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La nanotecnología agrícola y ambiental tiene cientos de aplicaciones para solucionar problemas que aquejan a la sociedad día con día. No obstante, los países de América Latina han participado relativamente poco en estos avances tecnológicos, al compararlos con sus contrapartes de América del Norte, Europa o Asia. Dado lo anterior, es importante destacar que países como México, Chile y Brasil tienen avances nanotecnológicos significativos y han logrado la formación de grupos de especialistas consolidados, a pesar de las limitaciones económicas y de acceso a equipo científico que aqueja a estas naciones. En consecuencia y con base en las múltiples aplicaciones potenciales, algunas ya en comercialización, es necesario que el Estado, la industria y la comunidad científica fortalezcan e impulsen la innovación, el equipamiento y la formación de recursos humanos, así como una adecuada inversión en nanotecnología agrícola y ambiental. Asimismo, se deben considerar aspectos de normalización y regulación, tanto como estudios in silico e in vivo (en laboratorio, invernadero y campo) que valoren y evidencien los efectos nulos, secundarios o tóxicos de los nanomateriales sobre los organismos vivos y los ecosistemas.

A series of mixed Al2O3-Ga2O3 oxides were prepared with different Ga2O3 content (labeled as AlGa-x; where x is the wt % of Ga2O3) by precipitation method. The oxides were then used as supports of palladium (2 wt %) catalysts (labeled as Pd/AlGa-x). Both series of samples, AlGa-x and Pd/AlGa-x were characterized by several techniques such as Raman spectroscopy, XPS, XRD, SEM, and HRTEM, and were tested in the 2-propanol dehydration reaction. The steady-state conversions displayed by the Pd/AlGa-x series was almost twice as that obtained for the AlGa-x series in all the range of tested temperatures. It was worth noting that the presence of palladium changed the yield observed for the AlGa-x series mainly at low temperatures. While at high temperatures the Lewis acidity provided by the well dispersed Pd nanoparticles increased the activity considerably and improved the propylene production. A balance between the dispersion of palladium and the surface acidity, both related to the Ga2O3 content was responsible for the observed catalytic behavior.

In the present work, a type of zirconium metal organic framework known as UiO-66 (reported by researchers from the University of Oslo, for which it is called acronym) was used to adsorb ibuprofen and release it in a medium simulating the blood pH. The bioviability and low toxicity of the UiO-66 are the characteristics by which this nanomaterial was chosen to transport a drug. This project implemented a methodology for the synthesis of UiO-66 at room temperature; it was also achieved to adapt the techniques of in vitro release of drugs reported in the literature, to the simulated release of ibuprofen using the UiO-66 framework. The aim of the in vitro simulation was to determine the efficiency with which this material transports and releases ibuprofen to the blood. Therefore, the simulation conditions considered a physiological temperature of 37 ° C and a release medium (buffer solution of phosphates) with pH similar to the blood. The results show that the release was carried out gradually during the first 24 h. In addition, regardless of the initial concentration, the amount of ibuprofen released was the same.

Synthesis of a new HKUST-1 composite based on single-walled carbon nanotubes (SWCNTs) was successfully achieved (SWCNT@HKUST-1). SWCNTs were used as templates to grow rod-like HKUST-1 crystals over the surface of the nanotubes. N2 adsorption properties showed an increment on the surface area and pore volume for the SWCNT@HKUST-1 composite. Furthermore, the CO2 capture increased, from 7.92 to 8.75 mmol g-1 at 196 K up to 100 kPa, for the SWCNT@HKUST-1 composite. This enhancement was directly associated with the increase of the surface area of the composite. Additionally, an increase in the CO2 heat of adsorption was estimated, from 30 to 39.1 kJ mol-1 for the SWCNT@HKUST-1 composite. In situ Raman experiments corroborated the favored CO2 adsorption for the composite and provided an insight into the augmented hydrophobicity of the SWCNT@HKUST-1. Ethanol adsorption isotherms corroborated an increase in the hydrophobicity of the material upon the incorporation of carbon nanotubes.

This paper presents the synthesis of the metal-organic structure of terbium Tb2(BDC)3 (BDC: 1,4-benzendicarboxylic acid) obtained by stirring at room temperature (SRT) and by means of the microwave-assisted synthesis method (MW) at 150 °C during 15 min. A comparison was made between the physicochemical properties of the MOF obtained by each of the methods as they were characterized by powder X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR), observing crystalline materials with crystal size 66.42 and 26.57 nm for SRT and MW, respectively. The luminescent properties were determined by photoluminescent spectroscopy (FL) and finally the morphology presented by MW synthesis.

