Miriam Estevez

Miriam Estevez
Centro de Fisica Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Querétaro, México · Ingeniería Molecular de Materiales

PhD

About

98
Publications
22,332
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
1,297
Citations

Publications

Publications (98)
Article
In the present work, ZnO nanostructures with flower morphology were synthesized and self-assembled by a green approach using an Aloysia triphylla leaves extract. The extract acted as a reducing and stabilizing agent. Moreover, the Aloysia triphylla extract showed the ability to order the nanostructures and form a flower-like arrangement. The format...
Article
Carbon dots (CDs) synthesized using Cinchona pubescens Vahl from the hydrothermal method displayed blue emission radiation, pH dependency, homogeneous sizes, colloidal stability in water, and antibacterial features. They consist of graphene oxide and reduced graphene oxide, attributed to the antioxidant species extracted from the Cinchona pubescens...
Article
Full-text available
Significant advancement in the field of nanotechnology has raised the possibility of applying potent engineered biocompatible nanomaterials within biological systems for theranostic purposes. Titanium dioxide (titanium(IV) oxide/titania/TiO 2 ) has garnered considerable attention as one of the most extensively studied metal oxides in clinical appli...
Article
Full-text available
The recent periodic influx of massive quantities of pelagic Sargassum spp. (sargasso) into the Caribbean has posed ecological, social, and economic challenges to the region. Sustainable use of the biomass is crucial to mitigate negative impacts of beached algae. The current uses of sargasso in Mexico are reviewed, and a biorefinery approach is prop...
Article
This work presents an assessment of the mechanical adhesion and corrosion resistance of the hybrid PMMA-SiO2 coatings applied to an X52 steel substrate. The hybrid composite coating was obtained by dispersing the nanoparticles of SiO2 into a polymeric matrix of PMMA in concentrations of 1.0 wt.%. The study of corrosion behavior in synthetic seawate...
Article
Full-text available
Sargassum species-based extracts were used to carry out the synthesis of homogeneous gold nanoparticles. Various techniques were used to determine the characteristics and composition of the nanoparticles. The UV-Vis results showed that the 50% water/ethanol extract had the most reducing agents and stabilizers. Therefore, this type of extract was us...
Article
Full-text available
In recent years, the food, pharmacy, and cosmetic industries have focused on the search of natural compounds with antimicrobial and antioxidant properties; commonly, these compounds are obtained from Kingdom plantae. The aim of the present work is comparing antibacterial and antioxidant capacity of Annona cherimola Mill leaves, using different extr...
Article
Full-text available
This work reports, for the first time, the synthesis of silver nanoparticles using extracts of the species of Sargassum natans and Sargassum fluitans (AgNPs-S). Their antibacterial and catalytic properties are compared with silver nanoparticles obtained by chemical synthesis (AgNPs-C). The characterization of AgNPs-S and AgNPs-C was carried out usi...
Article
This research aims to provide an alternative eco-friendly way to obtain silver species and assess their bactericidal activity. This study reports the synthesis of Ag2O nanoparticles and Ag nanoparticles reduced with a green synthesis method, using a low-cost and commercial Aloe vera extract. The crystalline phases of Ag and Ag2O nanoparticles were...
Article
Some public institutions in Mexico are combining corrosion research with environmental considerations. Therefore, our research group approached the specific goal of developing new corrosion-resistant materials (paints or coatings) for marine environments, where wave energy is obtained. Hybrid coatings were prepared using polymethylmethacrylate (PMM...
Article
Full-text available
This work presents the results obtained in the design and manufacture of a simple, economic and ecological filter based on Sargassum spp. (Sspp), consisting of the species S. natans and S. fluitans, for the elimination of organic and inorganic toxic substances. The main objective is to make use of Sspp, as the massive amounts of this alga arriving...
Article
Full-text available
Detection and quantification of diverse analytes such as molecules, cells receptor and even particles and nanoparticles, play an important role in biomedical research, particularly in electrochemical sensing platform technologies. In this study, gold nanoparticles (AuNPs) prepared by green synthesis from Sargassum sp. were characterized using ultra...
Article
Full-text available
Since late 2014, the Mexican Caribbean coast has periodically received massive, atypical influxes of pelagic Sargassum spp. (sargasso). Negative impacts associated with these influxes include mortality of nearshore benthic flora and fauna, beach erosion, pollution, decreasing tourism and high management costs. To understand the dynamics of the sarg...
