The environmental problems caused by the persistence and improper disposal of single use plastics, have led the worldwide authorities to migrate into a sustainable production of bio-based materials, whose components need to be studied for proving their nature and to confirm their degradability. For this reason, the identification and monitoring degradation of five single use straws were assessed through FT-IR, TGA/DTA and SEM techniques which demonstrate that the straws tagged as biodegradable contain polymers of fossil origin in their formulation. Degradation of them was found to be influenced by polar groups, such as ester and glycosidic bonds of the biodegradable phase. The thermal stability decreased and the morphological characteristics as cracks and holes were detected after biodegradation.

The low-temperature synthesis of bricks prepared from high-siliceous clays by the method of plastic molding of blanks was used. For the preparation of brick blanks, binary and ternary mixtures of high-siliceous clays, black sand, and bottle glass cullet were used. Gray-black low-porosity and high-porosity ceramics was obtained by sintering under conditions of oxygen deficiency. It has been established that to initiate plastic in mixtures containing high-siliceous clay, it is necessary to add montmorillonite/bentonite additives, carry out low-temperature sintering, and introduce low-melting glass additives with a melting point ranging from 750 to 800 °C. The performed investigations have shown that the sintering of mixtures with a total content of iron oxide of about 5 wt% under reducing conditions at Tsint. = 800°C for 8 h leads to the formation of glass ceramics consisting of quartz, feldspars, and a phase. The main sources of the appearance of a dark color is the formation of [Fe3+O4]4- and [Fe3+O6]9- anions in the composition of the glass phase and feldspars. By changing the contents of clay, sand, and glass in sintering, it is possible to obtain two types of ceramic materials: (a) in the form of building bricks and (b) in the form of porous fillers.

One of the great challenges in the use of nanomaterials is their production at low costs and high yields. In this work aluminum nanoparticles, from aluminum powder, were produced by wet mechanical milling through a combination of different attrition milling conditions such as ball-powder ratio (BPR) and the amount of solvent used. It was observed that at 600 rpm with a BPR of 500/30 g for 12 h, it was possible to produce nanoparticles with a size close to 20 nm, while at 750 rpm with a BPR of 380/12.6 g for 12 h, nanoparticles of approximately 10 nm were obtained. Scanning and transmission electron microscopy confirmed that the milling product is an agglomeration of nanoparticles with different sizes. These results show the feasibility of obtaining aluminum nanoparticles by mechanical milling using only ethanol as solvent, avoiding hazardous by-products obtained from chemical routes, and the use of complicated methods such as laser ablation and arc discharge.

Several photocatalysts, based on titanium dioxide, were synthesized by spark anodization techniques and anodic spark oxidation. Photocatalytic activity was determined by methylene blue oxidation and the catalytic activities of the catalysts were evaluated after 70 hours of reaction. Scanning Electron Microscopy and X Ray Diffraction analysis were used to characterize the catalysts. The photocatalyst prepared with a solution of sulfuric acid and 100 V presented the best performance in terms of oxidation of the dye (62%). The electric potential during the synthesis (10 V, low potential; 100 V, high potential) affected the surface characteristics: under low potential, catalyst presented smooth and homogeneous surfaces with spots (high TiO2 concentration) of amorphous solids; under low potential, catalyst presented porous surfaces with crystalline solids homogeneously distributed.

Drug contamination in water is one of the current fields of study. Since 1990, the presence of drugs in drinking water has been a concern to scientists and public. In Mexico, these organic compounds are not efficiently removed in wastewater treatment plants; therefore, alternative methodologies have been studied that allow these compounds to have a high percentage of degradation or be completely degraded. One example of these techniques is heterogeneous photocatalysis which has obtained positive results in the degradation of drugs using ZnO nanoparticles. These are commonly selected for their electrical characteristics, even though they disperse in water and an additional unit operation is required to separate them from the liquid medium. To eliminate drugs with nano particles in a single stage, polycaprolactone-based membranes with adhered ZnO nanoparticles, by means of electrospinning, were prepared to degrade drugs such as diclofenac. The technique used has shown to efficiently break down diclofenac in 4 hours according to the capillary electrophoresis readings.

