Yunny Meas

The uncontrolled use of herbicides such as glyphosate (GLY) (N-phosphonomethylglycine) in agricultural production has resulted in its presence in water bodies and in negative impacts on the environment and public health. On the frame of understanding the interaction between GLY and graphite rod surfaces, this contribution relies on the study of electrochemical responses of different GLY concentrations by cyclic voltammetry under both open and closed-circuit conditions. Furthermore, the effect of the electrodes’ electrochemical pretreatment with acetic acid on the double-layer capacitance and the subsequent surface functionalization of the graphite rod materials were evaluated. The increment in GLY concentration showed a decrease in the electrochemical oxidation response associated with the adsorption of the contaminant on the surface of the graphite rod electrode and the concomitant blockage of the active sites. Electrochemical pretreatment of the electrodes with acetic acid and GLY concentration play crucial roles in electric double-layer formation due to their ability to interact with both positive and negative electrical charges. By means of optical microscope observations and Fourier Transform Infrared Spectroscopy analysis, it was possible to detect the formation of oxygenated functional groups on the electrode surfaces after the electrochemical pretreatment. Through a 2³ factorial design analysis in repetition, the factors significant in the degradation of GLY were identified. The high degradation of GLY with the pretreated electrodes can be attributed to the preferential adsorption of the zwitterionic molecule at the interface, which allowed great direct oxidation of the contaminant on the anode’s surface.

This work proposes for the first time protecting–reflecting on both sides of plated mirrors and a solution to polycarbonate surface vulnerability to weathering and scratching using tungsten disulfide (WS₂) by mechanical polishing. The ability of the dynamic chemical plating (DCP) technique to deposit Ag films at the nanometer scale on a polycarbonate (PC) substrate and its characteristics to be metallized is also shown. These deposits hold significant promise for concentrated solar power (CSP) applications. Complementarily, the application of WS₂ as a reflective film for CSP by mechanical polishing on smooth polycarbonate surfaces is both novel and practical. This technique is innovative and scalable without needing reactants or electrical potential, making it highly applicable in real-world scenarios, including, potentially, on-site maintenance. The effects of surface morphology and adhesion, and the reflectivity parameters of the silver metallic surfaces were investigated. Wettability was investigated because it is important for polymeric surfaces in the activation and metal deposition immediately after redox reactions. The flame technique improved wettability by modifying the surface with carbonyl and carboxyl functional groups, with PC among the few industrial polymers that resisted such a part of the process. The change in the chemical composition, roughness, and wettability of the surfaces effectively improved the adhesion between the Ag film and the PC substrate. However, it did not significantly affect the adhesion between PC and WS₂ and showed its possible implementation as a first surface mirror. Overall, this work provides a scalable, innovative method for improving the durability and reflectivity of polycarbonate-based mirrors, with significant implications for CSP applications.

In the present work, treatability studies were carried out with oil refinery wastewater (effluent from the secondary treatment) using electrooxidation (EO) process employing two mixed oxide anodes: SnO₂–RuO₂–IrO₂|Ti and IrO₂–Ta₂O₅|Ti. Both electrodes' performance were compared by their capacity to generate active chlorine in a synthetic solution and organic matter mineralization of a sample with an average phenol (C₆H₆O) concentration of 100 mg L⁻¹. Before degradation experiments, surface analysis, and linear sweep voltammetry tests were performed. SnO₂–RuO₂–IrO₂|Ti anode yielded higher active chlorine, reaching an average concentration of 340 mg L⁻¹ at 90 min of electrolysis and 25 mA cm⁻². On the other hand, IrO₂–Ta₂O₅|Ti anode only generated an average concentration of 200 mg L⁻¹ at 90 min and 40 mA cm⁻². Regarding the degradation experiments, SnO₂–RuO₂–IrO₂|Ti anode showed the highest dissolved organic carbon removal, ranging from 26% to 40%. In addition, through a three‐dimensional excitation–emission matrix fluorescence analysis, it was possible to elucidate the degradation of C₆H₆O and some possible polycyclic aromatic hydrocarbons present in the effluent. The results suggested that 65%–90% of the hydrocarbons and C₆H₆O present in the effluent were degraded with the SnO₂–RuO₂–IrO₂|Ti anode applying 25 mA cm⁻² within the first 30 min of electrolysis, reaching almost 99% degradation at 90 min. The EO process using SnO₂–RuO₂–IrO₂|Ti can be an alternative for tertiary treatment of oil refinery wastewater for degradation and mineralization of the remaining organic matter of secondary effluents (biological processes) via active chlorine species.

Dr. Yunny Meas tells us about his participation in the development of electrochemistry in Mexico, from his beginnings as a guest researcher at CINVESTAV in 1978, through a short period at UNAM and a prolonged period at UAM-Iztapalapa, to the current creation and maturation of CIDETEQ. He relates his professional experiences with each stage's political and economic conditions, which taught him how to focus his R&D lines to help the sustainable growth of the region and the country. Resumen. El Dr. Yunny Meas nos relata su participación en el desarrollo de la electroquímica en México, desde sus inicios como investigador invitado en el CINVESTAV en 1978, pasando un periodo corto en la UNAM y un periodo más largo en la UAM- Iztapalapa, hasta la creación y maduración actual del CIDETEQ. Relaciona las experiencias profesionales con las condiciones políticas y económicas de cada etapa, que le sirvieron de lecciones para aprender a enfocar sus líneas de I &D para ayudar al crecimiento sostenible de la región y del país.

