Benign Solvent Research Articles

The Reactivity of Acceptor-Acceptor Diazo Pyrazolones with Allyl Thioethers under Visible Light: Access to Homoallyl Sulfides, Spiropyrazolones - Pesticide Analogues and Photoflow Synthesis.

The novel reactivity of a less selective and more reactive acceptor-acceptor kind of diazo pyrazolone (DIPOL) has been explored under visible light for the first time. We have successfully demonstrated the reaction of DIPOL and different allyl thioethers under blue light to construct a wide variety of products including a pesticidal analogue exclusively in excellent chemoselectivity in good to excellent yields. Moreover, possible side products emanating from ketene were not observed. This protocol works smoothly in an environmentally benign solvent under inert free conditions. The practicality of the protocol has been extended to a photoflow reaction, and also, the reaction works smoothly under the direct exposure of sunlight.

Simple simultaneous analysis of various cardiovascular drug mixtures with vincamine: comparative eco-friendly assessment

The development of two eco-friendly analytical methods for the simultaneous determination of eight cardiovascular drugs; hydrochlorothiazide (HCT), captopril (CPL), lisinopril (LSP), valsartan (VAL), atorvastatin (ATR), bisoprolol (BSL), amlodipine (AML) and carvedilol (CVL); alongside with the nutraceutical vincamine (VIC) is essential for sustainable pharmaceutical analysis. This study explores the application of Micellar Electro Kinetic Chromatography (MEKC) and High-Performance Liquid Chromatography (HPLC) for this purpose. In MEKC method, the separation was done using fused silica capillary (41.5 cm × 50 µm id) and a back ground electrolyte consisting of 50 mM borate buffer (pH 9) containing 50 mM sodium lauryl sulphate (SLS) and 10% organic modifier (Acetonitrile). In HPLC method, separation was performed on a ZORBAX Extend-C18 (4.6 × 250 mm, 5 µm) column, using a gradient mobile phase consisting of 50 mM phosphate buffer pH 3 and methanol. Both methods attained good linearity (r ≥ 0.9996) with low values of LOD and LOQ. Both methods were successfully applied in the determination of co-administered single, binary and ternary dosage form of the studied drugs. Moreover, application of various combinations of co-administered dosage forms was achieved in rat plasma, confirming the applicability of these methods in different matrices. The use of micellar solutions in MEKC enhances separation efficiency while reducing the need for organic solvents, aligning with green chemistry principles. HPLC methods were optimized using environmentally benign solvents, ensuring reduced toxicity and waste production. The methodologies were evaluated through green, white, and blue metrics to ensure comprehensive sustainability, considering ecological impact, safety, and practical efficiency. These methods were not only cost-effective and time-saving but achieved high efficiency, sensitivity, and reproducibility making them ideal for routine use in pharmaceutical analysis.

Synthesis of magnetically separable mixed metal oxide nanocomposite (Cu/CoFe2O4) for Huisgen 1,3-dipolar cycloaddition

A magnetically recoverable mixed metal oxide nanocomposite (Cu/CoFe2O4) was synthesized and employed for the Huisgen 1,3-dipolar cycloaddition reaction. Functionally diverse 1,4-disubstituted-1,2,3-triazoles synthesized from aryl halide, sodium azide and terminal alkyne in ethanol. The physico-chemical study of the catalyst was characterized by XRD, SEM, TEM, EDS, TGA, XPS and VSM. Use of sustainable catalytic system, simple procedure, mild reaction conditions, easy work-up, short reaction times, high product yields and use of a benign solvent are remarkable features of the present protocol. The catalyst nontoxic nature and easy recovery and reusability over several reaction cycles makes this protocol more competent.Graphical

Brønsted acid catalyzed green and efficient construction of α-amino peroxides from 3-hydroxyisoindolinones and hydroperoxides

A Brønsted acid-catalyzed peroxidation of 3-hydroxyisoindolinones with hydroperoxides has been established for the first time, which constructs α-amino peroxides bearing a tetrasubstituted stereocenter in good to high yields and enantioselectivities. The transformation uses of environmentally benign solvents, and features operational simplicity, and high atom economy. The synthetic utility was demonstrated with the gram-scale reactions and further transformations of the products. Notably, preliminary bioactivity studies reveal that these valuable α-amino peroxides show potential anticancer activity.

