Ceramic filters are an effective, low-cost solution for water potabilization, particularly in rural communities. The integration of 3D printing has advanced this traditional approach by enabling precise control over design parameters that govern filtration efficiency. Gyroid-type ceramic scaffolds for water treatment were fabricated by clay-based extrusion 3D printing. Two ceramic pastes (ECP 1 and ECP 2) containing kaolin, attapulgite, alumina, and feldspar were formulated; ECP 2 incorporated 10 wt% activated carbon as a sacrificial porogenic phase. Rheological characterization using rotational rheometry and Bingham model fitting identified 40 wt% water as optimal for extrusion. Sintering at 1100°C produced interconnected open-pore networks in ECP 2 (apparent porosity: 23.6%; water absorption: 11.8%). Scaffolds were functionalized with silver nanoparticles (AgNPs) and ethanolic extracts of Moringa oleifera. AgNPs exhibited surface plasmon resonance at 422 nm; silver leaching was 0.00282 ppm (WHO limit: 0.1 ppm). Ethanolic extract E2 (80% v/v) showed significantly lower MIC (0.175 g/mL) than E1 (0.35 g/mL; p < 0.05) and bactericidal activity (MBC/MIC ⩽ 4.0). Functionalized scaffolds (EG) reduced biofilm formation by 80%-95% versus controls at 24 h (MTT assay) and maintained cellular compatibility above the 80% ISO 10993-5 threshold at 7 days. This combination of properties positions them as a highly promising alternative for advanced ceramic water filters.

Ceramic filters are an effective, low-cost solution for water potabilization, particularly in rural communities. The integration of 3D printing has advanced this traditional approach by enabling precise control over design parameters that govern filtration efficiency. Gyroid-type ceramic scaffolds for water treatment were fabricated by clay-based extrusion 3D printing. Two ceramic pastes (ECP 1 and ECP 2) containing kaolin, attapulgite, alumina, and feldspar were formulated; ECP 2 incorporated 10 wt% activated carbon as a sacrificial porogenic phase. Rheological characterization using rotational rheometry and Bingham model fitting identified 40 wt% water as optimal for extrusion. Sintering at 1100°C produced interconnected open-pore networks in ECP 2 (apparent porosity: 23.6%; water absorption: 11.8%). Scaffolds were functionalized with silver nanoparticles (AgNPs) and ethanolic extracts of Moringa oleifera . AgNPs exhibited surface plasmon resonance at 422 nm; silver leaching was 0.00282 ppm (WHO limit: 0.1 ppm). Ethanolic extract E2 (80% v/v) showed significantly lower MIC (0.175 g/mL) than E1 (0.35 g/mL; p < 0.05) and bactericidal activity (MBC/MIC ⩽ 4.0). Functionalized scaffolds (EG) reduced biofilm formation by 80%–95% versus controls at 24 h (MTT assay) and maintained cellular compatibility above the 80% ISO 10993-5 threshold at 7 days. This combination of properties positions them as a highly promising alternative for advanced ceramic water filters.

This study investigates the effect of substituting cobalt with manganese on the magnetic and optical properties of cobalt ferrite inorganic pigments synthesised by solution combustion. X‐ray diffraction analysis confirms the formation of a substitutional solid solution with manganese replacing cobalt, associated with a shift in diffraction peaks to lower angles due to the larger ionic radius of manganese. As the manganese concentration increases ( x = 0 to x = 0.6), lattice parameters and unit cell volumes increase, except at x = 0.5, which could be attributed to changes in cation distribution and lattice micro‐strain. Raman spectroscopy shows shifts in the vibrational modes of metal–oxygen bonds, influenced by differences in atomic masses and bond strength constants between manganese and cobalt. Magnetic measurements indicate a decrease in coercive field, saturation magnetisation and remanence with increasing manganese content, due to weaker super‐exchange interactions. Diffuse reflectance spectroscopy reveals low reflectance in the visible range due to electronic transitions in the metal ions. The substitution of manganese increases the band gap from 2.1 to 2.6 eV between x = 0.0 and x = 0.5, then decreases to 2.4 eV at x = 0.6. Colorimetric analysis shows significant variations in CIELab colorimetric coordinates, with lightness, chroma and hue changing with manganese content. Paints derived from these pigments, applied to cement, plaster and wood substrates, exhibit varied optical properties, demonstrating the influence of manganese on the optical characteristics of the pigments.

