Anayansi Estrada Monje | CIATEC, AC (original) (raw)

Papers by Anayansi Estrada Monje

Chemosensors, Feb 9, 2024

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Applied Sciences

This research aims to analyze and optimize the antifungal property of a composite material made o... more This research aims to analyze and optimize the antifungal property of a composite material made of polyurethane (PUR) and silver nanoparticles (AgNPs) against the fungus Trichophyton rubrum to find the optimal parameters that allow the highest inhibition of the fungal growth to be used in healthcare aimed at the population vulnerable to fungal infections, such as people suffering from diabetes mellitus, thus creating an opportunity for the generation of antifungal products for healthcare applications. This study analyzes the effect of three variables on the antifungal properties of the composite material: nanoparticle size, concentration, and the application of an ultrasonic treatment as a method to aid the dispersion of the AgNPs into PUR matrix. The proposed methodology includes tests in accordance with a standar to evaluate the growth inhibition of the fungi on a culture medium. A categorical logistic regression model was adjusted from 23 factorial design with five replicates, wh...

Journal of King Saud University - Engineering Sciences

Chemosensors

The importance of biomarker quantification in technology cannot be overstated. It has numerous ap... more The importance of biomarker quantification in technology cannot be overstated. It has numerous applications in medical diagnostics, drug delivery, and the timely implementation of prevention and control strategies for highly prevalent diseases worldwide. However, the discovery of new tools for detection has become increasingly necessary. One promising avenue is the use of perovskite-based materials, which exhibit excellent catalytic activity and redox properties. These make them ideal candidates for the development of electrochemical sensors. In this review, the advances of purely non-enzymatic electrochemical detection of bio-analytes, with ABO3 perovskite form, are presented. The work allows the visualization of some of the modifications in the composition and crystal lattice of the perovskites and some variations in the assembly of the electrodes, which can result in systems with a better response to the detection of analytes of interest. These findings have significant implicati...

Investigación y ciencia de la Universidad Autónoma de Aguascalientes, Jan 31, 2023

Los microplásticos (MPs) constituyen un serio tema ambiental de la sociedad actual, producto del ... more Los microplásticos (MPs) constituyen un serio tema ambiental de la sociedad actual, producto del modo de vida moderno en el que todo ocurre a gran velocidad y donde los productos plásticos de un solo uso se han acumulado en todo el planeta. En este trabajo de revisión, se plantea la situación actual en cuestión de caracterización y las mejoras que son necesarias para su optimización. Tambien se discuten los efectos de los MPs sobre el medio ambiente (agua, tierra y aire), las redes tróficas y los mecanismos a través de los cuales se pueden transferir de microorganismos a seres superiores, así como su efecto sobre el ser humano.

Revista Mexicana De Ingenieria Quimica, May 17, 2016

Journal of Chemistry, 2019

The removal of chemical oxygen demand (COD), total organic carbon (TOC), turbidity, and chromium ... more The removal of chemical oxygen demand (COD), total organic carbon (TOC), turbidity, and chromium content from tannery wastewater at different stages of the process was experimentally investigated using electrocoagulation (EC) with iron and aluminium electrodes. In the EC of the beamhouse wastewater (S1), the effects of initial pH and current density were analyzed and electrical energy consumption was determined. The COD and TOC in the solution were effectively removed, with an initial pH 7.0, using either metallic electrode. With a current density of 28 mA/cm2 for an electrolysis procedure of 60 minutes, the removal efficiency of COD and TOC was 72% and 57% with aluminium electrodes and 69% and 60% with iron electrodes, respectively. The minimum energy consumption for the highest COD and TOC removal was 0.37 and 0.69 kWh/m3 when employing iron or aluminium electrodes, respectively. At the optimal conditions, removal efficiencies close to 100% for turbidity and chromium content for w...