High‐Throughput Production of Gelatin‐Based Touch‐Spun Nanofiber for Biomedical Applications

Nanofiber production techniques have become increasingly important due to their wide range of applications. However, the complex design of the setup and difficulty in scaling up to high production rate have limited the industrial applicability of some of the conventional fiber generation techniques such as electrospinning. Herein, the touch spinning method is scaled up for nanofiber production using a simple rotating drawing setup with polymers that are relevant for biomedical applications such as polyethylene oxide and gelatin. The process is amenable to use of benign solvent such as water and production of a wide variety of submicron‐scale gelatin‐based nanofibers at a high throughput (≈2.45 g hr−1 with the single channel flow), which is an order of magnitude higher than those produced by other fiber generation methods is shown. The parametric study indicates that the fiber production process can be tuned at a desired rate without sacrificing the fiber quality by simply altering the number of drawing rods, the size of the rotating disk, and the number of solution flow supply channels. The utility of this technique for different biomedical applications such as cell culture and air filtration applications is also demonstrated.

Electrospun poly(ε-caprolactone)/poly(glycerol sebacate) aligned fibers fabricated with benign solvents for tendon tissue engineering.

The electrospinning technique is a commonly employed approach to fabricate fibers intended for various tissue engineering applications. The aim of this study is to develop a novel strategy for tendon repair through the use of aligned poly(ε-caprolactone) (PCL) and poly(glycerol sebacate) (PGS) fibers fabricated in benign solvents, and further explore the potential application of PGS in tendon tissue engineering (TTE). The fibers were characterized for their morphological and physicochemical properties; amniotic epithelial stem cells (AECs) were used to assess the fibers teno-inductive and immunomodulatory potential due to their ability to teno-differentiate undergoing first a stepwise epithelial to mesenchymal transition, and due to their documented therapeutic role in tendon regeneration. The addition of PGS to PCL improved the spinnability of the polymer solution, as well as the uniformity and directionality of the so-obtained fibers. The mechanical properties were in the range of most TTE applications, specifically in the case of PCL/PGS 4:1 and 2:1 ratios. Compared to PCL alone, the same ratios also allowed a better AECs infiltration and growth over 7 days of culture, and triggered the activation of tendon-related genes (SCX, COL1, TNMD) and the expression of tenomodulin (TNMD) at the protein level. Concerning the immunomodulatory properties, both PCL and PCL/PGS fibers negatively affected the immunomodulatory profile of AECs, up-regulating both anti-inflammatory (IL-10) and pro-inflammatory (IL-12) cytokines over 7 days of culture. Overall, PCL/PGS 2:1 fibers fabricated with benign solvents proved to be the most suitable composition for TTE application based on their topographical cues, mechanical properties, biocompatibility, and teno-inductive properties.

Systematic solvent selection enables the fractionation of wet microalgal biomass

Wet microalgal biomass was recently proposed as a feedstock to circumvent the energy-intensive drying step in biorefineries. However, solvents commonly applied to extract valuable target compounds from dried biomass are usually less effective when applied on wet biomass. In the present study, we investigated the potential of systematic solvent selection to increase pigment and lipid yields for the extraction of wet Phaeodactylum tricornutum biomass. The solvent selection was guided by a large-scale computational screening approach. Experiments revealed, that 2-butanol – a non-toxic, partially water-miscible solvent – extracted 99.4 wt% of lipids and 82.6 wt% of carotenoids from wet biomass. By using only 2-butanol and water as benign solvents, we developed a biorefinery approach that effectively fractionates wet microalgal biomass under ambient conditions into proteins, carbohydrates, carotenoids and lipids without the need for energy-intensive biomass drying.

Glucose-Water Synergy: An Organocatalytic System Driven synthesis of Benzimidazolo[2,3-b]quinazolinone and Benzothiazolo[2,3-b]quinazolinone Derivatives

Introduction: A simple and efficient one-pot synthesis of quinazolinone derivatives has been developed via a multicomponent reaction (MCR) involving the condensation of dimedone, benzaldehyde, and 2-aminobenzimidazole/2-aminobenzothiazole. Method: In this work, glucose water is used as a green, reusable, environmentally benign organocatalytic solvent system to synthesize desired products. Result: The main benefits of this one-pot method include its excellent yields, less time, cost-effectiveness, atom economy, environment benign, and easy workup. Conclusion: In conclusion, we successfully developed a green protocol for the environmentally benign synthesis of benzimidazo/benzothiazolo quinazolinones using glucose water as an organocatalytic medium.

