The search for adsorbent materials with a certain chemical inertness, mechanical resistance, and ... more The search for adsorbent materials with a certain chemical inertness, mechanical resistance, and high adsorption capacity, as is the case with alumina, is carried out with structural or surface modifications with the addition of additives or metallic salts. This research shows the synthesis, characterization, phase evolution and Cd(II) adsorbent capacity of α-Al2O3/Ba-β-Al2O3 spheres obtained from α-Al2O3 nanopowders by the ion encapsulation method. The formation of the Ba-β-Al2O3 phase is manifested at 1500 °C according to the infrared spectrum by the appearance of bands corresponding to AlO4 bonds and the appearance of peaks corresponding to Ba-O bonds in Raman spectroscopy. XRD determined the presence of BaO·Al2O3 at 1000 °C and the formation of Ba-β-Al2O3 at 1600 °C. Scanning electron microscopy revealed the presence of spherical grains corresponding to α-Al2O3 and hexagonal plates corresponding to β-Al2O3 in the spheres treated at 1600 °C. The spheres obtained have dimensions o...
Page 1. THERMAL EVOLUTION OF MICROSTRUCTURE IN A TRIAXIAL CERAMIC BY SEM-IR Simón Y. Reyes López(... more Page 1. THERMAL EVOLUTION OF MICROSTRUCTURE IN A TRIAXIAL CERAMIC BY SEM-IR Simón Y. Reyes López(1), Juan Serrato Rodríguez(1) and Ariosto Medina(1) (1)Instituto de Investigaciones Metalúrgicas, Universidad ...
Lithium niobate-silica fibers were produced by the combination of the sol-gel method and 8 the el... more Lithium niobate-silica fibers were produced by the combination of the sol-gel method and 8 the electrospinning technique. Two sol-gel solutions starting from niobium-lithium ethoxide and 9 tetraethyl orthosilicate were prepared and then mixed with polyvinylpyrrolidone; the solutions 10 were electrospuned in a coaxial setup. The obtained lithium niobate-silica polymeric fibers had 11 approximately 760 nm in diameter. Raman spectroscopy confirmed the composite composition by 12 showing signals corresponding to lithium niobate and silica. Scanning electron microscopy showed 13 coaxial fibers with a diameter of around 330 nm arranged as a fibrillar membrane at 800 °C. At 14 1,000°C the continuous shape of fibers was preserved; the structure is composed of silica and lithium 15 niobate nanoparticles within the fibers. Formation of crystalline lithium niobate and amorphous 16 SiO2 phase was also confirmed by XRD peaks. 17
Progress in the manufacture of scaffolds in tissue engineering lies in the successful combination... more Progress in the manufacture of scaffolds in tissue engineering lies in the successful combination of materials such as bioceramics having properties as porosity, biocompatibility, water retention, protein adsorption, mechanical strength and biomineralization. Hydroxyapatite (HA) is a ceramic material with lots of potential in tissue regeneration, however, its structural characteristics need to be improved for better performance. In this study, silica-hydroxyapatite (SiO2-HA) non-woven ceramic electrospunned membranes were prepared through the sol-gel method. Infrared spectra, scanning electron microscopy and XRD confirmed the structure and composition of composite. The obtained SiO2-HA polymeric fibers had approximately 230±20 nm in diameter and were then sintered at 800°C average diameter decreased to 110±17 nm. Three configurations of the membranes were obtained and tested in vitro, showing that the composite of SiO2-HA fibers showed a high percentage of viability on a fibroblast ...
Currently, nanotechnology is perceived as a promising science that produces materials with divers... more Currently, nanotechnology is perceived as a promising science that produces materials with diverse unique properties at a nanometric scale. Biocompatibility tests of poly-ε-caprolactone nanofibers, embedded with silver nanoparticles manufactured by means of the electrospinning technique, were carried out in Wistar rats to be used as oral dressings for the eradication of bacteria. Solutions of 12.5, 25, 50 and 100 mM of silver nitrate were made using N-dimethylformamide (DMF) and tetrahydrofuran (THF) as reducing solvents with 8% of poly-ε-caprolactone (PCL) polymer. The solutions were electrospun, and the nanofibers obtained in the process were characterized by infrared spectroscopy, Raman spectroscopy, dark field optical microscopy, scanning electron microscopy and X-ray scattering spectroscopy. The nanofibers had an average diameter of 400 ± 100 nm. Once the characterization of the material was done, three implants of each concentration of the nanofibers were formed and placed in ...
