Browsing by Author "Silva, Nataly"
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Publication Advances in the Sustainable Development of Biobased Materials Using Plant and Animal Waste as Raw Materials: A Review(2024) Salazar Sandoval, Sebastián Andrés; Amenábar, Alejandra; Toledo, Ignacio; Silva, Nataly; Contreras, PaulinaThere is substantial concern about critical environmental problems related to waste in production sectors such as textile, construction, and packaging. The materials ascribed to the sector’s unsustainability are primarily fabrics, plastic, and hazardous solvents, making developing new biobased materials imperative. As such, various strategies have been investigated to convert and recycle waste and give them commercial value via the manufacture of biobased materials. This review discusses the various types of raw materials as sources to develop new biobased materials that could promote the transition toward sustainability. According to the literature, the functional qualities of biobased materials are comparable to those of synthetic materials. Raw material sources such as biomass, derived from plant and animal-based waste, are attractive due to their low cost, abundance, and biodegradability. The manufacture of biomaterials, as well as their characterization and performance, are also discussed. Further, this review will offer a comprehensive view of the potential applicability and current commercial applications of the developed biobased materials in relevant areas such as packaging, construction, textile, and wastewater remediation. This could be a potential field of research to address the environmental challenges posed by the continuous growth of the global population.Publication Controlled Release of the Anticancer Drug Cyclophosphamide from a Superparamagnetic β‑Cyclodextrin Nanosponge by Local Hyperthermia Generated by an Alternating Magnetic Field(2024) Salazar Sandoval, Sebastián Andrés; Díaz-Saldívar, Patricia; Araya, Ingrid; Celis, Freddy; Cortés-Arriagada, Diego; Riveros, Ana; Rojas-Romo, Carlos; Jullian, Carolina; Silva, Nataly; Yutronic, Nicolás; Kogan, Marcelo J.; Jara, Paulβ-cyclodextrin (β-CD) nanosponge (NS) was synthesized using diphenyl carbonate (DPC) as a cross-linker to encapsulate the antitumor drug cyclophosphamide (CYC), thus obtaining the NSs-CYC system. The formulation was then associated with magnetite nanoparticles (MNPs) to develop the MNPs-NSs-CYC ternary system. The formulations mentioned above were characterized to confirm the deposition of the MNPs onto the organic matrix and that the superparamagnetic nature of the MNPs was preserved upon association. The association of the MNPs with the NSs-drug complex was confirmed through field emission scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, dynamic light scattering, ζ-potential, atomic absorption spectroscopy, X-ray powder diffraction, selected area electron diffraction, and vibrating-sample magnetometer. The superparamagnetic properties of the ternary system allowed the release of CYC by utilizing magnetic hyperthermia upon the exposure of an alternating magnetic field (AMF). The drug release experiments were carried out at different frequencies and intensities of the magnetic field, complying with the “Atkinson−Brezovich criterion”. The assays in AMF showed the feasibility of release by controlling hyperthermia of the drug, finding that the most efficient conditions were F = 280 kHz, H = 15 mT, and a concentration of MNPs of 5 mg/mL. CYC release was temperature-dependent, facilitated by local heat generation through magnetic hyperthermia. This phenomenon was confirmed by DFT calculations. Furthermore, the ternary systems outperformed the formulations without MNPs regarding the amount of released drug. The MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assays demonstrated that including CYC within the magnetic NS cavities reduced the effects on mitochondrial activity compared to those observed with the free drug. Finally, the magnetic hyperthermia assays showed that the tertiary system allows the generation of apoptosis in HeLa cells, demonstrating that the MNPs embedded maintain their properties to generate hyperthermia. These