ethylene oxide) and a less hydrophilic central block of poly(propylene oxide). Interfacial tension measurements were carried out using a surface force balance and a drop shape tensiometer, while rheological measurements were carried out in two different frequency ranges. This involved the use of the oscillatory barrier/droplet method and electrocapillary wave measurements, complemented by an appropriate theoretical framework. This work aimed to elucidate the influence of NaCl on the interfacial behavior of Gibbs monolayers of Pluronic F-68. In addition, this study highlights some of the technical and theoretical limitations associated with obtaining reliable dilatational rheological data at high frequencies (<1 kHz) using electrocapillary wave measurements. The results provide valuable insights into the interplay between salt presence and interfacial properties of Pluronic F-68 and highlight the challenges of obtaining accurate dilatational rheological data under specific measurement conditions.
Fluid interfaces as models for the study of lipid-based films with biophysical relevance
(Coatings, 2023) Argudo, Pablo G.; Maestro, Armando; Guzmán Solís, Eduardo
This comprehensive review aims to provide a deep insight into the fascinating field of biophysics in living organisms through the study of model fluid interfaces that mimic specific lipid-based structures with biophysical relevance. By delving into the study of these physiological fluid interfaces, we can unravel crucial aspects of their behavior, lateral organization, and functions. Through specific examples, we will uncover the intricate dynamics at play and shed light on potential pathogenic conditions that may result from alterations in these interfaces. A deeper understanding of these aspects can lead to the emergence of novel technologies and medical advances, potentially leading to the development of innovative treatments and diagnostic tools.
Non-equilibrium states in polyelectrolyte-surfactant systems at fluid interfaces: A critical review
(Current Opinion in Colloid and Interface Science, 2024) Ana Puente-Santamaría; Ortega Gómez, Francisco; Armando Maestro; González Rubio, Ramón; Guzmán Solís, Eduardo
Over the last two decades, a significant body of research has been developed trying to understand the association and properties of mixtures formed by oppositely charged polyelectrolytes and surfactants. Particular emphasis has been given to their interfacial properties and the intriguing formation of nonequilibrium states. The synergy between these components at interfaces has attracted considerable attention due to its relevance in various industrial and biological applications. The combination of oppositely charged entities leads to complex interactions that influence the stability and behavior of interfaces. This review critically examines recent advances toward understanding the interfacial behavior when polyelectrolytes and surfactants coexist. Emphasis is placed on the existence of nonequilibrium states, shedding light on transient phenomena and kinetic aspects that play a crucial role in the overall system behavior. This will provide insights into the mechanisms governing the interfacial phenomena in these mixed systems. In summary, this review will contribute to the fundamental understanding of colloidal and interfacial science, offering a valuable perspective on designing and optimizing materials with tailored properties.
Exploring the world of rhamnolipids: A critical review of their production, interfacial properties, and potential application
(Current Opinion in Colloid and Interface Science, 2024) Guzmán Solís, Eduardo; Ortega Gómez, Francisco; González Rubio, Ramón
Rhamnolipids are very promising sugar-based biosurfactants, generally produced by bacteria, with a wide range of properties that can be exploited at an industrial and technological level, e.g. in cosmetics, food science, or oil recovery, to provide benefits for human health and the environment. This has led to intensive research into optimizing their production to increase yields and minimize costs, which is challenging because biotechnological methods for rhamnolipid production result in complex product mixtures and require the introduction of complex separation strategies to ensure the purity of the rhamnolipid obtained. This is an important issue for the introduction of rhamnolipids to the market due to the differences that exist between the properties of the different congeners. This review attempts to provide an overview of the interfacial properties, potential applications, and recent advances in understanding the molecular mechanisms that govern the adsorption to interfaces and assembly in solution of rhamnolipids. In addition, the review also discusses some general aspects related to the production and purification methods of rhamnolipids, highlighting the need for further research to fully exploit their potential. It is hoped that this review will contribute to the growing body of knowledge about rhamnolipids and stimulate further research in this field.
Study of the Liquid/Vapor Interfacial Properties of Concentrated Polyelectrolyte–Surfactant Mixtures Using Surface Tensiometry and Neutron Reflectometry: Equilibrium, Adsorption Kinetics, and Dilational Rheology
(2018) Llamas, Sara; Guzmán Solís, Eduardo; Akanno, Andrew; Fernández-Peña, Laura; Ortega Gómez, Francisco; Campbell, Richard; Miller, Reinhard; González Rubio, Ramón