Sargassum is a type of marine algae that has caused environmental problems in Mexico because it arrives in high quantities along the Mexican coast, especially in the Mexican Caribbean. This situation has become an environmental and economic problem, impacting tourism and other activities. As a result, it is reasonable to try to find an application for these algae. Recently, some applications in civil construction, cosmetics, and the food industry, among others, have been reported. The present work evaluates the thermal and structural properties of new polypropylene (PP)–Sargassum-based composites. Also, the effect of adding calcium stearate (CS) to increase the interaction between PP and Sargassum particles was investigated. PP–Sargassum particle composites were prepared by a melt mixing process, and the properties of these composites were evaluated using thermal techniques such as dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and infrared spectroscopy (FTIR). The DMA results showed that composites with low concentrations of Sargassum particles perform better than those with higher concentrations. When CS was added to composites, there was a significant improvement in storage modulus compared with composites without CS. This was attributed to the good adhesion of the particles to the matrix because the mobility of macromolecules increased in the presence of CS. The thermal stability of PP–Sargassum particle composites decreases when the amount of particles increases, and the addition of CS does not positively affect the thermal behavior of composites. The findings open the possibility of using Sargassum particles in new applications of these algae as a polymer additive to generate sustainable materials.

The use of biowaste materials as additives in polymeric matrices has generated interest. Garlic is a seed that has wide application areas, not only in the food industry, because it has good bactericidal and antioxidant properties. Polypropylene (PP) is a commodity polymer that has a wide range of applications, including containers, construction materials, automotive parts, domestic issues, etc. In the present work, the obtaining of composite materials based on a Polypropylene with a medium melt flow index as a matrix and as a reinforcing agent garlic husk particles (GHP). The addition of GHP in different contents was evaluated (2 to 10 PHR), and the composites were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and X-ray diffraction (×RD). According to the results, the thermal stability of PP-GHP decreases with the GHP, in addition to the results of DSC and XRD, that showed that the crystallinity of PP-GHP composites was higher compared to the pristine PP. DMA results allow us to identify that the addition of GHP generates a reinforcing effect on PP matrix, which means that this waste material can be considered a bioadditive with positive effects on polymeric matrices.

Magnesium-based alloys are considered to be promising materials for the fabrication of temporary bone repair medical implants. The AZ31 magnesium-based (AZ31-Mg) alloy contains 3% aluminum and 1% zinc in its microstructure, which gives it mechanical strength and corrosion resistance. Nonetheless, the corrosion rate is high, which can lead to implant failure due to rapid degradation, which triggers the release of harmful metal ions. In the present work, a passive layer was obtained on the AZ31-Mg alloy, and subsequently, a cerium oxide (CeO₂) coating was deposited through a chemical conversion treatment using 0.01 M CeO₂ as a precursor. Based on X-ray photoelectron spectroscopy, the calculated amount of Ce(IV) and Ce(III) present in AZ31-Mg(OH)₂/CeO₂ was 93.6% and 6.4%, respectively. AZ31-Mg(OH)₂/CeO₂ showed improved corrosion resistance compared with the bare sample. The in vitro assessment of MC3T3-E1 pre-osteoblast cell viability showed that AZ31-Mg(OH)₂/CeO₂ was biocompatible after incubation for 24 and 72 h. The results revealed that the CeO₂ coating confers greater electrochemical stability and biocompatibility properties, mostly due to the presence of Ce⁴⁺ ions.

In recent years, the applications of lignocellulosic biomass (LCB) have substantially increased due to its versatility in different areas of study and interest. Therefore, it is evident that the delignification pretreatment of LCB is fundamental to assure the viability and commercial quality of the final product for different industrial uses. The efficiency of delignification, the obtainment of the desired products, and the required quality depend mainly on the type of pretreatment and the method used. This paper presents a state-of-the-art overview of physical, chemical, organic, biological, hybrid (combination of two or more pretreatments), and other novel pretreatments for the delignification of different lignocellulosic biomass. Additionally, the conditions necessary for the application of the pretreatments, the effect of the variables involved, and the advantages and disadvantages of each method are discussed. Finally, advances in the development of sustainable methods are discussed.

The extraction of materials, such as sand and gravel, required for the manufacture of concrete results in the overexploitation of natural resources and a large release of CO₂ emissions into the environment. Therefore, the search for alternatives to partially replace these aggregates has become an important issue to solve. Nonetheless, the demand for producing sustainable yet high-strength and durable concrete using alternative materials has led concrete technologists to develop high-performance concrete. These novel concretes possess superior engineering properties, such as high durability and ductility, low maintenance costs, high mechanical strength, and prolonged service life. Currently, there is significant interest in the development of concrete–polymer compounds, primarily to improve the mechanical properties of the material. In this context, the present study explores the partial replacement of fine aggregate with recycled Polyethylene terephthalate (R-PET) in different proportions to produce green structural concrete, with the aim of studying its impact on the mechanical and electrochemical properties. The mechanical properties evaluated were the compressive and flexural strengths, while the electrochemical properties were evaluated through the open circuit potential and polarization curves. The results indicated that specimens containing different R-PET percentages as a replacement for fine aggregate showed higher increases in compressive and flexural strengths. It was also found that the presence of R-PET decreased the corrosion rate of the reinforcing steel when seawater was used as the electrolyte.

Nowadays, biomass use has increased due to it being the most abundant raw material on the planet, and treating it is a difficult task, as a result of the number of existing methods and the applications’ diversification. This research work shows the results obtained using different delignification methods (physical and chemical) on water lily ((Eichhornia crassipes) fiber lignocellulosic biomass including a seldom exploited method, known as “electrohydrolysis” in order to determinate the removal efficiency of lignin and hemicellulose. The characterization of the physicochemical and morphological properties of the water lily (Eichhornia crassipes) fiber before and after the pretreatments were applied were by means of Fourier Transform Infrared (FT-IR), X-ray diffraction (XRD) and optical microscopy (OM). The results of FT-IR show a significant decrease in the bands associated with lignin and hemicellulose. By XRD, it was determined that the crystallinity of the cellulose increased by 60% for the treated samples with respect to the reference, and an increase in the surface roughness of the samples was observed by OM. In conclusion, it was determined that electrochemistry delignification is an efficient, environmentally friendly methodology to remove the soluble sugars, opening the possibility to use the water lily (Eichhornia crassipes) fiber to produce a green concrete.