results suggest that using NSs associated with MNPs could be a potential tool for a controlled drug delivery in tumor therapy since the materials are efficient and potentially nontoxic.Publication Copper-Modified Cellulose Paper: A Comparative Study of How Antimicrobial Activity Is Affected by Particle Size and Testing Standards(2025) Ramírez, Sara; Zúñiga, Fabián; Amenábar, Alejandra; Contreras, Paulina; Benavides, Viviana; Norambuena, Javiera; Martínez, Jessica; Silva, NatalyThis study aims to provide evidence that when testing cellulose paper modified with copper particles (CuPs), the particle size and the analysis method influence the antimicrobial activity observed by this material. Commercial CuPs of nanometric size (2.7 nm, CuNPs) and micrometric size (2.5 μm, CuMPs) were used to modify cellulose paper sheets. CuPs were incorporated during the pulp disintegration phase (stage 1) of the sheet formation process, according to the ISO 5269-1:2005 standard. Modified paper sheets retained 16% and 14% of CuNPs and CuMPs, respectively. Additionally, CuPs were distributed randomly on the fiber surfaces, often forming aggregates. Finally, the antimicrobial activity of the modified paper sheets was evaluated using ISO 20645:2004 and ISO 20743:2013. The results showed that the antimicrobial activity assessed using each standard method is conditioned by the mechanism of action of the CuPs and, therefore, by their size. It was concluded that ISO 20645:2004 is suitable for evaluating the antibacterial effect of paper/CuNPs, as nanoparticles diffuse from the paper and are released into the culture medium. In contrast, ISO 20743:2013 can be used for both CuNP- and CuMP-based paper, as it evaluates the antibacterial effect based on the direct interaction between the copper particle and the bacteriaItem Correlation between the concentration and morphology of copper microparticles and their biocidal effect on paper sheets(2020-03) Contreras, Paulina; Amenábar, Alejandra; Apablaza, V.; Martínez, J.; Lavín, R.; Silva, NatalyIn this study, different methods for incorporating mixed or laminar copper microparticles (CuMPs) during papermaking were evaluated to determine the optimum paper-making process and correlate particle concentration and shape with antimicrobial activity. The addition of CuMPs during the disintegration of dry pulp stage was observed to produce a paper with uniformly distributed CuMPs, as determined through optical microscopy and UV–Vis spectroscopy analyses by measuring absorbance spectra in different areas of papers. Determination of two indices related to the concentration and distribution of copper will allow to predict the copper content in other papers. CuMP-paper samples were evaluated for structural, optical, and mechanical strength properties according to paper industry standards. Quantitative analyses by atomic absorption showed that between 24 and 39% of CuMPs were embedded in the paper fibre, independent of particle type. Finally, antibacterial activity analyses were performed according to ISO 20645 and ISO 20743. The results showed that papers with 0.30 g of incorporated CuMPs have antimicrobial activity, independent of particle morphology, with effects observed towards Gram (+) and Gram (−) bacteria and fungus. Furthermore, the evaluation of antimicrobial activity at different times of exposure to the microorganisms showed differences in effects that were dependent on the shape of the CuMPs incorporated into paper, where laminar particles exerted a sufficient effect, while no or a slight effect was observed for mixed CuMPs against Aspergillus niger.Item Cu-paper: investigación, diseño y ciencia para la transformación de recursos locales en innovación global / Cu-paper: Research, Design, and Science to Transform Local Resources into Global Innovation(Universidad del Desarrollo. Facultad de Diseño, 2025) Amenábar, Alejandra; Contreras, Paulina; Silva, NatalyThe materials research team of the school of design at Universidad del Desarrollo (Diseño UDD) presents the cu paper project, an antimicrobial paper based on two key natural resources of the country: copper and cellulose. This research began in 2013 and involved several