Article
In this work, the formation of Cu@Pd core-shell nanoparticles was studied by optimizing the reduction of Cu2+ to Cu0 used as cores, and by increasing the amount of Pd precursor, labelling these materials as Cu@Pd I to IV, respectively. X-ray diffraction, UV-vis tests, and X-ray photoelectron spectroscopy (XPS) revealed the formation and progressive...
Article
In this work, gold nanomaterials were obtained using aqueous extracts of black carrots varying the molar ratio between the extract and the gold precursor salt (1:10, 1:5 and 2:5). Additionally, Au nanoparticles were obtained by the Turkevich method as reference material (Au Turkevich). Transmission electron micrographs indicated that a 1:5 ratio al...
Article
Full-text available
In this study, new polyurethanes (PUs) were prepared by using inulin and polycaprolactone as polyols. Their structure and morphology were determined by Fourier transform infrared spectroscopy (FTIR), Raman dispersive spectroscopy, Nuclear magnetic resonance spectroscopy (1H NMR and 13C NMR), and scanning electron microscopy (SEM), whereas their mec...
Article
Full-text available
A series of twenty segmented poly(ester-urethane)s (PEUs) were synthesized, by the reaction of four different macrodiols derived from ε-caprolactone (CL) and 1,8-octanediol (Oct), 1,6−hexamethylene diisocyanate (HDI), and three different carotenoids, (3R,3´R,6´R)−lutein (1) obtained from a renewable source such as marigold (Tagetes erecta L.), (3R,...
Article
Full-text available
The demand for hydrophobic polymer-based protective coatings to impart high corrosion resistance has increased recently. The increase of the hydrophobicity in a hybrid coating is a new challenge, for that reason and in order to protect a metallic surface of oxidant agents, a poly (methyl methacrylate) (PMMA) coating with the addition of a different...
Article
Full-text available
Phenolic compounds, obtained from plants are important in the food, biomaterial and pharmaceutical industries; however current extraction methods, such as Soxhlet (solid-liquid) extraction, liquid-liquid extraction, microwave-assisted extraction, and ultrasonic extraction (USE), have the disadvantages of large processing times, contamination by sol...
Article
Eysenhardtia polystachya (EP) is an endemic Mexican plant that has been widely studied for its antidiabetic, antibacterial, and antioxidant properties. Several studies had reported the main components of EP, but their fluorescence properties had not been broadly studied. In a previous study we obtained extracts with different composition from this...
Article
This study focuses in the TiO 2 /Al 2 O 3 powders synthesized by the sol-gel at low vacuum atmosphere, incorporated to polycaprolactone polymer. The corrosion study of coating was realized by electrochemical techniques. The precursors for synthesis of TiO 2 /Al 2 O 3 powders were titanium and aluminum isopropoxides. The obtained powders were sinter...
Article
Full-text available
The synthesis and applications of anisotropic nanostructures have attracted much attention in the last decade. The nanoflower-type structures are one of the nanomaterials with anisotropic structures most investigated because of owing to high densities of edges, corners, and stepped atoms present on their nano-petals. Here, silver nanoparticles obta...
Article
Full-text available
In this work, we are proposing the green synthesis of gold nanoparticles (AuNPs) using aqueous extracts of A. triphylla and evaluating their antibacterial and catalytic properties. Characterization was performed by UV–Vis and FT-IR spectroscopies, X-ray diffraction, and transmission electron microscopy (TEM). Antibacterial activity of AuNPs was ana...
Article
Silver nanoparticles (AgNPs) have potential applications in several fields, mainly when they are synthesized by a green method. In the present work, the photocatalytic and antibacterial properties of silver nanoparticles biosynthesized using aqueous extracts of a variety of Eriobotrya japonica were investigated. The effects on the nanoparticles cha...
Article
Full-text available
Paulownia tomentosa (P. tomentosa) is a hardwood tree that has economic and scientific relevance but has no use as food. For that reason, we selected it to conduct a study on the synthesis of silver nanoparticles (AgNPs) using hydroalcoholic extracts from its leaves. Phytochemical sources had been widely used as reducing agents for synthesis of nan...
Article
An easy green chemistry method was developed for the biosynthesis of gold nanoparticles using different extracts of arantho (Kalanchoe daigremontiana), a medicinal plant commonly used in traditional medicine for cancer treatment. Gold nanoparticles were obtained by a simple bio-reduction process using arantho extracts with different polarities. Lig...