A facile strategy for the fabrication of polycaprolactone (PCL) nanofibers containing gold nanopa... more A facile strategy for the fabrication of polycaprolactone (PCL) nanofibers containing gold nanoparticles (AuNPs) is proposed. The method is based on electrospinning nanosuspensions loaded with passivated Au nanoparticles. The optical property of gold nanoparticles synthesized was observed by UV-visible absorption spectra. Morphology and structure of the Au-PCL hybrid nanofibers were characterized by scanning electron microscopy, scanning transmission electron microscopy, and Fourier transformed infrared spectroscopy. The results of investigations by UV-visible and dynamic light scattering confirmed the presence of gold nanoparticles with diameters less than 10 nm. The STEM images show the presence of gold nanoparticles and gold agglomerates with diameter around 30 to 180 nm distributed over the surface of nanofibers, which is likely due to the increased incidence of agglomerations of AuNPs, due to drying process used.
Surface Enhanced on Infrared Absorption (SEIRAS) and Raman Spectroscopy (SERS) are nondestructive... more Surface Enhanced on Infrared Absorption (SEIRAS) and Raman Spectroscopy (SERS) are nondestructive analytic techniques used to detect low concentrations and recognize the fingerprints of molecules. The recognition of the absorption from samples by conventional infrared spectroscopy (IR) via Attenuated Total Reflection (ATR) is difficult for molecules with a low signal strength. However, developed structures with SERS and SEIRAS effect present problems such as high cost, low stability, and low compatibility. Research into new media to obtain greater amplification is largely based on the creation of nanoscale structures with symmetrical arrangements and reproducible distances, resulting in aggregates of nanoparticles that help generate hot spots which are active for amplification. The sol-gel and electrospinning method for the obtention of ceramics provides an alternative means by which to produce said substrates. Fibers of nanometric scale provide an increase of surface area which all...
High doses of antimicrobial agents are a huge threat due to the increasing number of pathogenic o... more High doses of antimicrobial agents are a huge threat due to the increasing number of pathogenic organisms that are becoming resistant to antimicrobial agents. This resistance has led to a search for alternatives. Therefore, this study presents the synthesis and characterization of ZrO2-Ag2O nanoparticles (NPs) by sol-gel. The NPs were analyzed by dynamic light scattering (DLS), UV-visible (UV-vis), Raman and scanning electron microscopy (SEM). The NPs were later evaluated for their antifungal effects against Candidaalbicans, Candida dubliniensis, Candida glabrata, and Candida tropicalis, using disc diffusion and microdilution methods, followed by the viability study. The DLS showed sizes for ZrO2 76 nm, Ag2O 50 nm, and ZrO2-Ag2O samples between 14 and 42 nm. UV-vis shows an absorption peak at 300 nm for ZrO2 and a broadband for Ag2O NPs. Raman spectra were consistent with factor group analysis predictions. SEM showed spherically shaped NPs. The antifungal activity result suggested t...
Researchers are currently looking for materials that are stable, functional, aesthetic, and bioco... more Researchers are currently looking for materials that are stable, functional, aesthetic, and biocompatible without infections. Therefore, there is a great interest in obtaining a material that has a balance between aesthetic, biological, mechanical, and functional factors, which can be used as an infection control material. The addition of hydroxyapatite to alumina make highly bioactive scaffolds with mechanical strength. Biomedical applications require antibacterial properties; therefore, this idea leads to great interest in the development of new synthetic routes of ceramic biomaterials that allow the release of nanoparticles or metal ions. This investigation presents the obtention of alumina-hydroxyapatite spheres doped with silver nanoparticles with antibacterial effect against various Gram-positive and negative bacteria related to drug-resistance infections. The microstructural and spectroscopic studies demonstrate that the spheres exhibit a homogeneous structure and crystal hyd...