key components: laboratory proofs of concept, the generation of copper microparticles, and their application in industrial processes in collaboration with forestal y papelera Concepción s.a. (fpc). Additionally, the study has validated these microparticles’ antibacterial, antifungal, and antiviral effectiveness against sars-cov-2. It thus becomes a technology that limits fomite transmission, expanding the properties of paper and offering the possibility of being applied in areas where paper is the main component. It opens possible future applications in construction, health, packaging, filters, sensors, and fashion. in addition, the project was integrated into the academic training of design students through workshops to develop innovative applications of antimicrobial paper, including the exhibition at the salone satellite in Milan in 2023. This research led to the university's first national and international patent, demonstrating Chile and UDD's commitment to advancing material development.Item Diseño de un panel modular desarrollado con bioplásticos de cáscaras de naranjas para la aislación acústica y térmica del área de andenes de la "Estación intermodal La Cisterna"(Universidad del Desarrollo. Facultad de Diseño, 2024) Lara Yáñez, Manuel Andrés; Silva, NatalyEl mundo cada día incrementa el uso de energías no renovables, aumentando los niveles de contaminación y produciendo un exceso sobre los recursos que tenemos. El presente proyecto propone diseñar un material con propiedades acústicas y térmicas a partir de la cáscara de naranja y aglutinantes derivados de polímeros naturales. La investigación se desarrolla en tres etapas, la primera aborda temáticas como la sostenibilidad, ODS, fruto cítrico, características de la industria frutícola nacional y por último, los escenarios futuros hacia el desarrollo de nuevos materiales compuestos sostenibles. La segunda etapa agrupa el procedimiento por el cual se desarrollo la investigación, integrando fases de experimentación con la materia prima, caracterización del material a través de pruebas normadas y validadas mediante ensayos aplicados. La última parte explica los resultados obtenidos en la investigación, evaluando los hitos y decisiones en cada una de las etapas mencionadas anteriormente para dar paso a la conclusión y diseño a concretar del nuevo material acústico y térmico desarrollado.Publication Enhanced hydrogen generation through electrodeposited non-precious metal Zn/Cu-BTC metal-organic frameworks on indium tin oxide(2025) Castro-Castillo. Carmen; Espinoza-González, Rodrigo; Jofré-Ulloa, Pedro P,; Luis-Sunga, Maximina; Silva, Nataly; Suazo-Hernández, Jonathan; Soler, Mónica; Isaacs, Mauricio; García, GonzaloThe production of high-purity hydrogen for primary energy generation is a key goal in the renewable energy consumption model. Currently, hydrogen production through electrolysis remains quite expensive, making the development of new non-noble metal catalysts for the cathodes of acidic electrolyzers a promising strategy to lower the costs associated with this technology. In this work, Cu, Zn and Zn/Cu particles in the absence and the presence of 1,3,5-benzenetricarboxylic acid (BTC) have been synthesized via binder-free electrodeposition onto an indium tin oxide (ITO) surface as electrocatalysts to improve the hydrogen evolution reaction (HER) in acidic media. Main results highlight the fundamental role of the metal-organic framework (i.e., BTC), combined with the synergistic effect of both metal elements (i.e., Zn and Cu), in creating a uniform deposition of small crystalline particles on the ITO surface. Consequently, a low-cost and robust electrocatalyst (Zn/Cu-BTC/ITO) with enhanced catalytic performance toward the HER was synthesized. Finally, this work emphasizes how electrochemically modified surfaces, created using low-cost metals and straightforward sustainable synthesis methods, can generate atomically dispersed active sites that enhance both electrocatalytic activity and stability. This approach could contribute to the development of innovative electrodes, improving performance while reducing the cost of electrolyzers.Item Enhancing the electrocatalytic activity of Fe