Inorganic pigments are widely used in various industries, including ceramics and paints. CoAl2O4 is a highly stable pigment, but its industrial synthesis requires high temperatures, resulting in long synthesis times and high costs. Alternative synthesis routes have been proposed, but they are often expensive and require multiple thermal treatment stages. Solution combustion synthesis shows promise in reducing costs and synthesis time, but optimization is required so that synthesis is achieved in one step. In this work, we studied the problem of synthesizing the inorganic pigment CoAl2O4 using a single-step solution combustion synthesis. Therefore, the aim was to investigate the influence of different fuels: urea and citrulline, and the addition of an extra oxidizing agent, ammonium nitrate (A.N.), on the combustion temperature and the resulting structure, morphology, and colour of the pigment. The addition of A.N. resulted in a significant increase in the combustion temperature and the formation of crystalline CoAl2O4. The color coordinates for the powder following combustion, with the inclusion of 2 g of ammonium nitrate (A.N.) in the fuel mixture at an optimized O/F ratio of 0.5, were determined as follows: L* = 58.23, a* = -8.27, b* = -30.25, C*ab = -31.33, and h*ab = 263 degrees, indicative of a blue hue. These results show that inorganic pigments could be used in ceramic decoration and acrylic paint. These findings are important for the development of new and efficient methods for synthesizing inorganic pigments with desirable properties for various applications.

This study focuses on designing and evaluating scaffolds with essential properties for bone regeneration, such as biocompatibility, macroporous geometry, mechanical strength, and magnetic responsiveness. The scaffolds are made using 3D printing with acrylic resin and iron oxides synthesized through solution combustion. Utilizing triply periodic minimal surfaces (TPMS) geometry and mask stereolithography (MSLA) printing, the scaffolds achieve precise geometrical features. The mechanical properties are enhanced through resin curing, and magnetite particles from synthesized nanoparticles and alluvial magnetite are added for magnetic properties. The scaffolds show a balance between stiffness, porosity, and magnetic responsiveness, with maximum compression strength between 4.8 and 9.2 MPa and Young's modulus between 58 and 174 MPa. Magnetic properties such as magnetic coercivity, remanence, and saturation are measured, with the best results from scaffolds containing synthetic iron oxides at 1% weight. The viscosity of the mixtures used for printing is between 350 and 380 mPas, and contact angles between 90° and 110° are achieved. Biocompatibility tests indicate the potential for clinical trials, though further research is needed to understand the impact of magnetic properties on cellular interactions and optimize scaffold design for specific applications. This integrated approach offers a promising avenue for the development of advanced materials capable of promoting enhanced bone regeneration.

The effect of sodium chloride (NaCl) on the magnetism of nanopowders of the spinel ferrite (MgFe2O4) produced using a salt-assisted solution combustion synthesis was investigated. X-ray diffraction (XRD) analysis was conducted to evaluate crystalline structure and phase composition of the synthesized materials. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) was used to evaluate the particle size and morphology. Magnetic behavior was analyzed by measuring and analyzing the respective hysteresis loops using a vibrating sample magnetometer (VSM). The characterization showed that the presence of NaCl affects the phase composition, size, and dispersion of the nanoparticles, as well as their magnetic behavior. The theoretical size of the nanoparticles was calculated using the Scherrer equation, obtaining sizes of about 21.07 nm for the nanoparticles without salt, 5.90 nm for the sample salt content of 1.7 mol and 6.48 nm—for 3.4 mol. The synthesized nanoparticles showed a drastic decrease in coercivity field, remanence, and saturation with increasing salt content. Therefore, the salt content is a crucial parameter in controlling the morphology and magnetic properties of the nanoparticles obtained by the solution combustion route.