New nanocomposite membrane was fabricated by electrospinning. The nanocomposite combines a glass ... more New nanocomposite membrane was fabricated by electrospinning. The nanocomposite combines a glass and hydroxyapatite (HA). This research proposed the incorporation of glass to counteract the brittleness of HA in a composite formed by coaxial fibers which will be used for bone replacement. Calcium phosphate ceramics are used widely for dental and orthopedic reasons, because they can join tightly through chemical bonds and promote bone regeneration. Precursors HA and SiO2 were synthetized through the sol-gel method and then incorporated into a polymeric PVP matrix; later they were processed by coaxial electrospinning to obtain fibers with an average diameter of 538 nm which were characterized with techniques such as Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy, Differential Thermal Analysis and Scanning Electron Microscopy. Chemical and physical characterization of the membranes evidenced fibers in a coaxial disposition with a glass core and hydroxyapatite cover...
Surface Enhanced Infrared Absorption Spectroscopy and Surface Enhanced Raman Spectroscopy are ana... more Surface Enhanced Infrared Absorption Spectroscopy and Surface Enhanced Raman Spectroscopy are analytic techniques that have not been massively adopted since there are issues that still need to be solved with regard to the nature of the signal enhancement substrates used. The sol–gel method for the obtention of ceramics provides an alternative for the production of said substrates. Ceramics are very wear- and heat-resistant, properties that can be used for their regeneration, and through the sol–gel method, ceramics can be produced with high purity as well as can be fashioned in many ways through different techniques, which can be helpful in the pursuit of reproducibility. This paper discusses the different advantages of sol–gel ceramics, their use in the electrospinning technique, and their application in infrared and Raman surface-enhanced spectroscopy.
Surface-enhanced Raman spectroscopy (SERS) and Surface-enhanced infrared absorption spectroscopy ... more Surface-enhanced Raman spectroscopy (SERS) and Surface-enhanced infrared absorption spectroscopy (SEIRAS) are both novel techniques favored by the excitation of surface plasmons onto metal nanostructures. The light emitted from the metal surface couples with the vibrational transitions of molecules in proximity, enhancing its spectral response and leading to more sensitive and effective spectroscopic analysis. The absence of inexpensive and reproducible substrates is among the major impediments to the accurate implementation and optimal performance of the technique. The development of a low-cost active substrate based on silica–hydroxyapatite through sol–gel synthesis and electrospinning is addressed in the present study. Fibers of 512 ± 199 nm diameter were produced after sintering at 1150 °C on the electrospun mats. The fibers are fixed to an indium tin oxide (ITO) glass base for electrodeposition with 10 and 20 mM AgNO3 at 1.5 and 3.3 V at different time periods. Electrodepositio...
Innovative and improved antimicrobial agents by nanotechnology are developed to control and mitig... more Innovative and improved antimicrobial agents by nanotechnology are developed to control and mitigation of resistant microorganisms. Nanoparticles of metals or oxide metals be able to be toxic to bacteria, demonstrating biocidal behaviors at low concentrations. The integration of silver nanoparticles in ceramic matrices has enhanced the antimicrobial performance, resulting in the search for new composites with improved bactericidal properties. The aim of this study was to prepare and characterize hydroxyapatite-silver nanocomposite and evaluate its antimicrobial properties against various Gram-positive and negative bacteria related to drug-resistance infections. Hydroxyapatite nanopowders were produced by sol-gel and silver nanoparticles were synthesized by reduction of Ag+ions with the simple addition of gallic acid. Hydroxyapatite-silver composite (HAp-AgNPs) was prepared by adsorption of AgNPs at several concentrations. The results of UV–visible spectroscopy, dynamic light scatter...
In view of the continuous resistance to antibacterial agents by bacteria and the existing problem... more In view of the continuous resistance to antibacterial agents by bacteria and the existing problems of silver nanoparticles as an antibacterial agent, this study reports on the synthesis of pure zirconium oxide, silver oxide, and ZrO2-Ag2O nanoparticles by sol-gel method. The nanoparticles were analyzed and tested for their antibacterial activity against gram-positive bacteria of Bacillus subtilis, Streptococcus mutans, Staphylococcus aureus, and gram-negative of Escherichia coli, Pseudomonas aeruginosa, and Klebsiella oxytoca. X-ray diffraction showed the monoclinic ZrO2, cubic Ag2O, and peaks corresponding to ZrO2 and Ag2O in their mixed samples. Scanning electron microscopy showed spherically shaped nanoparticles while dynamic light scattering analysis showed ZrO2 (76 nm), Ag2O (50 nm), and ZrO2-Ag2O samples between 14 and 42 nm. The Fourier Transformed Infrared spectroscopy spectra of ZrO2 gave bands at 480 cm−1 to 750 cm−1 (M-O stretching) with Ag2O at 580 cm−1, while ZrO2-Ag2O ...