phthalocyanines for the oxygen reduction reaction by the presence of axial ligands: Pyridine-functionalized single-walled carbon nanotubes(2021) Oyarzún, María Paz; Silva, Nataly; Cortés-Arriagada, Diego; Silva, Juan Francisco; Ponce, Ingrid; Flores, Marcos; Tammeveski, Kaido; Bélanger, Daniel; Zitolo, Andrea; Jaouen, Frédéric; Zagal, José H.We have examined the electrocatalytic activity of iron phthalocyanine (FePc) and perchlorinated iron phthalocyanine 16(Cl)FePc for the oxygen reduction reaction (ORR) in alkaline medium with the two molecules either adsorbed on the external surface of single-wall carbon nanotubes (SWCNT) or covalently anchored via an axial pyridine ligand on pyridine-functionalized single-wall carbon nanotubes (py-SWCNT). Regardless of the particular phthalocyanine type, the ORR activity is higher when the substrate is py-SWCNT rather than SWCNT. The Tafel slopes for ORR are very similar for the two Fe macrocyclic complexes attached to SWCNTs in the two different configurations, suggesting a common rate-determining step for the ORR for all four catalysts. It is also observed that, for both the SWCNT and py-SWCNT supports, the ORR activity is higher for 16(Cl)FePc than for FePc. This is attributed to the electron-withdrawing effect of the peripheral and non-peripheral chlorine atoms in the macrocyclic ligand. While FeN4 macrocycles are known to be located on the strong binding side of a volcano correlation including several MN4 species, the chlorine substituents decrease the binding energy of O2 on the central Fe cation, thereby moving up the macrocycle catalyst towards the apex of the volcano correlation. Both the carbon surface and macrocyclic ligand effects were optimized with 16(Cl)FePc attached to py-SWCNT, which is more active than both FePc on SWCNT and FePc on py-SWCNT. Here we show that both the axial ligand and the electron withdrawing groups (-Cl) have a combined collaborative effect in increasing the catalytic activity for ORR of Fe-phthalocyanines confined on the external walls of single-wall carbon nanotubes.Publication Fast and easy synthesis of silver, copper, and bimetallic nanoparticles on cellulose paper assisted by ultrasound(2023) Araya-Hermosilla, Rodrigo; Martínez Arenas, Jessica Isabel; Zúñiga Loyola, César; Ramírez, Sara; Salazar, Sebastián; Henry, Charles S.; Lavín, Roberto; Silva, NatalyThis work focuses on a systematic method to produce Ag, Cu, and Ag/Cu metallic nanoparticles (MNPs) in situ assisted with ultrasound on cellulose paper. By tuning the concentration of AgNO3 and CuSO4 salt precursors and ultrasound time, combined with a fixed concentration of ascorbic acid (AA) as a reducing agent, it was possible to control the size, morphology, and polydispersity of the resulting MNPs on cellulose papers. Notably, high yield and low polydispersity of MNPs and bimetallic nanoparticles are achieved by increasing the sonication time on paper samples pre-treated with salt precursors before reduction with AA. Moreover, mechanical analysis on paper samples presenting well-dispersed and distributed MNPs showed slightly decreasing values of Young's modulus compared to neat papers. The strain at break is substantially improved in papers containing solely Ag or Cu MNPs. The latter suggests that the elastic/plastic transition and deformation of papers are tuned by cellulose and MNPs interfacial interaction, as indicated by mechanical analysis. The proposed method provides insights into each factor affecting the sonochemistry in situ synthesis of MNPs on cellulose papers. In addition, it offers a straightforward alternative to scale up the production of MNPs on paper, ensuring an eco-friendly method.Item Mapping experimental and theoretical reactivity descriptors of fe macrocyclic complexes deposited on graphite or on multi walled carbon nanotubes for the oxidation of thiols: Thioglycolic acid oxidation(2021) Matute, Ricardo A.; Toro-Labbé, Alejandro; Oyarzún, María Paz; Ramírez, Sara; Ortega, Daniela; Oyarce, Karina; Silva, Nataly; Zagal, José H.We have studied the electro-oxidation of thioglycolic acid (TGA) catalyzed by iron phthalocyanines and iron porphyrins (FeN4 complexes) deposited on ordinary pyrolytic