Article
Full-text available
Strength and biocompatibility of composite materials (using a polymer matrix) are used in medicine for various devices such as prostheses and marker clips (biomarkers). Marker clips indicate the site of a lesion in the body, specifically for breast cancer diagnosis or treatment. In general, marker clips are made of steel or titanium, but lately, ma...
Article
Full-text available
The present study reports the green synthesis of silver nanoparticles (AgNṔs) using Cynara cardunculus leaf extract in aqueous media. The silver ions reduction was carried out by the antioxidant component presents in the Cynara cardunculus. Transmission electron micrographs revealed that the synthesized AgNṔs exhibits semi-spherical morphology and...
Article
Full-text available
Anthocyanins are used for food coloring due their low toxicity and health benefits. They are extracted from different sources, but black carrot has higher anthocyanin content compared with common fruits and vegetables. Here, we study alcoholic anthocyanin extracts from black carrot to enhance their stability. The objective of our research is to det...
Chapter
Textile industry produces large quantities of wastewater containing several chemicals (used for preparing, purifying, coloring and finishing textile products). Different treatments methods must be used in stages to safely discharge textile effluents. One of main pollutants of these effluents is textile dye, which has been removed by adsorption. Chi...
Article
Magnetic nanoparticles (MNPs) have demonstrated their potential in a wide variety of biomedical applications including in tumour hyperthermia. However, highly reactive nature and aggregation affinity of these nanostructures are the principal limitations for such applications. To overcome these limitations, those MNPs should be covered with an inert...
Article
Full-text available
Silver-doped hydroxyapatite (Ag-HAP) was obtained by green synthesis route. The dopant silver nanoparticles (AgNPs) were obtained by biosynthesis based on Melissa officinalis extract. This research is focused on the characterization and the use of the nontoxic and environment-friendly Ag-HAP nanocomposite. The structural and morphological character...
Article
Traces of certain heavy metals are crucial for the metabolism of living beings, but poisoning occurs when their concentration increases. On the other hand, heavy metals such as lead, mercury, and cadmium lack functionality in higher organisms, resulting in considerable toxicity. Their long-term persistence is an environmental issue, being adsorptio...
Article
The model and methodology for estimating diffusion-controlled rate coefficients for the methyl methacrylate polymerization system reported in Parts I and II of this series is extended to include the chain transfer reaction to an agent (CTA). Theoretical and experimental results exhibit minima in the rate of polymerization curves at low conversions...
Article
Full-text available
Downstream waste from industry and other industrial processes could increase concentration of heavy metals in water. These pollutants are commonly removed by adsorption because it is an effective and economical method. Previously, we reported adsorption capacity of a chitosan/polyurethane/titanium dioxide (TiO2) composite for three ions in a dynami...
Article
The styrene (St) emulsion polymerization using Aerosol MA80 as surfactant and in the presence of sodium styrene sulfonate (NaSS) was studied. The effect of NaSS content was assessed using MA80 concentrations below and at the critical micellar concentration. It was found that at the higher NaSS and MA80 contents, the number of particles (N) reaches...
Article
Full-text available
The exceptional properties of the silver nanoparticles offer several applications in the biomedicine field. The development of antibiotics which are clinically useful against bacteria and drug resistant microorganisms, it is one of the main approaches of silver nanoparticles. However, it is necessary to develop environmentally friendly methods for...
Article
Full-text available
Ag-based bimetallic core–shell nanoplates have received much attention in catalysis, surface-enhanced Raman scattering (SERS), and sensing applications. However, control over the synthesis of core–shell nanostructures still remains a challenge. Herein, we present a facile, seed-mediated synthesis of bimetallic or multimetallic AgM (M = Au, Pt, and...
Article
Full-text available
In a previous work, we obtained a betalain red dye from Beta vulgaris L. (beet) encapsulated with tetraethyl orthosilicate (TEOS) and studied its stabilities against changes of UV light, pH, and temperature. In the current research, we prepared betalain dyes from B. vulgaris L. and Myrtillocactus geometrizans (bilberry cactus), then we studied the...
Article
Full-text available
New diagnostic techniques for breast cancer detection have been developed and improved, in order to increase patient life expectancy. These techniques were emphasized in early detection of tumors with smaller dimensions, providing a better prognosis. Along with these new methods, it is necessary to propose training devices or tools to support healt...
Article
Currently, nanomaterials had been used for several applications; one of them is as bio-markers. These nanomaterials contain fluorescent compounds as effective indicators for imaging and other applications in Biotechnology. In previous studies, we proposed a functionalized nanomaterial-based biomarker from silica and Eysenhardtia Polystachia, a medi...