Revista Mexicana de Ingeniería Química, 2016

Progress in Rubber, Plastics and Recycling Technology

The effect of natural rubber (NR) on the mechanical and performance properties of ground tire rub... more The effect of natural rubber (NR) on the mechanical and performance properties of ground tire rubber (GTR) has been investigated. The mechanical properties of vulcanized GTR/NR blends were determined in a universal testing machine. It was found a decreasing in the mechanical properties of the GTR/NR blends as the number of re-vulcanization processes increases. This behavior was attributed to the decrease in the concentration on GTR in the vulcanized GTR/NR blend with respect to the next one, and to a structural net degradation into the re-vulcanized GTR/NR blend due to the reversion process (over vulcanization). In the loss modulus charts was observed that the peaks of the curves got smaller and wide as the re-vulcanization process increased, due to the mechanical loses and elastic gains of the GTR/NR re-vulcanized blends. On the other hand, in the performance results was found that the cut growth values of Flexion Ross were more affected by the thickness of the plaque of vulcanized...

Polymers

The structural modification of biopolymers is a current strategy to develop materials with biomed... more The structural modification of biopolymers is a current strategy to develop materials with biomedical applications. Silk fibroin is a natural fiber derived from a protein produced by the silkworm (Bombyx mori) with biocompatible characteristics and excellent mechanical properties. This research reports the structural modification of silk fibroin by incorporating polyaniline chain grafts through a one-pot process (esterification reaction/oxidative polymerization). The structural characterization was achieved by 1H-NMR and FT-IR. The morphology was studied by scanning electron microscopy and complemented with thermogravimetric analysis to understand the effect of the thermal stability at each step of the modification. Different fibroin silk (Fib): polyaniline (PAni) mass ratios were evaluated. From this evaluation, it was found that a Fib to PAni ratio of at least 1 to 0.5 is required to produce electroactive polyaniline, as observed by UV-vis and CV. Notably, all the fibroin-g-PAni s...

Molecules

Establishing the structure–property relationships of monomers and polymers via theoretical chemis... more Establishing the structure–property relationships of monomers and polymers via theoretical chemistry is vital for designing new polymer structures with a specific application. Developing bifunctional monomers with selective polymerizable sites is one of the strategies employed to obtain complex polymeric systems. In this work, a theoretical study on anilinium 2-acrylamide-2-methyl-1-propanesulfonate (ani-AMPS) and anilinium 4-styrenesulfonate (ani-SS) monomers and their respective doped polyaniline dimer (PAni-d AMPS or PAni-d SS) was performed. The study focused on understanding the susceptibility of the vinyl group to a radical attack and the conformation changes resulting from the coordinated covalent bond between sulfonate and aniliniun. Applying Density Functional Theory with the B3LYP functional and a basis set of 6 − 31 + G(d,p), the structures of the ani-AMPS, ani-SS, PAni-d AMPS, and PAni-d SS were optimized, and the different chemical descriptors were determined. The simul...

Progress in Rubber, Plastics and Recycling Technology

The effect of natural rubber (NR) on mechanical, chemical and thermal properties of ground tire r... more The effect of natural rubber (NR) on mechanical, chemical and thermal properties of ground tire rubber (GTR) was investigated. Mechanical and thermal properties of GTR/NR vulcanized blends were determined with a universal testing machine and a dynamic mechanical analyzer (DMA). The molecular cross-linking density was determined by molecular swelling in toluene. Presents results indicate that the carbon black embedded in the GTR interior phase of the GTR/NR re-vulcanized blends, did not participate in the NR phase molecular motion restriction. The blends of GTR/NR showed the phenomenon known as reversion, leading a decreasing of the mechanical properties, that could be attributed of the degradation of the interphases (GTR/NR) n+j, j=1,2,3,…. On the other hand, the Cole-Cole charts of the GTR/NR vulcanized blends changed from a semicircular to an irregular form as the NR concentration increases, imposing the heterogeneity of the blend. In addition, in the Cole-Cole charts of GTR/NR vu...