graphite and on multiwalled carbon nanotubes. The purpose of this work is to establish both experimental and theoretical reactivity descriptors of MN4 macrocyclic complexes for electrooxidation of thioglycolic acid (TGA) as an extension of previous studies involving other reactions using these types of catalysts. Essentially, the reactivity descriptors are all related to the ability of the metal center in the MN4 moiety to coordinate an extra planar ligand that corresponds to the reacting molecule. This coordinating ability, represented by the M-TGA binding energy can be modulated by tuning the electron-donation ability of the ligand and it is linearly correlated with the Fe(III)/(II) redox potential of the complex. Experimental plots of activity as (log j)E at constant potential versus the Fe(III)/(II) redox potential of the MN4 catalysts give volcano correlations. A semi-theoretical plot of catalytic activities (log j)E vs DFT calculated Fe-TGA binding energies (EbTGA) is consistent with the experimental volcano-type correlations describing both strong and weak binding linear correlations of those volcanos. On the other hand, the Hirshfeld population analysis shows a positive charge on the Fe center of the FeN4 complexes, indicating that electron transfer occurs from the TGA to the Fe center in the FeN4 complexes that act as electron acceptors. The donor (TGA)-acceptor (Fe) intermolecular hardness ΔηDA was also used as reactivity descriptor and the reactivity of the Fe centers as (log j)E increase linearly as ΔηDA increases. If activity is considered per active site, the trends is exactly the opposite, i.e. a plot of (logTOF)E increases linearly as ΔηDA decreases as expected form the Maximum Hardness-Principle. A plot of (logTOF)E versus E°’Fe(III)/(II) gives a linear correlation indicating that the activity per active site increases as the redox potential decreases.Item Modulation of the electrocatalytic activity of Fe phthalocyanine to carbon nanotubes: electrochemistry of l-cysteine and l-cystine(2019) Silva, Nataly; Castro-Castillo, Carmen; Oyarzún, María Paz; Ramírez, S.; Gutierrez-Ceron, C.; Marco, J.F.; Silva, Juan Francisco; Zagal, José H.We have evaluated the electrocatalytic activity of hybrid electrodes containing Fe(II) phthalocyanine and tested these electrodes for l-cysteine oxidation and l-cystine reduction. The hybrid electrodes consisted of pristine multi-walled carbon nanotubes and functionalized with –COOH, –NH2 groups (MWCNT-p, MWCNT-c and MWCNT-a). These MWCNTs were modified with iron (II) phthalocyanine (FePc). The characterization of the hybrid systems was performed using X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and AFM with the purpose of elucidating the type of interaction between FePc and MWCNTs. The Fe(II)/(I) and Fe(III)/(II) redox potentials associated with the metal center where evaluated using cycling voltammetry. The redox processes are slightly affected by the presence of MWCNTs. The activity for both reactions increases substantially by the presence of modified MWCNTs essentially by an area effect. However, when the currents are normalized by the amount of active sites estimated from the surface coverages of FePc, the activities are still higher for FePc attached to MWCNTs. The data for l-cysteine oxidation fits well on a volcano correlation published previously for several metal phthalocyanines and metalporphyrins.Publication Nanomaterials Based on Honey and Propolis for Wound Healing—A Mini-Review(2022) Jaldin, Limberg; Silva, Nataly; Martínez, JessicaWound healing is a public health concern worldwide, particularly in chronic wounds due to delayed healing and susceptibility to bacterial infection. Nanomaterials are widely used in wound healing treatments due to their unique properties associated with their size and very large surface-area-to-volume ratio compared to the same material in bulk. The properties of nanomaterials can be expanded and improved upon with the addition of honey and propolis, due to the presence of bioactive molecules such as polyphenols, flavonoids, peptides, and enzymes. These bionanomaterials can act at different stages of wound healing and through different