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Mango seeds from agro‐industry represents an environmental problem due to the amounts of by‐products produced. Conversely, poly (lactic acid) (PLA) is a potential green alternative to conventional plastics. The goal of this study aimed to develop a biocomposite based on PLA and mango's by‐product for rigid packaging. Six biocomposites are obtained by extrusion/injection processing using formulations with PLA as a matrix and up to 20% by weight of mango seed's by‐products. The materials are characterized by chemical and physical analysis; scanning electron microscopy/energy dispersive X‐ray, X‐ray diffraction; Fourier transform infrared spectroscopy (FTIR); thermal gravimetric analysis/differential thermogravimetry; differential scanning calorimetry (DSC), and mechanical analysis. FTIR bands and DSC transitions related to starch are higher in the kernel, while more cellulose bands are found in the integument. Kernel presented thermal degradation in the biocomposites, the sample PLA+20 wt% kernel. For the other compositions, it is possible to observe that they could keep their morphology. Significant improvements in both mechanical and barrier properties are found in the formulation with 20 wt% integument (up to 38% in elastic modulus). Therefore, this study suggests that biocomposites developed from PLA / Integument / Kernel have potential as a new biomaterial for rigid food packaging systems. [ABSTRACT FROM AUTHOR]

The organophilization of clays to increase interfacial interactions is a typical practice when the objective is its encapsulation with a polymer. This work intend to synthesize and characterize an organo-palygorskite-Fe 3 O 4 , to change the hydrophilicity of the material and investigate its efficiency in the removal of two anionic dyes from aqueous solution with the aim to use this material to treat wastewater contaminated with dyes. The organophilization of modified palygorskite–Fe 3 O 4 was done with a cationic surfactant (cetyl trimethylammonium bromide, CTAB) and the material obtained was characterized by XRF, SEM, XRD, FTIR, Nano Zetasizer, density, BET surface area, TGA/DTA and contact angle measurements. XRF and FTIR confirmed the presence of carbon in the modified palygorskite–Fe 3 O 4 nanoparticles while XRD showed new crystalline phases from CTAB. Furthermore, a positive zeta potential value appeared and an inversion in the nanoparticles' hydrophobicity happened due to the increase of organic carbon content in the organo-palygorskite-Fe 3 O 4 . The adsorbed anionic dye on organo-palygorskite-Fe 3 O 4 may be completely recovered by the action of a magnet, showing an excellent adsorptive property and economical alternative adsorbents to treat dye wastewater. The negative values calculated for the free energies of adsorption indicate that the adsorption of methyl orange and indigo carmine on the active sites of organo-palygorskite-Fe 3 O 4 surface was spontaneous and that the indigo carmine had the best interaction with the magnetic organo clay. [ABSTRACT FROM AUTHOR]

Recently there has been considerable interest in magnetic sorbents materials, which is added excellent capabilities such as sorption and magnetic response to an applied field. Accordingly, palygorskite nanoparticles were covered by magnetite using a co-precipitation technique and characterized by: X-ray fluorescence (XRF), X-ray diffraction (XRD), surface analysing and scanning electron microscopy (SEM) with element analysis and mapping, particle size, pore surface area (BET), density, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and zeta potential. Additionally, magnetic properties were studied by SQUID magnetometer, magnetic force microscopy (MFM) and also using a simple experimental setup. Magnetic nanoparticles produced had average diameters in a nanometric range. The amount of iron present in the nanoparticles increased by six times after the magnetization and a superparamagnetic behavior was exhibited with high saturation magnetization, from 4.0 × 10 −4 Am 2 /kg to about 20 Am 2 /kg. A weight loss was also observed around 277 °C–339 °C by TGA, indicating a structural change from magnetite to maghemite, which confirms the magnetization of palygorskite. Batch adsorption experiments were carried out for the removal of methylene blue cationic dye from aqueous solution using pure and covered by magnetite palygorskite nanoparticles as adsorbents. Furthermore, about 90% of methylene blue was removed within 3 min using magnetized palygorskite. [ABSTRACT FROM AUTHOR]

Highlights: [•] Palygorskite was characterized by chemical analysis, morphology and particle size. [•] Using XRD pattern, it was observed that palygorskite is the main mineral. [•] SEM images show the fibrous aspect of the palygorskite and ribbon-like structures. [•] Palygorskite is positively charged below pH 8 and becomes negatively charged above it. [ABSTRACT FROM AUTHOR]