Approaching 20% Efficiency in Ortho-Xylene Processed Organic Solar Cells by a Benzo[a]phenazine-Core-Based 3D Network Acceptor with Large Electronic Coupling and Long Exciton Diffusion Length.

High-performance organic solar cells often rely on halogen-containing solvents, which restrict the photovoltaic industry. Therefore, it is imperative to develop efficient organic photovoltaic materials compatible with halogen-free solvents. Herein, a series of benzo[a]phenazine (BP)-core-based small-molecule acceptors (SMAs) achieved through an isomerization chlorination strategy is presented, comprising unchlorinated NA1, 10-chlorine substituted NA2, 8-chlorine substituted NA3, and 7-chlorine substituted NA4. Theoretical simulations highlight NA3's superior orbit overlap length and tight molecular packing, attributed to interactions between the end group and BP unit. Furthermore, NA3 demonstrates dense 3D network structures and a record electronic coupling of 104.5 meV. These characteristics empower the ortho-xylene (o-XY) processed PM6:NA3 device with superior power conversion efficiency (PCE) of 18.94%, surpassing PM6:NA1 (15.34%), PM6:NA2 (7.18%), and PM6:NA4 (16.02%). Notably, the significantly lower PCE in the PM6:NA2 device is attributed to excessive self-aggregation characteristics of NA2 in o-XY. Importantly, the incorporation of D18-Cl into the PM6:NA3 binary blend enhances crystallographic ordering and increases the exciton diffusion length of the donor phase, resulting in a ternary device efficiency of 19.75% (certified as 19.39%). These findings underscore the significance of incorporating new electron-deficient units in the design of efficient SMAs tailored for environmentally benign solvent processing of OSCs.

Synthesis of branched and linear aryl allylic alcohols: C[sbnd]H bond allylation of 2-aryl-3H-indoles with vinyl cyclic carbonates

Presented herein is an effective synthesis of branched and linear allyl arenes based on the reactions of 2-aryl-3H-indoles with 5-methylene-1,3-dioxan-2-one or 4-vinyl-1,3-dioxolan-2-one. Mechanistically, the reactions are initiated by Rh(III)-catalyzed aryl C(sp2)–H bond activation/cyclometallation followed by vinyl coordination/migratory insertion and β–O elimination through release of CO2 as the only by-product. By using this newly developed protocol, a group of 2-aryl-3H-indole derivatives bearing the substructure of either branched or linear allylic alcohol were obtained in good efficiency. Notably, the linear allylic alcohols were obtained with excellent E/Z selectivity when unsubstituted vinyl-1,3-dioxolan-2-one was used as the allyl surrogate. With advantages such as easily available starting materials, mild and redox-neutral reaction conditions, good compatibility with a broad range of functional groups, benign solvent and divergent products, this protocol is expected to be used in the synthesis of indole-based functional molecules.

Transformation of D-xylose into furfuryl alcohol via an efficient chemobiological approach in a benign deep eutectic solvent lactic acid:betaine-water reaction system

Biobased furfuryl alcohol (FOL) was a common building block for the production of resins, lubricants, plasticizers, organic compounds and value-added intermediates. For the effectual efficient production of FOL, a combination of chemocatalytic and biocatalytic approach was built for the transformation of D-xylose to FOL in a deep eutectic solvent (DES) lactic acid:betaine-H2O (LA:Bet-H2O) system. The furfural (FAL) yield of LA:Bet-H2O (10:90, vol/vol) for 30 min at 180 °C reached 81.6 % using D-xylose (150 g/L) as substrate in a high-pressure reactor. Using glucose as co-substrate, E. coli HMFOMUT whole cell could transform the formed FAL (125 mM) into FOL (96.8 % yield) in a conical flask at 37 °C and pH 7.0 in this LA:Bet-H2O (5:95, vol/vol) medium. In 50 mL LA:Bet-H2O, HMFOMUT cells effectually convert D-xylose-derived FAL to FOL, and 0.75 g of D-xylose formed FOL (0.384 g, 78.2 % yield) and furoic acid (FA) (0.019 g, 3.4 % yield). In the present study, a one-pot tandem method was used to effectually catalyze the synthesis of FOL from D-xylose using an effectual combination of chemocatalysis with LA:Bet and biocatalysis with E. coli HMFOMUT in a reactor. It affords a new idea for the effectual use of biomass resources to synthesize high value-added compounds, and also renders a mild, green, environmentally friendly and sustainable strategy for the manufacturing of bio-based platform derivatives.