In this work we have evaluated the fungicide effects causing the growth inhibition of Aspergillus niger, Fusarium solani and Penicillium chrysogenum using three metal–organic framework materials (MOFs): HKUST-1 (three-dimensional structure), HKUST-1NP doped with copper oxide nanoparticles (CuO-NPs) and sterilized HKUST-1 (which generated a one-dimensional Cu(BTC)(OH)(H2O)-type structure). The materials were synthesized by stirring at room temperature under atmospheric pressure, and were compared to commercial CuO-NPs to evaluate the toxic effects using a radial growth (inhibition halo) technique. The MOFs were thoroughly dispersed in culture media, and the fungi were cultured on potato dextrose agar plates containing different concentrations of the tested materials. A thorough characterization of the studied materials was carried out through PXRD, FTIR, N2 adsorption, TGA and SEM measurements in order to determine the physicochemical properties. For A. niger, none of the tested materials inhibited its growth; it hence proved to be resistant, due to its ability to leach copper from the compounds. In the case of F. solani, concentrations between 750 to 1000 ppm caused 100% inhibition of growth. For P. chrysogenum, it was observed that increasing the concentration of MOFs up to 1000 ppm caused a concomitant increase in inhibition. This work represents the first report underlining the possible use of MOFs as fungicides, and the results have shown growth inhibition capability in some species, opening up possible new applications in this field.

The highly porous metal–organic framework based on copper-benzenetricarboxylate (HKUST-1, Cu3(BTC)2, MOF-199) is used for a loading study of basic fuchsin (BF, neutral charge, ϕ = 12.40 A molecular diameter, 50 ppm solution), crystal violet (CV, cationic charge, ϕ = 15.10 A, 50 ppm solution) and Eriochrome Black T (EBT, anionic charge, ϕ = 15.50 A, 80 ppm solution), as chosen molecular probes for physicochemical analysis and interactions. Characterization is carried out using XRD, FTIR, SEM, and TGA, and UV-Vis is used to determine the differential concentration of loaded dye in the MOF. The adsorption process is evaluated by three incorporation methodologies: post-synthesis (PS) and one-pot in organic (OPO) or metallic (OPM) solution. XRD cell parameters reveal the general compactness of the net through ionic (CV and EBT), dipolar (BF, CV and EBT) and van der Waals (BF, CV and EBT) dye–MOF interactions. Enhanced compactness is observed for CV due to its cationic nature and medium size; the effect is not as strong in EBT, which is anionic in nature but bigger in size, and the least compactness is observed for BF, which lacks ionic interaction with the net. The samples have crystal sizes between 34 and 57 nm, which indicate the generation of nanomaterials. The employed procedures yield crystallite size in the following order: PS < OPO < OPM. The (%) adsorption of all the dyes is above 86.93%, which is observed for the EBT-PS sample as the lowest and 99.42% for BF-PS as the highest, which evidences the high displacement of equilibrium in the studied systems to the Cu3(BTC)2·dye occluded state. Thus, MOFs can be suggested as potential adsorbents/loaders of BF/CV/EBT dyes for composite material generation as well as MOF·molecule interaction studies because of their high loading ability and obtained stability as well as facile synthesis.

In the present work luminescent metal–organic frameworks consisting of terbium ions as the metallic center and 1,4 benzene-dicarboxylic acid (BDC), benzene-tricarboxylic (BTC) acid and 1,3 thiophane-dicarboxylic acid (TDC), as the organic ligands, are synthesized by the microwave assisted solvothermal method at a relatively short time. The samples are studied before and after a thermal annealing process at 400°C. The structural and chemical analysis indicate the formation of nanocrystals of about 8.8 nm, 5.0 nm and 127 nm for BDC, BTC and TDC samples, respectively. All the samples show carbon and oxygen in excess attributed probably to remnants of the N,N-Dimetilformamide used as solvent during the synthesis or to diffused particles from the atmosphere. The luminescent analysis shows a high quantum yield value for the BDC framework, 99.6%, after the annealing process, attributed to an antenna effect; whereas both the BTC and TDC samples show a higher quantum yield before annealing; 64.1% and 13.3%, respectively. The luminescence decay time is also computed in the samples resulting between 1 and 1.5 ms for both BDC and BTC samples, whereas for the TDC sample the decay time was about 0.2 ms. A noticeable daylight visible PL emission is observed in all samples.