Currently, the use of sustainable chemistry as an ecological alternative for the generation of pr... more Currently, the use of sustainable chemistry as an ecological alternative for the generation of products or processes, free of polluting substance has assumed a preponderant role. The aim of this work is propose a bioinspired, facile, at low cost, non-toxic and environmentally friendly alternative to obtaining magnetic nanoparticles whit a majority phase of magnetite (Fe3O4). Is important to empathize that the synthesis was based on the chemical reduction through the Cnicus Benedictus extract, whose use as reducing agent has not been reported in the synthesis of iron oxides nanoparticles. In addition, the Cnicus Benedictus is abundant endemic plant in Mexico, with several medicinal properties and a large number of natural antioxidants. The obtained nanoparticles exhibited significant magnetic and antibacterial properties and an enhanced photocatalytic activity. The crystallite size of the Fe3O4 nanoparticles (Fe3O4 NP’s) was calculated by Williamson-Hall method. The photocatalytic pr...
The synthesis of composites with antibacterial properties is of great interest for the developmen... more The synthesis of composites with antibacterial properties is of great interest for the development of new biomedical applications. The antimicrobial properties of silver have been verified against microorganisms such as bacteria, viruses, and fungi; interest in silver has been renewed, so several technologies are currently in development, especially in dental materials. The purpose of this work was to improve the parameters for producing silver-doped alumina spherical beads using sodium alginate as a sacrificial template. Alumina is a biocompatible and thermally stable ceramic, while silver was used for its bactericidal properties. The obtained spheres presented a mean diameter of 2 mm, with an irregular surface and intertwined particles after a sintering process. After electrodeposition, white spheres turned to a dark gray color, demonstrating the presence of silver nanoparticles and fractal silver dendrites on the surface. Spheres were characterized by SEM, FTIR, and XRD. Antimicr...
The search for adsorbent materials with a certain chemical inertness, mechanical resistance, and ... more The search for adsorbent materials with a certain chemical inertness, mechanical resistance, and high adsorption capacity, as is the case with alumina, is carried out with structural or surface modifications with the addition of additives or metallic salts. This research shows the synthesis, characterization, phase evolution and Cd(II) adsorbent capacity of α-Al2O3/Ba-β-Al2O3 spheres obtained from α-Al2O3 nanopowders by the ion encapsulation method. The formation of the Ba-β-Al2O3 phase is manifested at 1500 °C according to the infrared spectrum by the appearance of bands corresponding to AlO4 bonds and the appearance of peaks corresponding to Ba-O bonds in Raman spectroscopy. XRD determined the presence of BaO·Al2O3 at 1000 °C and the formation of Ba-β-Al2O3 at 1600 °C. Scanning electron microscopy revealed the presence of spherical grains corresponding to α-Al2O3 and hexagonal plates corresponding to β-Al2O3 in the spheres treated at 1600 °C. The spheres obtained have dimensions o...
Page 1. THERMAL EVOLUTION OF MICROSTRUCTURE IN A TRIAXIAL CERAMIC BY SEM-IR Simón Y. Reyes López(... more Page 1. THERMAL EVOLUTION OF MICROSTRUCTURE IN A TRIAXIAL CERAMIC BY SEM-IR Simón Y. Reyes López(1), Juan Serrato Rodríguez(1) and Ariosto Medina(1) (1)Instituto de Investigaciones Metalúrgicas, Universidad ...