Biodiesel stands out as a promising contender in the quest for renewable energy solutions, offering a greener alternative to traditional fossil fuels. Derived primarily from the transesterification of vegetable oils or animal fats, biodiesel offers an eco-friendly energy avenue with a minimized carbon footprint. Catalysts are central to the success of this process, which significantly enhance yield rates. Geopolymers, traditionally associated with construction applications due to their inorganic nature, have been derived from aluminosilicate sources activated using alkaline solutions. However, recent advancements spotlight geopolymers in a new light, emphasizing their prospective role as nanocatalytic agents for biodiesel synthesis. This paradigm shift suggests improved production efficiency and an innovative method of repurposing industrial waste. This study centers on the pioneering application of geopolymers, fortified with magnetite, as potent heterogeneous catalysts for biodiesel generation from soybean and safflower oils. By leveraging a meticulously crafted geopolymer matrix—consisting of metakaolin, sodium hydroxide, and magnetite—this research replaced traditional catalysts with this advanced nanostructured geopolymer variant in the biodiesel methylation process. The research delved deep to ascertain the prime synthesis conditions. Furthermore, utilizing cutting-edge machine learning methodologies provided an analytical lens to navigate the extensive experimental data, thereby fine-tuning the optimization trajectory. One of the salient takeaways from this research is the validation that geopolymer catalysts, rooted in kaolinite, can be ingeniously tailored to ensure elevated biodiesel yields across a spectrum of oil sources, underscoring their unparalleled efficiency and versatility in the biofuel domain. [ABSTRACT FROM AUTHOR]

The photocatalytic properties of copper ferrites can be exploited in the degradation of organic contaminants in aqueous media, such as methylene blue. The interaction of ferrites with electromagnetic radiation results in the formation of chemical species capable of acting in the degradation of methylene blue molecules. The incorporation of these nanomaterials into geopolymeric matrices makes it possible to produce polymeric nanocomposites with improved properties. Geopolymers loaded with different percentages of copper ferrites were placed in contact with a solution of methylene blue, exposed to UV light and it was possible to observe photocatalytic activity in the degradation of this dye. Analysis in a UV–Vis spectrophotometer, at the maximum absorbance wavelength of the dye equivalent to 670 nm, showed that the geopolymer loaded with 2% copper ferrites was more effective in degrading methylene blue. These results display the potential of copper ferrite-loaded geopolymers as viable photocatalysts for organic pollutant remediation. [ABSTRACT FROM AUTHOR]

The research of polylactic acid (PLA) packaging materials with high degradation rate is important toward high rate biodegradable packaging materials. The samples (PLA-mango seed residue-clays) were evaluated by degradation analysis (in water and in soil) followed by FTIR, NMR, SEM/EDS and Texturometer analysis. The samples degradation was more effective in water than in soil, probably due to a coupled effect of water and microbiological degradation. PLA-kernel-tegument samples degraded more than PLA-kernel samples due to the effectiveness action of kernel and tegument together in the samples' degradation. PLA-Bofe samples degraded less than PLA-kernel-tegument and PLA-kernel-tegument-Bofe samples, PLA-Chocolate clay (Bofe and Chocolate are organo-montmorillonite clays) samples degraded more than PLA-kernel-tegument-Chocolate samples and less than PLA-kernel-tegument samples, probably due to multiples interaction among the Chocolate clay and mango components. The FTIR bands after samples hydrolytic and soil degradation presented low intensity, probably indicating materials degradation. New bands were observed after soil degradation, most likely related to accumulated soil and band displacement, indicative of samples degradation. The NMR relaxation data confirm the degradation process observed form the other techniques, observing the changes in the values of proton relaxation data for all samples, comparing the values after and before been degraded. [ABSTRACT FROM AUTHOR]