mechanisms, including anti-inflammatory, antimicrobial, antioxidant, collagen synthesis stimulation, cell proliferation, and angiogenic effects. Biomaterials, at the nanoscale, show new alternatives for wound therapy, allowing for targeted and continuous delivery of beekeeping products at the injection site, thus avoiding possible systemic adverse effects. Here, we summarize the most recent therapies for wound healing based on bionanomaterials assisted by honey and propolis, with a focus on in vitro and in vivo studies. We highlight the type, composition (honey, propolis, and polymeric scaffolds), biological, physicochemical/mechanical properties, potential applications and patents related of the last eight years. Furthermore, we discuss the challenges, advantages, disadvantages and stability of different bionanomaterials related to their clinical translation and insight into the investigation and development of new treatments for wound healing.Item Oxide copper nanoparticles stabilized by acrylonitrile and methyl methacrylate polar monomers through a ligand exchange reaction(2021) Rodríguez, Bárbara; Ramírez, Sara; Gutiérrez, Pablo; Silva, Nataly; Díaz-Aburto, Isaac; García, Andreina; Martínez, IvánThis research reports the synthesis of copper oxide nanoparticles (CuONP) functionalized by the polar monomers acrylonitrile (ACN) and methyl methacrylate (MMA). The synthesis was achieved by a practical exchange ligand reaction from CuONP previously stabilized by hexadecyltrimethylammonium bromide (CTAB). The replacement of CTAB by ACN or MMA produced the functionalized nanoparticles CuONP-ACN and CuONP-MMA, respectively. The functionalized nanoparticles were characterized by ultraviolet-visible spectroscopy (UV–vis), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (SEM), dynamic light scattering (DLS), Zeta potential, x-ray diffraction (XRD), high-resolution-transmission electron microscopy (HR-TEM), and selected area electron diffraction (SAED) analysis. Changes in surface plasmon resonance (SPR) band and the functional group bands observed in UV–vis and FTIR spectra confirmed the efficient replacement of CTAB by polar monomers. Moreover, CuONP-ACN and CuONP-MMA showed a negative surface charge with spherical morphology. X-ray diffraction (XRD) analysis showed that a monoclinic CuO crystal system was formedPublication Production of Graphite Nanoplatelets via Functionalized Polyketone-Assisted Diels–Alder Chemistry: Evidence of Reduced Layer Thickness and Enhanced Exfoliation Efficiency(Polymers, 2025) Cisternas, Ricardo; Orellana, Jaime; Silva, Nataly; Correa-Puerta, Jonathan; Pucci, Andrea; Bose, Ranjita K.; Picchioni, Francesco; Araya-Hermosilla, Esteban; Araya-Hermosilla, RodrigoThis study introduces an efficient and scalable method for the top-down exfoliation of graphite into graphite nanoplatelets (GNPs) using polyketones (PKs) functionalized with Diels–Alder (DA) active groups. Leveraging the reversible covalent interactions facilitated by furan and thiophene moieties in PK, combined with melt-mixing and shear force, this process achieves significant exfoliation while preserving the structural integrity of the resulting material. Thermal and rheological analyses demonstrate enhanced interfacial adhesion and stability within polymer composites attributed to the DA-driven interactions between functionalized PK and graphite. Comparative evaluations demonstrate that furan-functionalized PK exhibits superior exfoliation efficiency, highlighting its potential for producing high-quality exfoliated graphite suitable for advanced nanocomposite applications that require enhanced thermal, mechanical, and electrical properties. This method seamlessly integrates sustainability with industrial scalability, offering significant advancements in developing GNP-based materialsItem Review on Generation and Characterization of Copper Particles and Copper Composites Prepared by Mechanical Milling on a Lab-Scale(2023) Salazar Sandoval, Sebastián; Silva, NatalyThis review aims to expose mechanical milling as an alternative method for generating copper-based particles (copper particles (CuP) and copper composites (CuC)); more specifically, via a top-down or bottom-up