International Journal of Molecular Sciences

In this research, a brush-like polyaniline (poly(2-acrylamide-2-methyl-1-propanesulfonate)-g-poly... more In this research, a brush-like polyaniline (poly(2-acrylamide-2-methyl-1-propanesulfonate)-g-polyaniline)-b-poly(N-vinylcarbazole) (BL PAni) was developed as a strategy to overcome the limited processability and dedoping above pH 4 of conventional polyaniline (PAni). For the BL PAni synthesis, RAFT polymerization (homopolymer), RAFT-mediated surfactant-free emulsion polymerization (block copolymer), and interfacial oxidative polymerization were applied to graft the PAni chains. NMR and FT-IR spectroscopies were performed to confirm the structural elucidation of the reaction pathways, while the thermal properties were analyzed by TGA and DSC. Notably, the BL PAni presents absorption throughout the visible region and up to the near-infrared, showing dedoping resistance at up to 80 °C and at a neutral pH. The absorption range of the BL PAni, block copolymer, and homopolymer were studied by UV–Vis spectroscopy in solid-state and dispersion/solution, highlighting BL PAni and poly(anilini...

Experimental conditions to recover chromium salts from the leather shavings were investigated in ... more Experimental conditions to recover chromium salts from the leather shavings were investigated in this project. The salt was recovered by an acid treatment of the chromium cake and its later neutralization with a strong base. Process optimal conditions for the salt recovery was determinate, once the salt was recovered its efficiency as a re tannery agent on a pilot level was tested.

Carbohydrate Polymers, 2007

... OH) with certain kinds of reagents such as silanes (Coutinho et al., 1998, Redondo et al., 20... more ... OH) with certain kinds of reagents such as silanes (Coutinho et al., 1998, Redondo et al., 2002 and Rong et al., 2001), acyl halogenures (Chuavelon et al., 1999, Nair et al., 2001, Sun et al., 2001, Thiebaud and Borredon, 1995 and Thiebaud et al., 1997), isocianates (Ellis and O ...

Revista Iberoamericana de Polímeros, 2012

ABSTRACT Poly(ethyleneterephtalate), PET, is an important material which is used largely in the p... more ABSTRACT Poly(ethyleneterephtalate), PET, is an important material which is used largely in the production of soft drinks and mineral water bottles. There are few applications for less purified grades of recycled PET. The aim of the current work is to investigate the depolymerization of PET waste to produce mainly bis(hydroxyethyl) terephtalate, BHET, by a catalyzed glycolysis carried out using excess of ethylene glycol in the presence of different catalysts as zinc and magnesium acetates. The glycolysis reactions have been made with different glycols, namely propylene glycol, diethylene glycol and ethylene glycol. The BHET obtained was separated by distillation and re-crystallized until a quite pure crystalline form was obtained. The product was analyzed by FT-IR and GC-mass spectra and by TGA and DSC thermal analysis.

Journal of Composite Materials, 2013

The composites were fabricated under a variety of different process conditions, ranging from a bl... more The composites were fabricated under a variety of different process conditions, ranging from a blend of a low-density polyethylene reinforced with agave bagasse fibers at concentrations of 5, 10 up to 20 wt%. The theoretical and experimental moduli were determined in conjunction with the fiber degradation. The results show that the moduli of the composites increased with fiber content but decreased linearly with increasing processing temperatures. The calculated theoretical module with the Cox model is significantly greater than that experimentally obtained due to the fiber degradation, poor interfacial fiber/polymer interaction, and structural defects in the interior of the composite generated by the thermal conditions. Thermogravimetric analysis shows an unexpected three-stage process of degradation of the fiber in the temperature range of 225–290℃.

Polymers

This research focused on the development of biomaterials based on cassava starch and corn starch ... more This research focused on the development of biomaterials based on cassava starch and corn starch and on the effect of the incorporation of polycaprolactone (PCL) on the thermal and thermomechanical properties of the blends. The results indicated partial compatibility in the blends, especially with cassava starch at a content of 20 wt% as reflected by the maintenance of tensile strength and elongation. In addition, the changes in the crystal quality of PCL and the displacement of the absorption bands of the carbonyl groups of PCL in the infrared (989–1000 cm−1), attributed to the formation of hydrogen bonds between these groups and the hydroxyl groups of starches, were also associated with compatibility. It was observed that the crystallinity of PLC in the presence of cassava and corn starch was 38% and 62%, respectively; a crystallinity greater than that of PCL was related to an improved nucleation at the interface. Based on these properties, the blends are expected to be functional...