Geopolymers are a type of inorganic polymer that typically have a monochromatic appearance. This study investigates the formation of artificial chrysocolla by immersing these materials in Cu(II) ion solutions. The resulting synthetic chrysocolla possesses magnetic properties and characteristic silicate bands in its structure, indicating geopolymerization and a similarity to natural chrysocolla. Furthermore, the inclusion of copper and zinc ferrites in the nano-modified geopolymer matrix enhances its properties and potential antiviral properties. The antiviral test results show that synthetic chrysocolla based on nano-modified geopolymers has a mild antimicrobial effect. However, more testing is needed to determine its effectiveness against bacteriophage, as bacterial growth was observed in the area where the nano-modified geopolymer bacteriophage blend was applied. In addition to its potential antiviral properties, synthetic chrysocolla's porous structure allows it to act as an adsorbent, making it useful in the development of antiviral filters. Artificial chrysocolla can be obtained through a geopolymeric matrix by immersing it in a solution of Cu(II) ions, which can occur by ion exchange of the ions present in the aluminosilicate structure with Cu(II). Neutralization of the geopolymer matrix by washing with distilled water is required prior to immersion to ensure proper formation of chrysocolla and not copper(II) hydroxide on the geopolymer surface. Overall, this study provides evidence for the successful preparation of nano-modified synthetic chrysocolla from geopolymers and ferrites, with properties and chemical composition similar to those of natural chrysocolla. The presence of copper ions in its composition and the incorporation of copper and zinc ferrites can contribute to its use as a resource to combat viral pathogens. [ABSTRACT FROM AUTHOR]

Magnetite nanoparticles are widely used in current medicine because their magnetite properties allow several uses as drug delivery systems, contrasts in imaging tests, and even for magnetohyperthermia. However, magnetic nanoparticles possess meager Zeta potential, presenting a strong tendency to agglomerate. For clinical use, they must be covered with a biocompatible material to maintain colloidal stability, without, however, altering its magnetic properties. Thus, for biomedical applications in general, magnetic nanocomposites are more interesting than pure magnetite. The present work applies poly(butylene succinate) (PBS), as a coating on magnetite nanoparticles, aiming to increase their biocompatibility. PBS is a polymer obtained from renewable sources, being entirely suitable for pharmacological uses. In this work, the synthesis of ricinoleic acid from natural castor oil is carried out through the saponification method and subsequent acid hydrolysis. In turn, the synthesis of magnetite nanoparticles is performed by coprecipitation. Then, by an acid‐base reaction, the nanoparticles are treated with ricinoleic acid. Soon afterward, toluene diisocyanate is used to produce bonding between the modified particles and PBS. Fourier‐transform infrared spectroscopy confirms the synthesis of the material. Also, scanning electron microscopy and dynamic light scattering experiments are performed. The obtained results allow inferring the success in the preparation of the pursued hybrid material. [ABSTRACT FROM AUTHOR]

Abstract: Asphaltenes are the main components of crude oil, and their chemical structures are very difficult to be analysed and characterised. Fourier Transform Infrared Spectroscopy (FT-IR) is one of the available analytical methods for interpreting the structure of asphaltenes and it has been used to characterise functional groups in these compounds. In the present work, FT-IR spectra of alkyl-benzenes, obtained both experimentally and theoretically (by quantum mechanic modelling), were studied using a semi-empirical software AM1. Based on these spectra, the linear relationship between the intensity ratios at 2927 and 2957 cm−1, and the ratios nCH2 / mCH3 from carbon chains of alkyl-benzenes, have been analysed to determine the terminal aliphatic chains of asphaltenes. This methodology was satisfactorily evaluated using molecular average structures found in the literature. Also, using both theoretical IR and experimental DRIFTS spectra, with deconvolution, the relationship between methylene and methyl groups, which are part of the aliphatic chains, were calculated for three types of Brazilian vacuum residue asphaltenes. [Copyright &y& Elsevier]

In this work, intelligent materials were developed from the cotton fabric modified with polyaniline (PAni). PAni was used in different oxidation states (Emeraldine Salt, Emeraldine, Leucoemeraldine and Pernigraniline Base). The obtained materials were tested as colorimetric hydrogen sulfide gas sensors. The intelligent fabrics were analyzed by Infrared Spectrometry (FTIR), X‐ray powder diffraction (XRD), Thermogravimetric Analysis (TGA), Energy Dispersive X‐Ray Spectroscopy (EDS), Optical Microscopy and Electrical Resistivity Analysis. Smart fabrics were exposed to hydrogen sulfide gas, and colorimetric analyses were performed before and after exposure to identify fabrics capacity of detection. The obtained results allowed inferring that the best material was the one modified with Emeraldine base. This low‐cost material can be easily obtained, constituting a valuable hydrogen sulfide gas detection tool. [ABSTRACT FROM AUTHOR]