Lithium niobate-silica fibers were produced by the combination of the sol-gel method and 8 the el... more Lithium niobate-silica fibers were produced by the combination of the sol-gel method and 8 the electrospinning technique. Two sol-gel solutions starting from niobium-lithium ethoxide and 9 tetraethyl orthosilicate were prepared and then mixed with polyvinylpyrrolidone; the solutions 10 were electrospuned in a coaxial setup. The obtained lithium niobate-silica polymeric fibers had 11 approximately 760 nm in diameter. Raman spectroscopy confirmed the composite composition by 12 showing signals corresponding to lithium niobate and silica. Scanning electron microscopy showed 13 coaxial fibers with a diameter of around 330 nm arranged as a fibrillar membrane at 800 °C. At 14 1,000°C the continuous shape of fibers was preserved; the structure is composed of silica and lithium 15 niobate nanoparticles within the fibers. Formation of crystalline lithium niobate and amorphous 16 SiO2 phase was also confirmed by XRD peaks. 17
Progress in the manufacture of scaffolds in tissue engineering lies in the successful combination... more Progress in the manufacture of scaffolds in tissue engineering lies in the successful combination of materials such as bioceramics having properties as porosity, biocompatibility, water retention, protein adsorption, mechanical strength and biomineralization. Hydroxyapatite (HA) is a ceramic material with lots of potential in tissue regeneration, however, its structural characteristics need to be improved for better performance. In this study, silica-hydroxyapatite (SiO2-HA) non-woven ceramic electrospunned membranes were prepared through the sol-gel method. Infrared spectra, scanning electron microscopy and XRD confirmed the structure and composition of composite. The obtained SiO2-HA polymeric fibers had approximately 230±20 nm in diameter and were then sintered at 800°C average diameter decreased to 110±17 nm. Three configurations of the membranes were obtained and tested in vitro, showing that the composite of SiO2-HA fibers showed a high percentage of viability on a fibroblast ...
Currently, nanotechnology is perceived as a promising science that produces materials with divers... more Currently, nanotechnology is perceived as a promising science that produces materials with diverse unique properties at a nanometric scale. Biocompatibility tests of poly-ε-caprolactone nanofibers, embedded with silver nanoparticles manufactured by means of the electrospinning technique, were carried out in Wistar rats to be used as oral dressings for the eradication of bacteria. Solutions of 12.5, 25, 50 and 100 mM of silver nitrate were made using N-dimethylformamide (DMF) and tetrahydrofuran (THF) as reducing solvents with 8% of poly-ε-caprolactone (PCL) polymer. The solutions were electrospun, and the nanofibers obtained in the process were characterized by infrared spectroscopy, Raman spectroscopy, dark field optical microscopy, scanning electron microscopy and X-ray scattering spectroscopy. The nanofibers had an average diameter of 400 ± 100 nm. Once the characterization of the material was done, three implants of each concentration of the nanofibers were formed and placed in ...
A facile strategy for the fabrication of polycaprolactone (PCL) nanofibers containing gold nanopa... more A facile strategy for the fabrication of polycaprolactone (PCL) nanofibers containing gold nanoparticles (AuNPs) is proposed. The method is based on electrospinning nanosuspensions loaded with passivated Au nanoparticles. The optical property of gold nanoparticles synthesized was observed by UV-visible absorption spectra. Morphology and structure of the Au-PCL hybrid nanofibers were characterized by scanning electron microscopy, scanning transmission electron microscopy, and Fourier transformed infrared spectroscopy. The results of investigations by UV-visible and dynamic light scattering confirmed the presence of gold nanoparticles with diameters less than 10 nm. The STEM images show the presence of gold nanoparticles and gold agglomerates with diameter around 30 to 180 nm distributed over the surface of nanofibers, which is likely due to the increased incidence of agglomerations of AuNPs, due to drying process used.
Surface Enhanced on Infrared Absorption (SEIRAS) and Raman Spectroscopy (SERS) are nondestructive... more Surface Enhanced on Infrared Absorption (SEIRAS) and Raman Spectroscopy (SERS) are nondestructive analytic techniques used to detect low concentrations and recognize the fingerprints of molecules. The recognition of the absorption from samples by conventional infrared spectroscopy (IR) via Attenuated Total Reflection (ATR) is difficult for molecules with a low signal strength. However, developed structures with SERS and SEIRAS effect present problems such as high cost, low stability, and low compatibility. Research into new media to obtain greater amplification is largely based on the creation of nanoscale structures with symmetrical arrangements and reproducible distances, resulting in aggregates of nanoparticles that help generate hot spots which are active for amplification. The sol-gel and electrospinning method for the obtention of ceramics provides an alternative means by which to produce said substrates. Fibers of nanometric scale provide an increase of surface area which all...