approach, on a lab-scale. This work will also highlight the different parameters that can affect the size distribution, the type, and the morphology of the obtained CuP or CuC, such as the type of mechanical mill, ball-to-powder ratios (BPR), the milling speed, milling time, and the milling environment, among others. This review analyzes various papers based on the Cu-based particle generation route, which begins with a pretreatment step, then mechanical milling, its approach (top-down or bottom-up), and the post-treatment. Finally, the characterization methods of the resulting CuP and CuC through mechanical milling are also discussed.Publication Synthesis and characterization of magnetite/gold core shell nanoparticles stabilized with a -cyclodextrin nanosponge to develop a magneto-plasmonic system(2023) Salazar Sandoval, Sebastián; Santibáñez, Daniel; Riveros, Ana; Araneda, Fabián; Bruna, Tamara; Silva, Nataly; Yutronic, Nicolás; Kogan, Marcelo J.; Jara, PaulMagnetite/gold core-shell nanoparticles (magnetite/gold NPs) have important optical and magnetic properties that provide potential for applications, especially biomedical ones. However, their preparation is not exempt from difficulties that might lead to unexpected or undesired structures. This work reports the synthesis and characterization of magnetite/gold NPs using tetramethylammonium hydroxide (TMAH) to promote the formation of a continuous interface between the magnetite core and the thin gold shell. The synthesized magnetite/gold NPs were characterized using transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), field emission scanning electron microscope (FE-SEM), ζ-potential, vibrating sample magnetometer (VSM), selected area electron diffraction (SAED), UV-Visible spectroscopy, and dynamic light scattering (DLS), confirming the core-shell structure of the NPs with narrow size distribution while evidencing its plasmonic and superparamagnetic properties as well. Further, the magnetite/gold NPs were associated and stabilized with a β-cyclodextrin nanosponge (β-CDNSs), obtaining a versatile magneto-plasmonic system for potential applications in the encapsulation and controlled release of drugs.Item Testing Reactivity Descriptors for the Electrocatalytic Activity of OPG Hybrid Electrodes Modified with Iron Macrocyclic Complexes and MWCNTs for the Oxidation of Reduced Glutathione in Basic Medium(Springer Nature, 2019) Gutiérrez-Cerón, Cristián; Silva, Nataly; Ponce, Ingrid; Zagal, José H.In this work we have tested the Fe(III)/(II) redox potential of the catalysts as a reactivity descriptors of iron macrocyclic complexes (FeN4) adsorbed on multi-walled carbon nanotubes (MWCNTs) and deposited on ordinary pyrolytic graphite (OPG). The reaction examined is the oxidation of glutathione (GSH) a biologically important molecule. The experiments were conducted in 0.1 M NaOH and kinetic measurements were performed on MWCNT previously modified with FeN4 macrocycle complexes. This modified FeN4–MWCNTs were deposited on pristine OPG electrodes. From previous work it is known that for FeN4 complexes directly adsorbed on OPG, the activity as (log i)E plotted versus the Fe(II)/(I) redox potential follows a volcano correlation for the oxidation of glutathione. We wanted to test these correlations on hybrid electrodes containing MWCNTs and essentially the carbon nanotubes have no influence in these correlations and the redox potentials a are good reactivity descriptors, regardless of the way the FeN4 catalysts are attached to the electrode. Further, we find volcano correlations when using the Fe(II)/(I) and the Fe(III)/(II) redox potentials as reactivity descriptors. The volcano correlation when using the Fe(III)/(II) redox potential exhibits a maximum at E° = –0.26 V vs SCE which is close to the potential for comparing the different activities. This interesting result seems to indicate that the maximum cannot be explained only in terms of the Sabatier principle where θRS, the surface coverage of adsorbed intermediate is close to 0.5 but instead to a surface coverage of active sites θFe(II) equal to 0.5, which occurs at the Fe(III)/(II) formal potential.Item Tocot post proceso: impresión 3d y el incremento en la usabilidad de materiales de bajo costo dentro del proceso de prototipado rápido.