Toxic pharmaceutical pollutants, such as nicotine, represent a significant threat to natural water sources due to their continuous discharge. To address this issue, clay minerals and their composites have demonstrated exceptional adsorptive and remedial capabilities for wastewater purification. This research focused on developing green clay-polymeric adsorbents for the efficient removal of pharmaceutical pollutants from industrial wastewater. The synthesis involves creating halloysite nanotube–polythiophene nanocomposites through a green and cost-effective method using vapour polymerization and a solvent-free, ball-milled technique for the adsorptive removal of nicotine from wastewater. The investigation evaluates the impacts of preparation, modification and environmental conditions on the adsorptive performance of these clay-based nanocomposites compared to pure polythiophene. The polymerization process was evaluated by varying the vapour polymerization holding time for a fixed amount of oxidant (FeCl3) and halloysite nanotube (HNT) to investigate the impacts of monomer vapour exposure time on the polymerization of nanocomposites. Following the characterization of the synthesized adsorbents using various methods, the study investigated the impacts of various parameters (e.g. adsorbent dosage, pH and contact time) on the adsorption capabilities of the materials on a laboratory scale. The results revealed that the incorporation of HNT improved the adsorbing performance of nanocomposites. The pH, absorbent concentration and contact time directly affect nicotine adsorption. Significantly, halloysite–polythiophene 3 with a 2 h polymerization duration demonstrated the maximum adsorption efficacy of 78.94% at pH 10 after a 24 h contact time. The environmentally friendly halloysite-based nanocomposite shows promising potential as an effective adsorbent for pharmaceutical pollutant (nicotine) removal from aquatic environments.

The synthesis of copper citrate complex supported on acid-activated vermiculite was investigated with a view to preparing an efficient, mild, robust and recyclable catalyst for the Biginelli reaction. The new catalyst was characterized by X-ray fluorescence (XRF), infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), and scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDS). Copper citrate supported over activated vermiculite (AAVrm-Cu2) showed good catalytic activity in the synthesis of 3,4-dihydropyrimidinones. The catalyst can be separated easily from the reaction mixture by filtration and retains its catalytic activity for up to five cycles of reaction with no apparent decrease in yield.

Carbon nanotubes (CNTs) were synthesized by Chemical Vapor Deposition (CVD) from diethyl ether, butanol, hexane and ethyl acetate. A quartz tube with a stainless steel tube catalyst core with 0.019 m diameter and 0.6 m large formed the reactor. To avoid combustion, argon was used as the carrier gas. Time process ranged 30 to 60 min. The range of CNTs synthesis temperature was 680-850 °C for different precursors. Scanning Electron Microscopy micrographs have demonstrated tangled CNTs growth in all samples, thus presenting difficult length measurement. The CNTs diameters from diethyl ether are 45-200 nm, butanol diameter range from 55-230 nm, hexane diameter range is 50-130 nm and ethyl acetate range from 100 to 300 nm. Carbon content for all samples was higher than 93 %, CNTs from butanol showed carbon concentration up to 99%. FTIR, Raman and X-Ray Spectroscopies spectra for all samples demonstrated the characteristics signals present in carbon nanotubes. This research proposes a simple, effective and innovative method to synthesize CNTs by CVD on iron stainless steel catalyst in combination with diethyl ether, ethyl acetate, butanol and hexane as precursors by applying the principles of green chemistry, sustainability and its ease to be scaled.

Most chemical reactions on asteroids, from which meteors and meteorites originate, are hypothesized to occur primarily in the solid mixtures. Some secondary chemical reactions may have occurred during the periods of the aqueous alteration of the asteroids. A myriad of organic compounds have been isolated from the meteorites, but the chemical conditions during which they were formed are only partially elucidated. In this paper, we propose that numerous meteoritic organic compounds were formed by the solventless and solid-state reactions that were only recently explored in conjunction with the green chemistry. A typical solventless approach exploits the phenomenon of the mixed melting points. As the solid materials are mixed together, the melting point of the mixture becomes lower than the melting points of its individual components. In some cases, the entire mixture may melt upon mixing. These reactions could then occur in a melted state. In the traditional solid-state reactions, the solids are mixed together, which allows for the intimate contact of the reactants, but the reaction occurs without melting. We have shown various examples of the known solventless and solid-state reactions that are particularly relevant to the meteoritic chemistry. We have also placed them in a prebiotic context and evaluated them for their astrobiological significance.