High doses of antimicrobial agents are a huge threat due to the increasing number of pathogenic o... more High doses of antimicrobial agents are a huge threat due to the increasing number of pathogenic organisms that are becoming resistant to antimicrobial agents. This resistance has led to a search for alternatives. Therefore, this study presents the synthesis and characterization of ZrO2-Ag2O nanoparticles (NPs) by sol-gel. The NPs were analyzed by dynamic light scattering (DLS), UV-visible (UV-vis), Raman and scanning electron microscopy (SEM). The NPs were later evaluated for their antifungal effects against Candidaalbicans, Candida dubliniensis, Candida glabrata, and Candida tropicalis, using disc diffusion and microdilution methods, followed by the viability study. The DLS showed sizes for ZrO2 76 nm, Ag2O 50 nm, and ZrO2-Ag2O samples between 14 and 42 nm. UV-vis shows an absorption peak at 300 nm for ZrO2 and a broadband for Ag2O NPs. Raman spectra were consistent with factor group analysis predictions. SEM showed spherically shaped NPs. The antifungal activity result suggested t...
Researchers are currently looking for materials that are stable, functional, aesthetic, and bioco... more Researchers are currently looking for materials that are stable, functional, aesthetic, and biocompatible without infections. Therefore, there is a great interest in obtaining a material that has a balance between aesthetic, biological, mechanical, and functional factors, which can be used as an infection control material. The addition of hydroxyapatite to alumina make highly bioactive scaffolds with mechanical strength. Biomedical applications require antibacterial properties; therefore, this idea leads to great interest in the development of new synthetic routes of ceramic biomaterials that allow the release of nanoparticles or metal ions. This investigation presents the obtention of alumina-hydroxyapatite spheres doped with silver nanoparticles with antibacterial effect against various Gram-positive and negative bacteria related to drug-resistance infections. The microstructural and spectroscopic studies demonstrate that the spheres exhibit a homogeneous structure and crystal hyd...
New nanocomposite membrane was fabricated by electrospinning. The nanocomposite combines a glass ... more New nanocomposite membrane was fabricated by electrospinning. The nanocomposite combines a glass and hydroxyapatite (HA). This research proposed the incorporation of glass to counteract the brittleness of HA in a composite formed by coaxial fibers which will be used for bone replacement. Calcium phosphate ceramics are used widely for dental and orthopedic reasons, because they can join tightly through chemical bonds and promote bone regeneration. Precursors HA and SiO2 were synthetized through the sol-gel method and then incorporated into a polymeric PVP matrix; later they were processed by coaxial electrospinning to obtain fibers with an average diameter of 538 nm which were characterized with techniques such as Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy, Differential Thermal Analysis and Scanning Electron Microscopy. Chemical and physical characterization of the membranes evidenced fibers in a coaxial disposition with a glass core and hydroxyapatite cover...
Surface Enhanced Infrared Absorption Spectroscopy and Surface Enhanced Raman Spectroscopy are ana... more Surface Enhanced Infrared Absorption Spectroscopy and Surface Enhanced Raman Spectroscopy are analytic techniques that have not been massively adopted since there are issues that still need to be solved with regard to the nature of the signal enhancement substrates used. The sol–gel method for the obtention of ceramics provides an alternative for the production of said substrates. Ceramics are very wear- and heat-resistant, properties that can be used for their regeneration, and through the sol–gel method, ceramics can be produced with high purity as well as can be fashioned in many ways through different techniques, which can be helpful in the pursuit of reproducibility. This paper discusses the different advantages of sol–gel ceramics, their use in the electrospinning technique, and their application in infrared and Raman surface-enhanced spectroscopy.
Surface-enhanced Raman spectroscopy (SERS) and Surface-enhanced infrared absorption spectroscopy ... more Surface-enhanced Raman spectroscopy (SERS) and Surface-enhanced infrared absorption spectroscopy (SEIRAS) are both novel techniques favored by the excitation of surface plasmons onto metal nanostructures. The light emitted from the metal surface couples with the vibrational transitions of molecules in proximity, enhancing its spectral response and leading to more sensitive and effective spectroscopic analysis. The absence of inexpensive and reproducible substrates is among the major impediments to the accurate implementation and optimal performance of the technique. The development of a low-cost active substrate based on silica–hydroxyapatite through sol–gel synthesis and electrospinning is addressed in the present study. Fibers of 512 ± 199 nm diameter were produced after sintering at 1150 °C on the electrospun mats. The fibers are fixed to an indium tin oxide (ITO) glass base for electrodeposition with 10 and 20 mM AgNO3 at 1.5 and 3.3 V at different time periods. Electrodepositio...