Although several works have proposed modeling the low-carbon steel lattice parameters considering their carbon content, no detailed information about the crystalline structure has been reported. Herein, the crystal structure of the polycrystalline martensitic steel with carbon content of 0.15% has been refined, giving details about the sites and occupancies for the iron and chromium atoms. The body-centered tetragonal crystal system with space group I 4/mmm was considered for the refinement. The obtained results show that the refined occupancies for Fe and Cr (around 0.83 and 0.17, respectively) are close to the values reported in the technical references for this kind of steel. The final structure yields a well-adjusted refinement, with R wp = 8.49%, gof = 1.70, and R Bragg = 3.17%.

In this study, α-Fe 2 O 3 was synthesized by solution combustion method using 6-aminohexanoic acid (AH) as a fuel and with different oxidizer-to-fuel ratios (Φ) of 0.6, 0.8, 1.0, 1.2, and 1.4. The as-prepared powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy (IR), and UV–Vis spectroscopy. The results showed that the Φ ratio played a crucial role in determining the crystallinity and purity of the powders of α-Fe 2 O 3 . The α-Fe 2 O 3 powder synthesized at an Φ ratio of 0.6 exhibited phase purity of hematite. This study demonstrates the importance of controlling the Φ ratio in the synthesis of α-Fe 2 O 3 which could be used as an inorganic pigment in paints.

Avocado is highly susceptible to postharvest diseases and rapid ripening, making it challenging to maintain its quality and shelf life. One potential solution is the use of nanoparticles that can act as both antimicrobial agents and ethylene inhibitors. In this study, we synthesized Ag-doped TiO2 nanoparticles through a solution combustion method and subjected them to various characterization techniques, including X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. These nanoparticles were then tested for their effectiveness in combating common avocado pathogens and their ability to inhibit ethylene production. To apply our findings practically, we treated Hass avocado fruits in the postharvest stage with a suspension of Ag-doped TiO2 nanoparticles and stored them under controlled conditions to simulate the ripening process. The Ag-doped TiO2 nanoparticles formed agglomerates within the nanometric range and exhibited oxidation-reduction characteristics, effectively inhibiting ethylene production and degrading Rhodamine-B dye. Moreover, these nanoparticles displayed robust antimicrobial activity, significantly suppressing the growth of Colletotrichum gloeosporioides sensu lato pathogens. Treated fruits in the postharvest phase showed reduced microbial growth, decreased incidence of anthracnose, stem and root diseases, and an extended shelf life compared to the control group, due to ethylene inhibition. Ag-doped TiO2 nanoparticles, with their dual capabilities of antimicrobial activity and ethylene inhibition, show promise in improving postharvest management of Hass avocados. They have the potential to enhance fruit quality, reduce postharvest losses, and improve marketability. Further research and field trials are essential to fully explore the practical applications of these nanoparticles in commercial avocado production and distribution.

Calcium phosphates are materials of wide interest in the medical and agricultural industries. Advanced in the standardization of protocols to obtain them by combustion in solution in a single step is highly desirable. This is particularly so for the alpha-tricalcium phosphate (α-TCP) phase, widely used in the development of bone cement. In this research, citrulline was used as a fuel for the first time in the one-step synthesis of calcium phosphates, and the effect of adding 0–15 g of ammonium nitrate (AN) as an extra oxidizer agent was studied, allowing the temperature of the reaction to increase from 648 to 950°C. The temperature was measured using low-cost equipment with infrared and type-K thermocouple and contrasted with the estimated theoretical values of adiabatic flame temperature. X-ray diffraction analysis showed the formation of a mixture of α-TCP and hydroxyapatite phases at the lowest combustion temperature, corresponding to 0 g of AN. When the amount of AN was increased, the XRD showed that α-TCP was obtained as a metastable phase, while the amount of hydroxyapatite decreased considerably. At higher combustion temperatures, the crystallite size estimated by Scherrer equation, in turn, increased to a value of 51.61 nm. The SEM images showed the presence of necks between particles in the powders that coincide with the estimation of high reaction temperatures.