Chemosensors, Feb 9, 2024

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Applied Sciences

This research aims to analyze and optimize the antifungal property of a composite material made o... more This research aims to analyze and optimize the antifungal property of a composite material made of polyurethane (PUR) and silver nanoparticles (AgNPs) against the fungus Trichophyton rubrum to find the optimal parameters that allow the highest inhibition of the fungal growth to be used in healthcare aimed at the population vulnerable to fungal infections, such as people suffering from diabetes mellitus, thus creating an opportunity for the generation of antifungal products for healthcare applications. This study analyzes the effect of three variables on the antifungal properties of the composite material: nanoparticle size, concentration, and the application of an ultrasonic treatment as a method to aid the dispersion of the AgNPs into PUR matrix. The proposed methodology includes tests in accordance with a standar to evaluate the growth inhibition of the fungi on a culture medium. A categorical logistic regression model was adjusted from 23 factorial design with five replicates, wh...

Journal of King Saud University - Engineering Sciences

Chemosensors

The importance of biomarker quantification in technology cannot be overstated. It has numerous ap... more The importance of biomarker quantification in technology cannot be overstated. It has numerous applications in medical diagnostics, drug delivery, and the timely implementation of prevention and control strategies for highly prevalent diseases worldwide. However, the discovery of new tools for detection has become increasingly necessary. One promising avenue is the use of perovskite-based materials, which exhibit excellent catalytic activity and redox properties. These make them ideal candidates for the development of electrochemical sensors. In this review, the advances of purely non-enzymatic electrochemical detection of bio-analytes, with ABO3 perovskite form, are presented. The work allows the visualization of some of the modifications in the composition and crystal lattice of the perovskites and some variations in the assembly of the electrodes, which can result in systems with a better response to the detection of analytes of interest. These findings have significant implicati...

Investigación y ciencia de la Universidad Autónoma de Aguascalientes, Jan 31, 2023

Los microplásticos (MPs) constituyen un serio tema ambiental de la sociedad actual, producto del ... more Los microplásticos (MPs) constituyen un serio tema ambiental de la sociedad actual, producto del modo de vida moderno en el que todo ocurre a gran velocidad y donde los productos plásticos de un solo uso se han acumulado en todo el planeta. En este trabajo de revisión, se plantea la situación actual en cuestión de caracterización y las mejoras que son necesarias para su optimización. Tambien se discuten los efectos de los MPs sobre el medio ambiente (agua, tierra y aire), las redes tróficas y los mecanismos a través de los cuales se pueden transferir de microorganismos a seres superiores, así como su efecto sobre el ser humano.

Revista Mexicana De Ingenieria Quimica, May 17, 2016

Journal of Chemistry, 2019

The removal of chemical oxygen demand (COD), total organic carbon (TOC), turbidity, and chromium ... more The removal of chemical oxygen demand (COD), total organic carbon (TOC), turbidity, and chromium content from tannery wastewater at different stages of the process was experimentally investigated using electrocoagulation (EC) with iron and aluminium electrodes. In the EC of the beamhouse wastewater (S1), the effects of initial pH and current density were analyzed and electrical energy consumption was determined. The COD and TOC in the solution were effectively removed, with an initial pH 7.0, using either metallic electrode. With a current density of 28 mA/cm2 for an electrolysis procedure of 60 minutes, the removal efficiency of COD and TOC was 72% and 57% with aluminium electrodes and 69% and 60% with iron electrodes, respectively. The minimum energy consumption for the highest COD and TOC removal was 0.37 and 0.69 kWh/m3 when employing iron or aluminium electrodes, respectively. At the optimal conditions, removal efficiencies close to 100% for turbidity and chromium content for w...