Article
Full-text available
This study reports on the rheology of the gelation kinetics of raw chitosan (CTS) solutions (2% w/v) produced by enzymatic hydrolysis of urea at different urea concentrations (40, 50, 60, 80, and 100 mM) in the presence of urease at 1 U/mL. Viscoelastic parameters and pH values were evaluated during gelation process and the rheological properties o...
Article
Full-text available
The surfactant-free styrene emulsion polymerization (EP) in the presence of sodium styrene sulfonate (NaSS) was experimentally studied. It was observed that as the NaSS content is higher the number of particles (N) and the breath of the particle size distributions increases. Although EP’s were performed without added surfactant, the N values obtain...
Conference Paper
Full-text available
procesos, tales como acidez y temperaturas requeridas en diferentes aplicaciones industriales. Se caracterizan por poseer alta eficiencia como adsorbente, baja resistencia a la difusión, así como facilidad de remoción y control en sus reacciones. El objetivo del presente trabajo fue inmovilizar una xilanasa en un soporte magnético a base de quitosa...
Article
BACKGROUND For almost three decades, heavy metal pollution has been studied and several treatment techniques have been proposed. Nevertheless, this contamination in wastewater is still a severe problem. In our study, Cd (II), Pb (II) and Al (III) metal ions removal was evaluated, using a chitosan-TiO2-polyurethane based composite. Composite synthes...
Article
Despite the significant advances in the meniscus tissue engineering field, it is difficult to recreate the complex structure and organization of the collagenous matrix of the meniscus. In this work, we developed a meniscus prototype to be used as substitute or scaffold for the regeneration of the meniscal matrix, recreating the differential morphol...
Article
Full-text available
The synthesis of α -Fe 2 O 3 -Ag bimetallic nanoparticles using a novel and simplified route is presented in this work. These hybrid nanoparticles were produced using a modification of the chemical reduction method by sodium borohydride (NaBH 4 ). Fe(III) chloride hexahydrate (FeCl 3 ·6H 2 O) and silver nitrate (AgNO 3 ) as precursors were employed...
Article
Full-text available
A novel, simple and inexpensive modification method using TEOS to increase the UV light, pH and temperature stability of a red-beet-pigment extracted from Beta vulgaris has been proposed. The effects on the molecular structure of betalains were studied by FTIR spectroscopy. The presence of betacyanin was verified by UV-Vis spectroscopy and its degr...
Conference Paper
Full-text available
The performance of a new dye-sensitized solar cells (DSSCs) based in a natural dye extracted from Insect products Dactylopius coccus Costa (Homoptera, Dactylopiidae) Pigments, is reported. The performance of this solar cell was compared with cells prepared using a dye from Beta vulgaris extract. The solar cells were electrically characterized and c...
Article
The kinetics of chemical transformation during the yogurt production was obtained using micro-Raman spectroscopy: Raman spectra were obtained as a function of the incubation time in the fermentation process from milk to yogurt. The milk fermentation by the lactic acid bacteria produces morphological, chemical and textural changes. The chemical tran...
Article
Full-text available
Polyurethane-based micro- and nano-hybrid composites were produced with controlled porosity to be used as obturation materials. In addition to hydroxyapatite (HAp) micro-particles in the composites, two different ceramics particle types were also added: alumina micro-particles and silica nano-particles. Particles of different sizes provide the mate...
Article
Full-text available
Hybrid dental materials were designed with controlled porosity and improved tribological and mechanical properties. These materials are based on hydroxyapatite (HAp) and reinforced with two different types of ceramic particles, alumina and silica, to support the high stresses and the continuous scratching produced during mastication. The agglutinan...
Article
New TiO2-based organic–inorganic porous hybrid materials were developed for color degradation and tested in azo-compounds aqueous solution. Porous composite materials, with pore size between 100 and 200 μm and pore volume fraction between 62% and 76%, were synthesized using micro-particles of TiO2 in anatase phase agglutinated with solvent-free, mo...
Article
Full-text available
Dye-Sensitized Solar Cells (DSSCs), based on TiO(2) and assembled using a dye from Beta vulgaris extract (BVE) with Tetraethylorthosilicate (TEOS), are reported. The dye BVE/TEOS increased its UV resistance, rendering an increase in the cell lifetime; the performance of these solar cells was compared to those prepared with BVE without TEOS. The eff...