Tomatoes are among the most widely consumed and economically significant fruits in the world. However, the extensive use of pesticides in their cultivation has led to the contamination of the peels, posing potential health risks to consumers. As one of the top global producers, consumers, and exporters of tomatoes, Mexico requires rapid, non-destructive, and real-time methods for pesticide monitoring. In this study, a detailed characterization of six pesticides using Raman and Fourier Transform Infrared (FT-IR) spectroscopies was carried out to identify their characteristic vibrational modes. The pesticides examined included different chemical classes commonly used in tomato cultivation: organophosphorus (dichlorvos and methamidophos), pyrethroids (lambda-cyhalothrin and cypermethrin), and carbamates (methomyl and benomyl). Tomato peel samples were examined both before and after pesticide application. Prior to treatment, the peel exhibited a well-organized polygonal structure and showed the presence of carotenoid compounds. After pesticide application, no visible structural damage was observed; however, distinct vibrational bands enabled the detection of each pesticide. Organophosphorus pesticides could be identified through vibrational bands associated with P-O and C-S bonds. Pyrethroid detection was facilitated by benzene ring breathing modes and C=C stretching vibrations, while carbamates were identified through C-N stretching contributions. Phytotoxicity testing in the presence of pesticides indicates no significant damage during the germination of tomatoes.

Transparent high-performance polymers are essential to avoid damage in automotive headlights when exposed to environmental conditions. An approach involving the synthesis of reinforced interpenetrating polymer networks (IPNs) based on poly(methyl methacrylate) (PMMA)/poly(urethane) (PU) with crystalline cellulose (C) is here proposed. The valorization of single-use cups used for cold beverage applications into reinforcement nanoparticle agents is studied through structural and morphological analysis, revealing intermediate crystallinity (52.51%) with a mixture of Iα (52.9%) and Iβ (46.3%) polymorphs in which the initial fiber had no chemical modification after the involved pretreatments. The effect of dispersing 0.1 wt% of C (d = 29 nm and L= 85–200 nm) into 50/50 and 80/20 PMMA/PU ratios is studied as a reinforcement agent under aging and environmental conditions (ASTM D1435-20) for 672 h. PMMA₈₀/PU₂₀ (σ =4 MPa, ε = 54%, E = 7 MPa) led to lower mechanical properties than PMMA₅₀/PU₅₀ (stress σ =14 MPa, strain ε = 94%, E = 83 MPa). PMMA₅₀/PU₅₀/C is reinforced in σ and ε with C addition (σ = 19 MPa, ε = 41%, E = 585 MPa) while PMMA₈₀/PU₂₀/C reduces both (σ = 3 MPa, ε = 51%, E = 5 MPa). This study indicates that aging increases stress while maintaining strain in the first but decreases in the second. The optical properties indicate no severe damage after aging.

In recent years, advances in materials engineering based on adaptive electronics have found a new paradigm to optimize drawbacks in signal processing. A two-layer MnO/ZnO:Zn heterostructure envisioned for frequency adaptive electronic signal processing is synthesized by sputtering, where the use of internal states allows reconfigurability to obtain new operating modes at different frequency input signals. X-ray diffraction (XRD) analysis is performed on each layer, revealing a cubic structure for MnO and a hexagonal structure for ZnO:Zn with preferential growth in [111] and [002] directions, respectively. Scanning electron microscope (SEM) micrographs show that the surface of both materials is homogeneous and smooth. The thickness for each layer is determined to be approximately 106.3 nm for MnO, 119.3 nm for ZnO:Zn and 224.1 nm for the MnO/ZnO:Zn structure. An electrical characterisation with an oscilloscope and signal generator was carried out to obtain the time-response signals and current-voltage (I–V) curves, where no degradation is detected when changing frequencies within the range of 100 Hz to 1 MHz. An equivalent circuit is proposed to explain the effects in the interface. Measurements of switching speeds from high resistance state (HRS) to low resistance state (LRS) at approximately 17 ns, highlight the device’s rapid adaptability, and an estimated switching ratio of approximately 2 × 10⁴ indicates its efficiency as a memristive component. Finally, the MnO/ZnO:Zn heterojunction delivers states that are stable, repeatable, and reproducible, demonstrating how the interaction of the materials can be utilised in adaptive device applications by applying frequencies and internal states to create new and innovative design schematics, thus reducing the number of components/connections in a system for future sustainable electronics.

Interface phenomena in oxide electronics are of utmost importance due to the interactions that are present between the materials and can offer interesting electrical behavior for adaptive oxide devices. Thin films were synthesized on a Si (100) n-type substrate by Sputtering where the layers of manganese oxide are obtained through thermal oxidation at medium temperatures $(\mathbf{T} < \mathbf{500}^{\circ}\mathbf{C})$ and later on, a layer of ZnO:Zn is deposited. X-Ray Diffraction (XRD) and Raman spectroscopy are done to investigate the structure of the Mn; the layers of manganese exhibit different phases of oxidation caused by the thermal process. To study the interface phenomena, an electrical characterization (current – voltage curves) is done to understand what happens in the interface of Mn x O y /ZnO. In one of the IV curves obtained of a ZnMnSi structure, a similar curve to the characteristic one of a diode is observed, thus, this work intends to demonstrate the use of Mn and Zn as important metals for oxide electronics and the development of electronic adaptive devices.

In this work, a bi-layer MnO/ZnO:Zn structure with an approximate thickness of 100 nm for each layer has been successfully synthesized by sputtering. Changes in the electrical properties were evaluated for the potential application for solid-state capacitors as electrodes. The characterization of the layers is carried out through X-Ray Diffraction (XRD), which provides valuable insights into the structural properties. An electrical study employing Frequency Response Analysis (FRA), Bode plots, Voltagetime (V-t), and Current-Voltage (I-V) graphs is conducted to thoroughly examine and understand the electrical behavior of the synthesized layers. XRD results show a MnO phase for the Mn sputtered layer and a mild distortion of the ZnO lattice for the ZnO:Zn co-sputtered layer due to Zn atoms. The electrical study provides a Bode plot where at f100 KHz. At the cutoff frequency (fc) a capacitance value of 142 pF is calculated. The attenuation and reactance effects are also showed in the V-t and I-V graphs. Finally, the time constant (τ) is calculated with a square +5V input signal where also a value of capacitance is obtained as 134 pF, indicating a ±10% of tolerance for the value of capacitance at high frequencies (f≥500 KHz) for the film, where reactance effects can be improved with several MnO/ZnO:Zn nanostructures as electrodes in series to add the capacitor value revealing a potential application for the structure for solid-state supercapacitors.

Although crystalline nanocellulose (CNCs) can be extracted from different resources, the employed pretreatments, which disrupt the inter- and intramolecular physical interactions, depend on the biomass sources. This study aims to valorize Aloe Vera (AV) rinds into cellulose and crystalline nanocellulose (CNC) employing two approaches during hydrolysis: sulfuric acid (CNC_SA) and citric acid (CNC_CA) after 30, 60, and 90 min of reaction. The effects of pretreatments and hydrolysis time on the functional groups and hydrogen bonding in biomass are discussed. Crystalline structure (polymorph type), crystallinity, thermal stability, morphology, particle size, and metal presence are also analyzed. A transformation from type I into II polymorph was achieved, where the intermolecular interactions governing cellulose were increased in CNC_SA and were almost maintained in CNC_CA. Properties based on the structure, thermal properties, particle size, and metal presence indicate that the CNC_SA30 and CNC_CA90 samples displayed potential application as reinforcement agents for other types of polymers having no more melting points of 160 and 220 °C, respectively.