Common bean (Phaseolus vulgaris L.) is an important crop for food security and for national economics for several countries worldwide. One of the most important factors of risk in common bean production is the fungal disease anthracnose caused by Colletotrichum lindemuthianum, which, in some cases, causes complete yield losses; this kind of plant disease is usually managed through the application of chemical products such as fungicides that are commonly not accepted by society. This rejection is based on the relationship of pesticides with health damage and environmental contamination. In order to help in solving these drawbacks, the present work proposes the use of electrochemically activated salt solutions (EASSs) as a safer pathogen control agent in crops, due to it having shown an elicitor and biostimulant effect on plants. With this background, this manuscript presents in vitro results of the evaluation of the inhibitory effect for multiple bean pathogens and in vivo results of EASS in the common bean–Colletotrichum pathosystem by evaluation of the infection severity and defense activation, such as secondary metabolite production and antioxidant activity. EASS presence in growth media had a strong inhibitory effect at the beginning of experiments for some of the evaluated fungi. EASSs showed an effect against the development of the disease when applied in specific doses to prevent distress in plants.

Common bean (Phaseolus vulgaris L.) is an important crop for food security and for national economics for several countries worlwide. One of the most important factors of risk in common bean production is the fungal disease anthracnose caused by Colletotrichum lindemuthianum, which in some cases, causes complete yield losses; this kind of plant disease is usually managed through the application of chemical products such as fungicides, that are commonly not accepted by society, this rejection is based on the relationship of pesticides with health damage and environmental contamination. In order to help in solving this drawbacks, the present work propose the use of Electrochemically Activated Salt Solutions(EASS) as a safer pathogen control agent in crops due to it have shown an elicitor and biostimulant effect on plants such as tobacco and apple. With this background, this manuscript presented in vitro results of the evaluation of the inhibitory effect for multiple bean pathogens and in vivo results of EASS in the common bean-Colletotrichum pathosystem by in vitro evaluations of the inhibitory effect for multiple bean pathogens and in vivo evaluation of the infection severity and defense activation such as secondary metabolites production and antioxidant activity. EASS presence in growth media had strong inhibitory effect, at beginning of experiment, for some of the evaluated fungi. EASS showed effect against the development of the disease when applied in specific doses to prevent distress in plants.

The lifetime of mirrors in outdoor conditions is crucial in the correct operation of any concentrating solar power (CSP) installation. In this work, the corrosion behavior of two types of metallized surfaces was studied. The first was made of a flexible polymer having a deposited reflective silver metallic film. The second was made of the same surface type with a dielectric SiO₂ protection coating by an atmospheric pressure plasma jet. Polycarbonate sheets were used as substrates on which metallic silver was deposited by the Dynamic Chemical Deposit technique. This electroless technique allowed producing the mirror finishing under environmental conditions by sequentially spraying; as aerosols projected towards the substrate surface, the activation and reducing-oxidizing solutions with rinsing after each one. The silver coatings were about 100 nm thick. Environmental and accelerated weathering degradation and salt and sulfide fogs were carried out. XPS analyses show that the corrosion products formed were Ag₂S, AgCl, and Ag₂O. It was observed that the tarnishing was initiated locally by the formation of Ag₂S columns as eruptions on the surface. Subsequently, the ions diffused through the protective layer and into the silver reflective layer, chemically reacting with the silver. The main atmospheric agents were H₂S, chloride particles, and HCl. High reflectance was initially obtained of about 95%. The obtained results suggest mechanisms for the degradation of exposed silver surfaces to moisturized atmospheres with corrosive compounds.

The formation of cerium hydroxide was studied, and its capacity as a corrosion inhibitor on aluminum substrates was evaluated. These particles were deposited by immersing the substrate in a bath with cerium nitrate and hydrogen peroxide. Four different immersion times were used to determine the differences in behavior from low concentrations to an excess of particles on the surface. The coatings were analyzed morphologically by scanning electron microscope (SEM) and optical microscope, and chemically by energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). Electrochemical corrosion analysis was studied using cyclic potentiodynamic polarization (CPP), electrochemical impedance spectroscopy (EIS), and electrochemical noise (EN). The results show that for 2 and 5 min of immersion, there was corrosion inhibition caused by the presence of cerium Ce³⁺ in the coating, but with excess cerium hydroxide particles, corrosion was favored. The presence of cerium particles favors corrosion at 30 s of immersion. This is the same case at 60 min, where corrosion was favored by the excess of Ce⁴⁺ particles on the surface.

The atmospheric pressure plasma jet (APPJ) has received attention in recent years due to its ease of incorporation into production lines, rapid application, low surface damage and use in a wide variety of materials (cardboard, textiles, metals, polymers and glass) and for being a more environmentally friendly technique than wet chemical techniques. Treatments with APPJ can be divided into two types: (a) surface modification with APPJ and (b) coating deposition with APPJ. These treatments decrease the hydrophobicity, change the surface composition and favor the growth of passive oxide films, while the coatings have excellent adhesion and good barrier properties. The APPJ–electrochemical link has been focused on the prevention of and protection against corrosion. Electrochemical studies show excellent results against corrosion, and APPJ treatment has the potential to replace procedures currently in use. This work describes the relationship between APPJ treatments and the electrochemical studies carried out on surfaces modified with this method.