Innovative and improved antimicrobial agents by nanotechnology are developed to control and mitig... more Innovative and improved antimicrobial agents by nanotechnology are developed to control and mitigation of resistant microorganisms. Nanoparticles of metals or oxide metals be able to be toxic to bacteria, demonstrating biocidal behaviors at low concentrations. The integration of silver nanoparticles in ceramic matrices has enhanced the antimicrobial performance, resulting in the search for new composites with improved bactericidal properties. The aim of this study was to prepare and characterize hydroxyapatite-silver nanocomposite and evaluate its antimicrobial properties against various Gram-positive and negative bacteria related to drug-resistance infections. Hydroxyapatite nanopowders were produced by sol-gel and silver nanoparticles were synthesized by reduction of Ag+ions with the simple addition of gallic acid. Hydroxyapatite-silver composite (HAp-AgNPs) was prepared by adsorption of AgNPs at several concentrations. The results of UV–visible spectroscopy, dynamic light scatter...
In view of the continuous resistance to antibacterial agents by bacteria and the existing problem... more In view of the continuous resistance to antibacterial agents by bacteria and the existing problems of silver nanoparticles as an antibacterial agent, this study reports on the synthesis of pure zirconium oxide, silver oxide, and ZrO2-Ag2O nanoparticles by sol-gel method. The nanoparticles were analyzed and tested for their antibacterial activity against gram-positive bacteria of Bacillus subtilis, Streptococcus mutans, Staphylococcus aureus, and gram-negative of Escherichia coli, Pseudomonas aeruginosa, and Klebsiella oxytoca. X-ray diffraction showed the monoclinic ZrO2, cubic Ag2O, and peaks corresponding to ZrO2 and Ag2O in their mixed samples. Scanning electron microscopy showed spherically shaped nanoparticles while dynamic light scattering analysis showed ZrO2 (76 nm), Ag2O (50 nm), and ZrO2-Ag2O samples between 14 and 42 nm. The Fourier Transformed Infrared spectroscopy spectra of ZrO2 gave bands at 480 cm−1 to 750 cm−1 (M-O stretching) with Ag2O at 580 cm−1, while ZrO2-Ag2O ...
Currently, the use of sustainable chemistry as an ecological alternative for the generation of pr... more Currently, the use of sustainable chemistry as an ecological alternative for the generation of products or processes, free of polluting substance has assumed a preponderant role. The aim of this work is propose a bioinspired, facile, at low cost, non-toxic and environmentally friendly alternative to obtaining magnetic nanoparticles whit a majority phase of magnetite (Fe3O4). Is important to empathize that the synthesis was based on the chemical reduction through the Cnicus Benedictus extract, whose use as reducing agent has not been reported in the synthesis of iron oxides nanoparticles. In addition, the Cnicus Benedictus is abundant endemic plant in Mexico, with several medicinal properties and a large number of natural antioxidants. The obtained nanoparticles exhibited significant magnetic and antibacterial properties and an enhanced photocatalytic activity. The crystallite size of the Fe3O4 nanoparticles (Fe3O4 NP’s) was calculated by Williamson-Hall method. The photocatalytic pr...
The synthesis of composites with antibacterial properties is of great interest for the developmen... more The synthesis of composites with antibacterial properties is of great interest for the development of new biomedical applications. The antimicrobial properties of silver have been verified against microorganisms such as bacteria, viruses, and fungi; interest in silver has been renewed, so several technologies are currently in development, especially in dental materials. The purpose of this work was to improve the parameters for producing silver-doped alumina spherical beads using sodium alginate as a sacrificial template. Alumina is a biocompatible and thermally stable ceramic, while silver was used for its bactericidal properties. The obtained spheres presented a mean diameter of 2 mm, with an irregular surface and intertwined particles after a sintering process. After electrodeposition, white spheres turned to a dark gray color, demonstrating the presence of silver nanoparticles and fractal silver dendrites on the surface. Spheres were characterized by SEM, FTIR, and XRD. Antimicr...
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