Revista Mexicana de Ingeniería Química, 2016

Progress in Rubber, Plastics and Recycling Technology

The effect of natural rubber (NR) on the mechanical and performance properties of ground tire rub... more The effect of natural rubber (NR) on the mechanical and performance properties of ground tire rubber (GTR) has been investigated. The mechanical properties of vulcanized GTR/NR blends were determined in a universal testing machine. It was found a decreasing in the mechanical properties of the GTR/NR blends as the number of re-vulcanization processes increases. This behavior was attributed to the decrease in the concentration on GTR in the vulcanized GTR/NR blend with respect to the next one, and to a structural net degradation into the re-vulcanized GTR/NR blend due to the reversion process (over vulcanization). In the loss modulus charts was observed that the peaks of the curves got smaller and wide as the re-vulcanization process increased, due to the mechanical loses and elastic gains of the GTR/NR re-vulcanized blends. On the other hand, in the performance results was found that the cut growth values of Flexion Ross were more affected by the thickness of the plaque of vulcanized...

Polymers

The structural modification of biopolymers is a current strategy to develop materials with biomed... more The structural modification of biopolymers is a current strategy to develop materials with biomedical applications. Silk fibroin is a natural fiber derived from a protein produced by the silkworm (Bombyx mori) with biocompatible characteristics and excellent mechanical properties. This research reports the structural modification of silk fibroin by incorporating polyaniline chain grafts through a one-pot process (esterification reaction/oxidative polymerization). The structural characterization was achieved by 1H-NMR and FT-IR. The morphology was studied by scanning electron microscopy and complemented with thermogravimetric analysis to understand the effect of the thermal stability at each step of the modification. Different fibroin silk (Fib): polyaniline (PAni) mass ratios were evaluated. From this evaluation, it was found that a Fib to PAni ratio of at least 1 to 0.5 is required to produce electroactive polyaniline, as observed by UV-vis and CV. Notably, all the fibroin-g-PAni s...

Molecules

Establishing the structure–property relationships of monomers and polymers via theoretical chemis... more Establishing the structure–property relationships of monomers and polymers via theoretical chemistry is vital for designing new polymer structures with a specific application. Developing bifunctional monomers with selective polymerizable sites is one of the strategies employed to obtain complex polymeric systems. In this work, a theoretical study on anilinium 2-acrylamide-2-methyl-1-propanesulfonate (ani-AMPS) and anilinium 4-styrenesulfonate (ani-SS) monomers and their respective doped polyaniline dimer (PAni-d AMPS or PAni-d SS) was performed. The study focused on understanding the susceptibility of the vinyl group to a radical attack and the conformation changes resulting from the coordinated covalent bond between sulfonate and aniliniun. Applying Density Functional Theory with the B3LYP functional and a basis set of 6 − 31 + G(d,p), the structures of the ani-AMPS, ani-SS, PAni-d AMPS, and PAni-d SS were optimized, and the different chemical descriptors were determined. The simul...

Progress in Rubber, Plastics and Recycling Technology

The effect of natural rubber (NR) on mechanical, chemical and thermal properties of ground tire r... more The effect of natural rubber (NR) on mechanical, chemical and thermal properties of ground tire rubber (GTR) was investigated. Mechanical and thermal properties of GTR/NR vulcanized blends were determined with a universal testing machine and a dynamic mechanical analyzer (DMA). The molecular cross-linking density was determined by molecular swelling in toluene. Presents results indicate that the carbon black embedded in the GTR interior phase of the GTR/NR re-vulcanized blends, did not participate in the NR phase molecular motion restriction. The blends of GTR/NR showed the phenomenon known as reversion, leading a decreasing of the mechanical properties, that could be attributed of the degradation of the interphases (GTR/NR) n+j, j=1,2,3,…. On the other hand, the Cole-Cole charts of the GTR/NR vulcanized blends changed from a semicircular to an irregular form as the NR concentration increases, imposing the heterogeneity of the blend. In addition, in the Cole-Cole charts of GTR/NR vu...

