Elsa Gabriela Ordoñez-Casanova

This work presents the effect of synthesis time on morphology and its influence on the optical properties of microwave-assisted carbon nanospheres. To analyze the correlation between the synthesis time and the growth in size of the nanospheres, the morphology of the nanostructures was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Their optical properties were analyzed by UV-Vis spectrophotometry, and the Tauc method was used to estimate the optical band gap. The results reveal that the time variation in the synthesis does have a significant influence on the size, shape, and amount of sample obtained. The optical properties presented slight modifications. With these results, we can provide an easy reproducibility of simple and inexpensive methods to optimize the growth of carbonbased nanoparticles, which can bring advances in the synthesis of materials and improvements in their optoelectronic applications.

Carbon nanotube (CNT)-based hydrogels continue to present a persistent challenge of material comparability, as systems that appear equivalent frequently generate different mechanical, electrical, and biological responses. Although experimental variability is frequently cited as the primary explanation, many discrepancies arise from comparing systems whose nanotubes differ structurally in ways that are rarely documented. Diameter distribution, defect density, residual catalyst content, and surface chemistry directly influence CNT dispersion, network integration, and interactions in hydrated polymer matrices. When these parameters are insufficiently reported, formulations that appear comparable may represent materially distinct systems. In this review, the CNT–hydrogel literature is reconsidered from the perspective of material comparability. Rather than focusing only on whether reported results agree across studies, this review evaluates whether sufficient structural and processing information is available to determine if the systems being compared are materially equivalent. Selected publications were analyzed using a reporting-based descriptor framework encompassing nanotube origin, structural characterization, dispersion, microstructure, transport behavior, and biological relationships. A consistent pattern emerges: reproducibility becomes more interpretable when nanotube identity and processing history are documented with sufficient resolution. This enables meaningful cross-study comparison without requiring strict protocol standardization.

This work presents the effect of synthesis time on morphology and its influence on the optical properties of microwave-assisted carbon nanospheres. To analyze the correlation between the synthesis time and the growth in size of the nanospheres, the morphology of the nanostructures was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Their optical properties were analyzed by UV-Vis spectrophotometry, and the Tauc method was used to estimate the optical band gap. The results reveal that the time variation in the synthesis does have a significant influence on the size, shape, and amount of sample obtained. The optical properties presented slight modifications. With these results, we can provide an easy reproducibility of simple and inexpensive methods to optimize the growth of carbonbased nanoparticles, which can bring advances in the synthesis of materials and improvements in their optoelectronic applications.

The emergence of superhydrophobic antibacterial materials represents a promising approach to maintaining surface cleanliness and hygiene by effectively preventing bacterial adhesion. This research outlines the synthesis of a superhydrophobic coating with anti-adhesion and bacteriostatic properties, utilizing silica nanoparticles (SiO₂ NPs) modified with 1H,1H,2H,2H-Perfluorodecyltriethoxysilane (PFDTES). Transmission electron microscopy (TEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy were conducted to analyze the coating’s morphology and surface characteristics. The coating was applied to glass substrates using the spray coating method, and the number of layers was varied to evaluate its antibacterial and bacteriostatic properties. These properties were measured using turbidimetry and inhibition halo techniques. Additionally, the durability of the coatings was assessed by exposing them to outdoor conditions for 35 days. This study aimed to evaluate the antibacterial and bacteriostatic capacities of the superhydrophobic coating, along with its resistance to outdoor weathering. The results indicate that a superhydrophobic coating with a contact angle ≥ 150° and a sliding angle ≤ 10° was successfully synthesized using SiO₂ NPs smaller than 10 nm, modified with PFDTES. The coating demonstrated an ability to inhibit bacterial growth by preventing the adhesion of bacteria such as Escherichia coli and Staphylococcus aureus. Furthermore, the number of coating layers significantly influenced its bacteriostatic efficacy. The coating also exhibited strong durability under outdoor conditions. These findings highlight the potential application of superhydrophobic coatings for the prevention of bacterial adhesion and growth in environments where such contamination poses risks.

The emergence of superhydrophobicity-based antibacterial materials represents a promising approach to upholding surface cleanliness and hygiene, effectively preventing bacterial adhesion. This research describes the synthesis of a superhydrophobic coating with antibacterial and bacteriostatic properties using silica nanoparticles (SiO2 NPs) modified with 1H,1H,2H,2H-Perfluorodecyltriethoxysilane (PFDTES). TEM, XRD, EDS, SEM, and FTIR analyses were conducted to study its morphology and surface characterization. Additionally, the coating was applied on glass substrates using the spray coating method, varying the number of layers to evaluate antibacterial and bacteriostatic properties through turbidimetry and inhibition halo measurement techniques. The durability of the coatings was also assessed by exposing them to outdoor conditions for 35 days. This study aimed to evaluate the antibacterial capacity of the superhydrophobic coating and its weather resistance. The results demonstrate that a superhydrophobic coating with a contact angle ≥150° and a sliding angle ≤10° was successfully synthesized using SiO2 NPs smaller than 10 nm modified with PFDTES. The coating exhibited the ability to inhibit bacterial growth by preventing the adhesion of bacteria such as Escherichia coli and Staphylococcus aureus; moreover, the number of layers correlated with enhanced antibacterial properties. The coating also showed good durability under outdoor conditions. These results support the potential application of superhydrophobic coatings to prevent these bacteria from adhering and growing in areas where they can be harmful.

This work describes a liquid allantoin-enriched pectin hydrogel with hydrophilic behavior that is supported by the presence of functional groups related to healing efficacy. A topical study shows the effect of the hydrogel application on surgically induced skin wound healing in a rat model. Contact angle measurements confirm hydrophilic behavior (11.37°), while Fourier-transform infrared spectroscopy indicates the presence of functional groups related to the healing effectiveness (carboxylic acid and amine groups). Allantoin is distributed on the surface and inside the amorphous pectin hydrogel surrounded by a heterogeneous distribution of pores. This promotes wound drying with better interaction between the hydrogel and cells involved in the wound healing process. An experimental study with female Wistar rats indicates that the hydrogel improves wound contraction, reducing around 71.43% of the total healing time and reaching total wound closure in 15 days.

Bacterial biofilm that formed when the Ti6Al4 V alloy was exposed to Escherichia coli, was monitored over 48 h by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PP) to estimate the rate of corrosion and the influence of the bacteria on this process. High-resolution scanning electron microscopy was used to examine bacterial growth, colonisation and the process of biofilm formation. Our results highlighted several critical points regarding the impact of E. coli and its use as a model for monitoring biofilm formation and the biocorrosion of this alloy. Impedance spectra revealed the formation of a compact passive film after 48-hour exposure to an aging culture of E. coli in chloride media. The formation of the biofilm influenced the resistance to corrosion. Biofilm impedance parameters that emerged over time corresponded directly to the properties of a typical exponential bacterial growth curve determined by ultraviolet-visible light spectroscopy.