A high surface area binary Al2O3-Ga2O3 oxide (AlGa) (75% wt%/25 wt%) was prepared by a single-stage precipitation method, and then used as support for noble metal catalysts (3 wt% nominal metal content). Effect of noble metals (Os, Pd, Rh, and Pt) on the surface distribution and the type of species formed were investigated by SBET, XRD, SEM-EDS mapping, HRTEM, DRIFT-CO and XPS techniques and tested in the Water-Gas Shift (WGS) reaction carried out in a fixed bed reactor at atmospheric pressure and temperature range 160–400 °C. The activity tests revealed that the reactivity of the catalyst followed the order: Pd/AlGa > Pt/AlGa > Rh/AlGa > Os/AlGa. The Pd and Pt-based catalysts presented the light-off reaction temperature at about 280 °C while the Os and Rh-based ones were activated at 300 °C and 325 °C, respectively. For the best Pd/AlGa catalyst, the DRIFTS spectra of chemisorbed CO revealed the presence of isolated peripheral or basal palladium species suggesting the importance of those species for the WGS reaction. For the Pt/AlGa catalyst, the combined EDS mapping and HRTEM studies indicated the highest dispersion of the metal phase among the catalysts studied. In this case, the absence of a correlation between the catalyst activity and metal dispersion suggests that factors other than metal dispersion control its catalytic performance.

The metal-organic framework (MOF) HKUST-1 was employed as an interaction matrix for fundamental loading studies of anthraquinone dyes. Chosen dyes were alizarin (A), alizarin S (AS), disperse blue 1 (B1), disperse blue 3 (B3), disperse blue 56 (B56) and purpurin (P). All materials were characterized by XRD, FTIR, TGA and SEM. Hence the interaction of dyes with the framework was characterized by theoretical-experimental differential analysis. One-pot loading strategy resulted in more efficient scavenging of dyes, and reached 100 % for B56 using 50 mg L-1 . SEM revealed important microstructural changes, the smaller crystals ranged 0.8-3 μm in size and almost all composite sizes were from this to higher values, reaching 70 μm, with varying shapes. Two composites were larger in size range (about 2500-1000 μm), and were shaped as rods, octahedrons and coffin lids. Indeed, the microstructure could be modulated depending on preparation conditions and type of loaded dye. For the higher loading series, N2 adsorption and XPS experiments were carried on to further evidence dye-MOF interactions. Ab initio prediction of structural properties for A@HKUST-1 and P@HKUST-1 were obtained by means of solid-state CRYSTAL14 code at the PBE0 level of theory. Computed findings evidenced two O→Cu coordinative bonds, one from O-ketone and the other from O-phenolate moiety as main interactions towards CuNET centers.

Agronanobiotechnology is a term that refers to the intersection of agronomy, nanotechnology, and biotechnology. Agronanobiotechnology is a discipline in which tools from nanotechnology are developed and applied to the study of agronomic and biological phenomena. The objective of this chapter is to present cutting-edge knowledge regarding agronanobiotechnology, which is aimed at preserving environmental health and improving the welfare of farmers while also increasing crop yields and the production of innocuous feed. Producers of innovative products in agronanobiotechnology are experiencing difficulties in bringing these products to market, because of their high production costs, which regularly are required in high volumes in the agricultural sector, while unclear technical benefits, legislative uncertainties, and negative public opinion are hampering the development of agronanobiotechnology; notwithstanding these difficulties, the possibilities offered by agronanobiotechnology in several agricultural applications are moving forward. Meanwhile, progress in legislation, nanoremediation, environmental monitoring, international safety regulation, and drug delivery techniques could improve the agricultural and livestock sector indirectly. For research and development in agronanobiotechnology to move forward, long-term in situ field trials are required, while social welfare must also be guaranteed in order to shape sustainable development.

Several international studies have shown that the performance of watering practices and irrigation equipment are still too low, while the water quality and availability are increasingly scarce worldwide. Consequently, there are reductions in crop yields and a waste of water resources. The objectives of this chapter are (1) discussing some bibliographic evidence regarding the availability of agronanobiotechnologies to improve the water quality and watering efficiency in agricultural irrigation systems and (2) describing some technological developments used in the design of cheap and eco-friendly filters with natural or engineering nanomaterials and organic wastes. It has been found that groundwater irrigation has grown rapidly over the past 50 years and now supplies over one-third of the world’s irrigated area. Water management emerged as a strategic resource, not only in many arid and semiarid countries, but also in humid climates, because of its capacity to support intensive land use and high-value agriculture. However, effective governance of watering water and the implementation cutting-edge technologies are critical and urgent challenges. It is required to critically examine the various approaches that different technologies have proposed for taking advantage sustainably about irrigation water and assessing their wider applicability for promoting its responsible use worldwide, while better water technologies and management are urgent and critical for productivity, equity, and sustainability.