International Journal of Molecular Sciences

In this research, a brush-like polyaniline (poly(2-acrylamide-2-methyl-1-propanesulfonate)-g-poly... more In this research, a brush-like polyaniline (poly(2-acrylamide-2-methyl-1-propanesulfonate)-g-polyaniline)-b-poly(N-vinylcarbazole) (BL PAni) was developed as a strategy to overcome the limited processability and dedoping above pH 4 of conventional polyaniline (PAni). For the BL PAni synthesis, RAFT polymerization (homopolymer), RAFT-mediated surfactant-free emulsion polymerization (block copolymer), and interfacial oxidative polymerization were applied to graft the PAni chains. NMR and FT-IR spectroscopies were performed to confirm the structural elucidation of the reaction pathways, while the thermal properties were analyzed by TGA and DSC. Notably, the BL PAni presents absorption throughout the visible region and up to the near-infrared, showing dedoping resistance at up to 80 °C and at a neutral pH. The absorption range of the BL PAni, block copolymer, and homopolymer were studied by UV–Vis spectroscopy in solid-state and dispersion/solution, highlighting BL PAni and poly(anilini...

Experimental conditions to recover chromium salts from the leather shavings were investigated in ... more Experimental conditions to recover chromium salts from the leather shavings were investigated in this project. The salt was recovered by an acid treatment of the chromium cake and its later neutralization with a strong base. Process optimal conditions for the salt recovery was determinate, once the salt was recovered its efficiency as a re tannery agent on a pilot level was tested.

Carbohydrate Polymers, 2007

... OH) with certain kinds of reagents such as silanes (Coutinho et al., 1998, Redondo et al., 20... more ... OH) with certain kinds of reagents such as silanes (Coutinho et al., 1998, Redondo et al., 2002 and Rong et al., 2001), acyl halogenures (Chuavelon et al., 1999, Nair et al., 2001, Sun et al., 2001, Thiebaud and Borredon, 1995 and Thiebaud et al., 1997), isocianates (Ellis and O ...

Revista Iberoamericana de Polímeros, 2012

ABSTRACT Poly(ethyleneterephtalate), PET, is an important material which is used largely in the p... more ABSTRACT Poly(ethyleneterephtalate), PET, is an important material which is used largely in the production of soft drinks and mineral water bottles. There are few applications for less purified grades of recycled PET. The aim of the current work is to investigate the depolymerization of PET waste to produce mainly bis(hydroxyethyl) terephtalate, BHET, by a catalyzed glycolysis carried out using excess of ethylene glycol in the presence of different catalysts as zinc and magnesium acetates. The glycolysis reactions have been made with different glycols, namely propylene glycol, diethylene glycol and ethylene glycol. The BHET obtained was separated by distillation and re-crystallized until a quite pure crystalline form was obtained. The product was analyzed by FT-IR and GC-mass spectra and by TGA and DSC thermal analysis.

Journal of Composite Materials, 2013

The composites were fabricated under a variety of different process conditions, ranging from a bl... more The composites were fabricated under a variety of different process conditions, ranging from a blend of a low-density polyethylene reinforced with agave bagasse fibers at concentrations of 5, 10 up to 20 wt%. The theoretical and experimental moduli were determined in conjunction with the fiber degradation. The results show that the moduli of the composites increased with fiber content but decreased linearly with increasing processing temperatures. The calculated theoretical module with the Cox model is significantly greater than that experimentally obtained due to the fiber degradation, poor interfacial fiber/polymer interaction, and structural defects in the interior of the composite generated by the thermal conditions. Thermogravimetric analysis shows an unexpected three-stage process of degradation of the fiber in the temperature range of 225–290℃.

Polymers

This research focused on the development of biomaterials based on cassava starch and corn starch ... more This research focused on the development of biomaterials based on cassava starch and corn starch and on the effect of the incorporation of polycaprolactone (PCL) on the thermal and thermomechanical properties of the blends. The results indicated partial compatibility in the blends, especially with cassava starch at a content of 20 wt% as reflected by the maintenance of tensile strength and elongation. In addition, the changes in the crystal quality of PCL and the displacement of the absorption bands of the carbonyl groups of PCL in the infrared (989–1000 cm−1), attributed to the formation of hydrogen bonds between these groups and the hydroxyl groups of starches, were also associated with compatibility. It was observed that the crystallinity of PLC in the presence of cassava and corn starch was 38% and 62%, respectively; a crystallinity greater than that of PCL was related to an improved nucleation at the interface. Based on these properties, the blends are expected to be functional...