Biocompatible ceramic scaffolds offer a promising approach to address the challenges in bone reconstruction. Wollastonite, well-known for its exceptional biocompatibility, has attracted significant attention in orthopedics and craniofacial fields. However, the antimicrobial properties of wollastonite have contradictory findings, necessitating further research to enhance its antibacterial characteristics. This study aimed to explore a new approach to improve in vitro biological response in terms of antimicrobial activity and cell proliferation by taking advantage of additive manufacturing for the development of scaffolds with complex geometries by 3D printing using propolis-modified wollastonite. The scaffolds were designed with a TPMS (Triply Periodic Minimal Surface) gyroid geometric shape and 3D printed prior to impregnation with propolis extract. The paste formulation was characterized by rheometric measurements, and the presence of propolis was confirmed by FTIR spectroscopy. The scaffolds were comprehensively assessed for their mechanical strength. The biological characterization involved evaluating the antimicrobial effects against Staphylococcus aureus and Staphylococcus epidermidis, employing Minimum Inhibitory Concentration (MIC), Zone of Inhibition (ZOI), and biofilm formation assays. Additionally, SaOs-2 cultures were used to study cell proliferation (Alamar blue assay), and potential osteogenic was tested (von Kossa, Alizarin Red, and ALP stainings) at different time points. Propolis impregnation did not compromise the mechanical properties of the scaffolds, which exhibited values comparable to human trabecular bone. Propolis incorporation conferred antibacterial activity against both Staphylococcus aureus and Staphylococcus epidermidis. The implementation of TPMS gyroid geometry in the scaffold design demonstrated favorable cell proliferation with increased metabolic activity and osteogenic potential after 21 days of cell cultures.

The avocado cv. Hass is one of the most dynamic fruits in the world and is of particular significance in tropical areas, where climate variability phenomena have a high impact on productivity and sustainability. Nanotechnology-based tools could be an alternative to mitigate and/or adapt plants to these phenomena. Our approach was based on identifying changes in temperature and precipitation associated with climate variability in avocado areas in Colombia and proposing mitigation strategies based on the use of nanotechnology. This study had two objectives: (i) to identify variations in temperature and precipitation in avocado-producing areas in Colombia and (ii) to evaluate the effect of calcium phosphate nanoparticles (nano CP) as an alternative to reduce stress in avocados under simulate climatic variability condition. Climatic clusters were determined based on the spatial K-means method and with the climatic temporal series data (1981-2020), a time series analysis we carried out. Later changes in each cluster were simulated in growth chambers, evaluating physiological and developmental responses in avocado seedlings subjected to nanoCaP after adjusting the application form and dose. XRD diffraction shows that the calcium phosphate phases obtained by solution combustion correspond to a mixture of hydroxyapatite and witocklite nanoparticles with irregular morphologies and particle sizes of 100 nm. Three clusters explained similar to 90% of the climate variation, with increases and decreases in temperature and precipitation in the range of 1-1.4 degrees C and 4.1-7.3% respectively. The best-fitted time series models were of stationary autoregressive integrated moving averages (SARIMA). The avocado seedlings had differential responses (P<0.05) depending on the clusters, with a decrease in physiological behavior and development between 10 and 35%. Additionally, the nanoCaP reduced the climatic stress (P< 0.05) in a range between 10 and 22.5%. This study identified the negative effect of climate variability on avocado seedlings and how nanoCaP can mitigate these phenomena.