The synthesis of engineered nanomaterials (ENMs) has increased in recent years because novel and unexpected properties and applications have been found to such a degree that hundreds of scientists have published concerns and evidence regarding the toxicology of ENMs. However, most of the reported findings have been inconsistent, so more research is needed, but also long-term in situ field trials are required, while the standardization of tests, chemical reagents, and methodologies must be strengthened and regulated in accordance with scientific advice or international organizations. This chapter discusses new findings published during the last 5 years regarding the advantages and disadvantages of ENMs, as well as findings obtained in our laboratories and greenhouse. We found that ENMs have favorable effects on some crops and biological systems. Consequently, ENMs have potential industrial applications in the agricultural sector, with biological, environmental, and ecological advantages. Nevertheless, the effects of ENMs depend on the kind of ENM, exposition period, concentration, substrate or soil type, kind and age of organisms, biotic and abiotic interactions, etc.; i.e., a specific test has to be carried out for each particular condition, and generalizations regarding the effects of ENMs should be avoided, otherwise human and environmental health—but also sustainable development—will be compromised.

In recent years, metal organic frameworks (MOF) have received considerable interest due to their physicochemical properties, such as structures’ flexibility, high surface area, tuna‐ ble pore size, and topologies, among others, which have lead to promising applications, particularly in the area of catalysis. In this chapter, we present the most important results of research conducted with MOF in catalytic applications; mainly in the design of its structure, synthesis, characterization, and possible limitations.

For the construction of the metal–organic framework [Cu3(BTC)2] (commonly known as MOF-199 or HKUST-1), three different synthesis strategies were employed: room temperature stirring (RT), solvothermal (ST) and ultrasonic assisted (US); which afforded the desired material in moderate yields. Several characterization techniques (XRD, FT–IR, SEM and TGA) showed that HKUST-1 was obtained in every method. However, there were found interesting differences in functionalization depending on the synthesis conditions which produced the same [Cu3(BTC)2] host net but with different coordinative and bulk molecular guests. By XRD pattern analysis, it was possible to identify characteristic peaks of Cu2O in the ST obtained material as secondary phase, showing that this methodology is quite harsh giving place to this product, although the [Cu3(BTC)2] complex was obtained in good yield. Regardless the energy source applied, in all three cases the desired [Cu3(BTC)2] MOF was obtained. In order to determine if the method of synthesis impacts directly on the electrochemical behavior of de material, applied cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) were investigated. The electrochemical results have shown that the resistance to the faradic process increases in the following order: Cu–MOFUS, Cu–MOFRT and Cu–MOFST. This behavior can be associated to the presence of Cu2O in Cu–MOFST. However, the synthesized MOF at room temperature showed a major content of copper, which could be electrochemically transformed, as well as purity, in comparison with those obtained by solvothermal and ultrasonic assisted methods.

This investigation is based on a combination of experimental tools completed by a computational approach to deeply characterize the unusual adsorption behavior of the flexible MIL-53(Fe) in the presence of short linear alkanes. In contrast to the aluminum or chromium analogues we previously reported, the iron MIL-53 solid, which initially exhibits a closed structure in the dry state, shows more complex adsorption isotherms with multisteps occurring at pressures that depend on the nature of the alkane. This behavior has been attributed to the existence of four discrete pore openings during the whole adsorption process. Molecular simulations coupled with in situ X-ray powder diffraction were able to uncover these various structural states.

The adsorption of C1 to C4 linear hydrocarbons in the flexible metal organic framework MIL-53(Cr) has been followed by adsorption manometry coupled with microcalorimetry and Synchrotron X-ray powder diffraction. This experimental investigation was completed by molecular modeling. In the case of methane, the solid remains rigid whatever the adsorbate amount. However for the C2-C4 series, an increasing flexibility of the structure is observed, which is ascribed first to a breathing of the material from a large pore to a narrow pore form followed by a further expansion at high pressure. The collected thermodynamic and structural information suggests that a minimum adsorption enthalpy of ca. 20 kJ mol (-1) in the initial large pore structure of MIL-53(Cr) is required to induce the structural transition "large to narrow pore". Further, the enthalpy of adsorption can be used to predict the pressure at which the structure reopens. Finally, the magnitude of the breathing can be related to the size of the probe molecule via the van der Waals volume. The above trends have been successfully verified in the case of water and carbon dioxide. This combined experimental and theoretical approach gives the first elements for the prediction of whether or not the MIL53 and similar flexible structures will respond to gas loading and what would be the pressure required and further the amplitude of the induced breathing.

