Sustainable Chemistry

This study presents an integrated two-step synthetic protocol for the conversion of coconut and palm oils into high-value bio-based hydrocarbons, alcohols, and aldehydes. The process employs alkaline hydrolysis followed by Kolbe electrolysis. Under reflux in an EtOH-KOH system, both oils were quantitatively converted into their constituent fatty acid mixtures (C16–C18:1 for palm oil and C8–C18:1 for coconut oil) with yields up to 88% and 92%, respectively. The resulting intermediates were characterized via GC–MS. Subsequently, galvanostatic Kolbe electrolysis (100 mA) was performed using custom platinum electrodes in binary and ternary solvent systems. High substrate conversions (>86%) were obtained, and the organic product distribution reached up to 73% and 74% relative hydrocarbon selectivity for palm and coconut oil derivatives, respectively, in a ternary MeOH/EtOH/H₂O system. However, operating under excess charge yielded isolated hydrocarbon mass yields of 8–20% (with up to 18% Kolbe dimers) alongside medium- and long-chain alcohols and aldehydes. This integrated protocol demonstrates a scalable and tunable route for converting vegetable oils into high-purity bio-based chemicals.

Allophane, halloysite, and imogolite are aluminosilicate clays, whose structures mainly contain silicon and aluminum. However, their morphologies differ markedly: allophane occurs as hollow/porous nanospheres, imogolite as single-walled aluminosilicate nanotubes, and halloysite as multi-walled rolled nanotubes. These structural contrasts control surface hydroxyl chemistry, pH-dependent (variable) charge, porosity, and the accessibility of inner/outer surfaces, which in turn govern the performance of adsorption, catalysis/photocatalysis, enzyme immobilization, biomedical delivery, hydrogel, and membrane technologies. Here, we critically synthesize recent advances with an emphasis on structure–property–function relationships and on the transition from natural/synthesized extracts to engineered/functionalized nanohybrids. At the end of the review, we show that targeted control of morphology, surface charge, and surface functionalization consistently shifts selectivity and stability, enabling application-specific optimization. We also highlight priorities for future research and explain how they contribute to Sustainable Development Goals.

Safe drinking water remains an issue all around the world, especially in arid countries that require seawater desalination to obtain safe water. This research seeks to analyze water quality at the major stages of an SWRO plant, i.e., raw seawater intake, RO permeate, reject brine, and distribution network water. For the study, conventional physicochemical methods of water quality analysis, as well as electrochemical impedance spectroscopy, were used. Four water samples were taken at different stages of the treatment process: raw seawater (feed water), RO permeate, reject brine, and distribution network water. Physicochemical parameters, such as pH, electrical conductivity, total dissolved solids (TDS), major ions (Na⁺, Cl⁻, Ca²⁺, and Mg²⁺), and heavy metals (Zn, Cu, Cr, and Hg) concentrations, were evaluated. Electrochemical impedance spectroscopy was used to investigate ionic transport, dielectric relaxation, and interfacial polarization mechanisms within the tested solutions. It has been shown that RO membranes are capable of rejecting major ions up to 95–99%, as can be seen in the low values of conductivity and TDS of RO permeate. EIS analysis also allowed for identifying specific electrochemical characteristics of all four types of water, with brine being characterized by the highest polarization rates and relaxation times.