This work aims to determine the most suitable synthesis route using calcium phosphate ceramic pastes with Mg to generate scaffolds with antimicrobial activity against Candida albicans and Streptococcus mutans from ceramic powders obtained by sol-gel (SGM) and self-combustion (SCM) routes. Calcium phosphates in SGM processes present a mixture of several types of crystalline phases, whereas SCM leads to a single & beta;-TCP phase. The in vitro antimicrobial activity study showed that CP-C/Mg by SCM had a better effect than CP-S by SGM against C. albicans. For S. mutans, no inhibitory effect was found. In addition, the co-culture of these two species showed an inhibitory effect on the evaluated materials. These results formulated a ceramic paste based on the & beta;-TCP/Mg/ bioglass system by the design of experiments to obtain 3D-printed scaffolds. These ceramic materials show promise as devices for the regeneration of dental tissues.

The increase in critical bone diseases and defects in the world's population increases the need for bone substitutes to restore form and function. Organic and inorganic scaffolds with antibacterial properties could provide advantages for bone regeneration. In this study, we obtained scaffolds of polycaprolactone (PCL) charged with calcium phosphates nanoparticles and impregnated with extracts of Colombian plants as an alternative for potential bone regeneration. Calcium phosphate nanoparticles were obtained via auto-combustion synthesis. The nanoparticles were incorporated into the PCL with a chemical dissolution-disperse process. The composite obtained was used to produce a filament to print Triply Periodic Minimal Surface (TPMS) based scaffolds. Such geometry facilitates cellular growth thanks to its interconnected porosity. The scaffolds were impregnated with extracts of Justicia cf colorifera (Acanthaceae), and Billia rosea (Sapindaceae) due to their ancestral medical applications. A physical and biological characterization was conducted. The process to print scaffolds with an enhanced geometry to facilitate the flux of biological fluids was successful. The scaffolds loaded with B. rosea showed strong antibacterial behavior, suggesting the presence of reported terpenoids with antibacterial properties. The approach used in this study evidenced promising prospects for bone defect repair.

Several diseases and injuries cause irreversible damage to bone tissues, which may require partial or total regeneration or replacement. Tissue engineering suggests developing substitutes that may contribute to the repair or regeneration process by using three-dimensional lattices (scaffolds) to create functional bone tissues. Herein, scaffolds comprising polylactic acid and wollastonite particles enriched with propolis extracts from the Arauca region of Colombia were developed as gyroid triply periodic minimal surfaces using fused deposition modeling. The propolis extracts exhibited antibacterial activity against Staphylococcus aureus (ATCC 25175) and Staphylococcus epidermidis (ATCC 12228), which cause osteomyelitis. The scaffolds were characterized using scanning electron microscopy, Fourier-transform infrared spectroscopy, differential scanning calorimetry, contact angle, swelling, and degradation. Their mechanical properties were assessed using static and dynamic tests. Cell viability/proliferation assay was conducted using hDP-MSC cultures, while their bactericidal properties against monospecies cultures (S. aureus and S. epidermidis) and cocultures were evaluated. The wollastonite particles did not affect the physical, mechanical, or thermal properties of the scaffolds. The contact angle results showed that there were no substantial differences in the hydrophobicity between scaffolds with and without particles. Scaffolds containing wollastonite particles suffered less degradation than those produced using PLA alone. A representative result of the cyclic tests at Fmax = 450 N showed that the maximum strain reached after 8000 cycles is well below the yield strain (i.e., <7.5%), thereby indicating that even under these stringent conditions, these scaffolds will be able to work properly. The scaffolds impregnated with propolis showed a lower % of cell viability using hDP-MSCs on the 3rd day, but these values increased on the 7th day. These scaffolds exhibited antibacterial activity against the monospecies cultures of S. aureus and S. epidermidis and their cocultures. The samples without propolis loads did not show inhibition halos, whereas those loaded with EEP exhibited halos of 17.42 ± 0.2 mm against S. aureus and 12.9 ± 0.5 mm against S. epidermidis. These results made the scaffolds possible bone substitutes that exert control over species with a proliferative capacity for the biofilm-formation processes required for typical severe infectious processes.