La salud humana se enfrenta constantemente a nuevas amenazas ante las cuales es indispensable que los medicamentos actúen rápidamente. Por ello, en la actualidad se buscan nuevas formas de administración y liberación de fármacos utilizados en el combate de ciertas enfermedades. La implementación y desarrollo de nanomateriales para actuar como trasportadores y dosificadores se ha convertido en una línea de investigación a nivel mundial. En este contexto, se han probado diversos tipos de materiales como son: las nanopartículas poliméricas, los polímeros conjugados, los liposomas, las micelas, las dendritas, los nanotubos de carbono y las nanoesferas o nanocajas (poliméricas o metálicas), que en ocasiones, no son los mejores candidatos para trasportar un fármaco de manera eficiente y segura. En este trabajo se pone en evidencia la necesidad de desarrollar nuevos materiales, con características especificas, como las redes metal orgánicas, MOF por sus siglas en inglés (metal organic framework). Las MOF constituyen un grupo de materiales cuyas propiedades pueden ser reguladas según se requiera en cada aplicación. Desde el punto de vista estructural, el diseño de las MOF depende del centro metálico y el ligando orgánico que las constituyen, los cuales pueden aportar características fisicoquímicas acordes al fármaco que se desee encapsular, para luego ser liberado en el organismo. Estos materiales pueden ser sintetizados de manera sencilla a un bajo costo; además, sus propiedades pueden modularse desde la síntesis o bien pueden funcionalizarse, todas estas características constituyen ventajas que podrían superar a los materiales existentes.

International audience; A comparison of the adsorption of water, methanol, and ethanol polar vapors by the flexible porous chromium(III) terephthalate MIL-53(Cr) was investigated by complementary techniques including adsorption gravimetry, ex situ X-ray powder diffraction, microcalorimetry, thermal analysis, IR spectroscopy, and molecular modeling. The breathing steps observed during adsorption strongly depend on the nature of the vapor. With water, a significant contraction of the framework is observed. For the alcohols, the initial contraction is followed by an expansion of the framework. A combination of IA analysis, X-ray diffraction, and computer modeling leads to the molecular localization of the guest molecules and to the identification of the specific guest-guest and host-guest interactions. The enthalpies of adsorption, measured by microcalorimetry, show that the strength of the interactions decreases from ethanol to water. Differential scanning calorimetry experiments on an EtOH/H(2)O mixture suggest a selective adsorption of ethanol over water.

A general study of the adsorption of n-alkanes in the flexible metal organic framework (MOF) MIL-53 is presented. The roles of the length of the alkyl chain (n = 1-9), the nature of the metal (Al, Cr), and temperature were investigated. The shape of the adsorption curves is driven by the alkyl chain length of the n-alkanes. While traditional type-I isotherms are observed for short alkanes (n = 1, 2), adsorbates with longer chains induce clear substeps in the isotherm curves whose positions depend on the chain length. Such substeps are due to a breathing phenomenon, as proven by ex situ X-ray diffraction analysis. They strongly depend on the amount of adsorbate in the pores and on the nature of the metal (Al, Cr), which, for a given alkane, leads to a strong change in the substep positions despite the similar characteristics of the two metals. The adsorption kinetics are highly sensitive to small variations in temperature. Their detailed analysis in different regions of the isotherms shows in some cases the existence of distinct diffusion regimes and/or conformations within the flexible phases.

A one-pot metathesis reaction between trimesic acid sodium salt and Cu(NO3)(2) to yield [Cu-3(BTC)(2)] (HKUST-1) in moderate to good yields, even at room temperature (r.t.) is presented, herein, for the first time. To determine if the basic nature of the metathesis reaction afforded any new physicochemical properties to HKUST-1, three variables were monitored: a) the energy source either from i) ultrasound (US), ii) stirring at room temperature (SRT) or iii) solvothermal (ST) treatment, b) the reaction solvent and c) the reaction time. The metathesis reaction provided DMF center dot H2O, EtOH center dot H2O or MeOH center dot H2O solvates. The compounds were thoroughly characterized by FTIR, XRD, nitrogen adsorption BET surface areas and TGA/DSC data, which indicated the formation of [Cu3(BTC) 2] MOFs in eight out of ten synthetic entries. Low-pressure hydrogen uptake experiments revealed values as high as 2.44 wt% for the [Cu-3(BTC)(2)] EtOH center dot H2O solvates. The [Cu-3(BTC)(2)] MeOH center dot H2O and [Cu-3(BTC)(2)] EtOH center dot H2O solvates possess high surface areas, the latter being the metathesis prepared MOF with the least H(2)OACu coordination according to TGA, DSC and a thermal desorption gas chromatography-mass spectrometry (GC-MS) coupled technique. This resulted in a material with less chemisorbed H2O and better H-2 adsorption capability.