Among different possible energy sources, in the search for fossil fuel substitutes, hydrogen and fuel cells are presented as one of the most promising alternatives, with great potential, in the development of devices for the generation of clean electrical energy. Recently, lanthanum based compounds have been studied due to their interesting transport properties, which led these products to be applied as possible cathode materials in a solid oxide fuel cell. In this work, a lanthanum based material with a perovskite structure, La0.7Sr0.3Fe0.7Co0.3O3±δ (LSFC), was synthesized, from nitrates, by sonochemistry. This product was structurally characterized by powder X-ray diffraction and morphological studies were obtained by scanning electron microscopy. Results showed a nanostructured material with a crystal size in de order of 14 nm and a cubic perovskite structure with cell parameters of a = 3.8927 Å. Morphological characterization indicated a porous material formed by grains of homogeneous size, pores had an average length of 17 nm and area of 36 nm2, showing a channel shape distribution.

A series of highly attainable desymmetrized heterocyclic compounds with Donor-Acceptor-Donor-Acceptor-X (D-A-D-X) architectures were synthesized. The structures, where X corresponds to a heteroaromatic portion (pyridine, ferrocene, thiadiazolopyridine), were designed through computational analysis. Molecular geometries for all compounds were studied and parameters of charge transfer were computed in order to analyse the behaviour in each architecture. Spectroscopic properties (maximum absorption wavelengths, extinction coefficients and HOMO-LUMO gaps) were predicted and measured experimentally. UV-Vis absorption profiles and values of HOMO-LUMO optical gaps (in the vicinity of 2.0 eV), together with the computational results, are properties that position the obtained systems, as potential candidates for developing efficient photovoltaic materials based on synthetically accessible small organic molecules.

Bailey [1] proposed in 1972 that a nanoscale antenna coupled with a rectifier can harvest broad range electromagnetic radiation from visible to infrared. To incorporate this concept in practical systems, there were two main technological bottle necks that have to be overcome: antenna miniaturization and rectification in terahertz frequency. With current technology and equipment [2], we are proposing a third-generation rectenna-based solar cells composed of Ag nanocubes to harvest ambient visible and infrared electromagnetic waves coupled to ferrocene-based molecular diodes [3] capable of switching at terahertz frequency to convert this received energy into DC power. The function of these molecular diodes is two-fold: they rectify and provide an uniform nano-cavity between silver top electrode and gold bottom electrode. These nano-cavities are capable to support gap plasmon modes and absorption of light in both narrow and broad range, depending on the nanocube size and dispersion. A self-assembled monolayer (SAM) of ferrocene alkane-dithiol is deposited in this nano-cavity making it possible to form molecular sized nano-gaps well below the usual 3 nm, and this structure is robust and reproducible [4]. This SAM can be deposited directly or via a two-step click chemistry on the surface to have along with control over the orientation of the molecule. By tuning the orientation and position of the ferrocene moiety, the direction of rectification can be controlled [3]. Hence, the SAM does not only act as a rectifier but also provides mechanical support combining photonic and electrical properties. This paper focuses on studying the electrical and supramolecular structure of these molecular diode based SAMs.

Carbon steel has gained wide applications as a structural material due to its combination of strength, ductility, and low cost; in fact, this material has been studied as one of the proposals for the manufacture of radioactive waste containers in countries such as Japan, France, and the United States. One of the biggest problems of carbon steel is its susceptibility to general corrosion, while copper and its alloys, despite not having high mechanical resistance, are materials with good corrosion resistance properties. This work evaluates the reliability of protective films developed from copper nanoparticles to improve the corrosion resistance of carbon steel plates. The nanoparticles were synthesized by a chemical reduction method using copper sulphate (CuSO4) as a precursor, sodium borohydride (NaBH4) as a reducing agent, and citric acid as an antioxidant. These nanoparticles were characterized by Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM), as well as by Dynamic Light Scattering (DLS) before and after being treated with citric acid. Finally, they were deposited on the carbon steel surface by Electrophoretic Deposition using a current of 0.5 mA/cm2. The protective capacity of the films developed from copper nanoparticles was evaluated by means of Electrochemical Impedance Spectroscopy and Linear Polarization Resistance techniques in 0.1 M HCl solution.