Nanocomposites of nickel oxide/yttria-stabilized zirconia (NiO/YSZ) particles were synthesized via solution combustion synthesis using glycine and urea as fuels in one step. The powders were characterized by X-ray diffraction (XRD) analysis, where the synthesis with urea showed the formation of the NiO/YSZ composite, while the presence of Ni with NiO/YSZ were observed when the glycine was used. The morphology of the as-prepared powders and the presence of Ni were corroborated by field emission scanning electron microscopy and energy dispersive X-ray spectroscopy (FE-SEM; EDX). The powders showed catalytic behavior which was evidenced by H2-TPR measurements. These materials could be used for the fabrication of Ni/YSZ anode for fuel cells.

Spinel ferrites are promising candidates for various applications as transformers, transducers, inductors in the electronic field, sensors, biosensors and hyperthermia agents in the biomedical field. Combustion synthesis, as a method for obtaining ferrites, is gaining attention. However, most fuels generate high ignition temperatures, which lead to larger (micrometric) crystallites or even render combustion synthesis unfeasible in a single step. Spinel cobalt ferrite (CoFe2O4) has unique features that facilitate tuning the spinel structure based on modifications in the synthesis parameters. In this study, CoFe2O4 was synthesised via gel combustion using tris (hydroxymethyl)aminomethane (tris) as an alternative fuel. The effect of the oxidizer-to-fuel molar ratio (psi) on their formation and structural, optical, and magnetic properties were evaluated. Gels were prepared from metal nitrates and tris at psi values of 0.6, 0.8, 1.0, 1.2, and 1.4. Thermal analysis of the ignition temperature was found to be dependent on psi. The adiabatic flame temperatures were estimated using thermodynamic calculations, as 2688.36 K when psi = 0.6, and 1017.56 K when psi = 1.4, which indicates that the temperatures would be sufficient to form the phase in one step without additional thermal treatment. X-ray diffraction confirmed the formation of CoFe2O4 as a single-phase for all psi values. Raman and Fourier transform infrared spectroscopy confirmed the formation of CoFe2O4 for all psi values investigated. The low bandgap values (0.92-1.36 eV) suggest several promising applications in photoactivated materials. The magnetic properties of the as-prepared powders measured by a vibrating sample magnetometer revealed saturation magnetisation values, Ms, and coercivity field, Hc, and remanence magnetisation were dependant on psi. These results show that tris can be used as a fuel to synthesise spinel ferrites via one-step gel combustion with excellent properties for several applications.

Calcium phosphates are biomaterials widely used in bone tissue engineering. In recent years, the alternative of obtaining these materials with antimicrobial properties, has been explored due to the multiple advantages that this would imply in the design of devices or implants that prevent the failure of these associated with bacterial colonization. The goal of the present work was obtaining gold nanoparticles supported on biphasic calcium phosphates (BCPs) with high crystallinity by one-step solution combustion technique, and with antimicrobial response, a fact that can significantly reduce the production cost of these materials. X-ray diffractograms (XRD) showed that prepared powders have high crystallinity owing to high temperatures during the combustion reaction, also Rietveld refinement showed that the inclusion of gold nanoparticles (AuNPs) influenced the phases’ ratio obtained. Furthermore, scanning electron microscopy (SEM) showed agglomeration of particles with morphologies with shape tending to be equigranular, while the presence of AuNPs was corroborated by transmission electron microscopy (TEM). All samples that were obtained in a single step, by solution combustion, showed antimicrobial behavior validated through the inhibition halos, whereas particles subjected to thermal treatment lost their antimicrobial response.