(Universidad del Desarrollo. Facultad de Diseño, 2022) Anselmo Iduya, Nicolás; Reyes, Mauricio; Silva, NatalyLa impresión en 3D es una de las herramientas más utilizadas para crear prototipos dentro del entorno de diseño, industrial y maker debido principalmente a sus atributos de velocidad y precisión. Cabe considerar, que las propiedades del prototipo impreso dependen del tipo de material que se utiliza en su fabricación, siendo ácido poliláctico (PLA) el filamento más utilizado por su precisión dimensional, facilidad de uso, además de su bajo costo ($8.200 x kg). Sin embargo, debido a sus características, cuenta con un bajo alcance y resolución a la hora de ser utilizado en el proceso de prototipado y validación. En esta investigación se aborda la siguiente pregunta: ¿Cómo la aplicación de revestimientos nos permitirá mejorar la utilidad del PLA en el prototipado? Esto con el fin de otorgarle al usuario las herramientas necesarias para prototipar con mayor versatilidad de propiedades requeridas, manteniendo el bajo costo del prototipado rápido, y los aspectos de forma y dimensiones de su proyecto. Dotando a quién necesite prototipar con la capacidad de hacerlo de la mejor forma posible.Item Transparenta(Universidad del Desarrollo. Facultad de Diseño, 2022) Carrasco Zapata, Isidora; Reyes , Mauricio; Silva, NatalyEn Chile existe un vacío de información sobre las medidas y campañas de acoso sexual callejero. Del 93,8% de las mujeres que han sufrido acoso sexual en el transporte público y privado, un 60% de las personas que denuncian no tienen toda la información para hacerlo. Estos hechos indican que faltan mecanismos para informar eficazmente a las usuarias y a las víctimas sobre el proceso y las medidas. Esta problemática esta por el hecho en como se implementan las campañas informativas, estas se dirigen a un entorno por igual y no se orientan a la educación. Entonces, ¿Cómo podría el diseño de experiencia a través de la gamificación contribuir a educar y concientizar el Acoso sexual callejero? Este proyecto tiene como objetivo diseñar una plataforma basada en experiencia de usuario y gamificación para educar y concientizar el acoso sexual callejero. Esto a partir de la creación de una plataforma interactiva para el usuario, creando una simulación en el que pueda educarse y dialogar sobre las medidas del acoso sexual callejero.Publication Upcycling Salmon Skin Waste: Sustainable Bio-Sequins and Guanine Crystals for Eco-Friendly Textile Accessories(2024) Clavel, Valentina; Salazar Sandoval, Sebastián Andrés; Silva, Nataly; Araya-Hermosilla, Rodrigo; Amenábar, Alejandra; Contreras, PaulinaThe significant environmental impact from fashion and textile industries has spurred interest in sustainable alternatives, especially for accessories like sequins and beads, whose usage has surged post-pandemic. This study explores the potential of utilizing salmon industry waste from Chile to produce bio-sequins (BS) and guanine crystals (GC) from salmon skin. The production of BS offers a strategy to reduce reliance on non-renewable resources and support sustainable waste management, as these materials decompose naturally without harmful residues. Physicochemical and mechanical characterization of the BS by using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), thermogravimetric analysis (TGA), X-ray powder diffraction (XRPD), and Fourier transform infrared spectroscopy (FT-IR), evaluated their feasibility for textile, design, and fashion applications. Additionally, GC were extracted from salmon scales using less hazardous solvents such as acetone, ethanol, and acetic acid, and subsequently immobilized on the BS for decorative purposes. Notably, tensile mechanical properties of the BS improved up to 75% after guanine decoration and exposure to simulated environmental factors like UV radiation. This work addresses the dual challenge of pollution and resource depletion, demonstrating that BS from salmon skin offer an eco-friendly alternative. It underscores the importance of adopting sustainable practices throughout the fashion industry’s production chain