Aggregation in Deep Eutectic Solvents (DESs): Formation of Polar DES-in-Nonpolar DES Microemulsions.

The versatility of environmentally benign and inexpensive deep eutectic solvents (DESs) lies in their widely varying physicochemical properties. Depending on its constituents, a DES may be highly polar or nonpolar in nature. This offers an enticing possibility of formation of novel nonaqueous microemulsions (MEs). Evidence of the presence of polar DES-in-nonpolar DES MEs is presented with reline (formed by mixing choline chloride and urea in 1 : 2 mol ratio) as the polar DES forming the ME pools, Thy : DA [formed by mixing thymol (Thy) and n-decanoic acid (DA) in 1 : 1 mol ratio] nonpolar DES as the bulk oil phase and nonionic surfactant Brij-35 as the emulsifying agent. While only sparingly miscible in Thy : DA, as high as 2.5 M reline can be solubilized in this DES in the presence of 100 mM Brij-35; reline loading (w Rel = [reline]/[Brij-35]) as high as 25 can be achieved. The ternary phase diagram of the Thy : DA/Brij-35/reline system reveals a clear and transparent single-phase region where MEs may be forming. Dynamic light scattering confirms the presence of MEs of 2-10 nm size. Even as up to 2.5 M (ca. 0.35 mole fraction) reline, whose dynamic viscosity (η) and electrical conductivity (κ) are very high, is added to 100 mM Brij-35 solution of Thy : DA, the η and κ values of the solution increase insignificantly, thus conforming to the formation of MEs in the solution. Fourier transform infrared (FTIR) absorbance spectra and fluorescence probe responses further indicate that reline is not dispersed in the medium but rather forms polar pools of the MEs. These novel nonaqueous polar DES-in-nonpolar DES MEs will not only expand the application potential of DESs but also offer a new class of organized media with widespread potential.

Sequential‐dip‐coating processed mixed organic and inorganic perovskite film from halide‐free lead precursor for efficient perovskite solar cells

AbstractA novel all‐sequential‐dip‐coated (SDC) deposited FA1MA1−yPbI3−xBrx perovskite films have been synthesized from an aqueous non‐halide lead precursor towards an environmentally benign, cost‐effective, and efficient approach for high‐performance perovskite solar cells (PrSCs). The mixed‐cationic FA1MA1−yPbI3−xBrx perovskite layers ensure the fractional incorporation of Br into the perovskite crystal lattice. The insertion of Br contents was regulated by modulating the FABr concentration into the FABr/MAI mixed‐cationic precursor solution. The incorporation of minor FABr into MAI helps to improve the surface coverage and crystallinity of the synthesized per‐ovskite layer in contrast to the other perovskite films prepared with higher FABr content under the same environment. The PrSCs with these FA1MA1−yPbI3−xBrx perovskite layers displayed good de‐vice performances and stability with a PCE of 11.1%. These outcomes reveal that the synthesis of FA1MA1−yPbI3−xBrx perovskite films with the SDC approach is more efficient because of the use of environmentally benign solvents for synthesizing lead and perovskite layers.

High-Performance Dopamine-Based Supramolecular Bio-Adhesives.

The need for wound closure or surgical procedures has been commonly met by the application of sutures. Unfortunately, these are often invasive or subject to contamination. Alternative solutions are offered by surgical adhesives that can be applied and set without major disruption; a new class of supramolecular-based adhesives provides potential solutions to some of these challenges. In this study, a series of polymers utilizing dopamine as a self-assembling unit are synthesized. It is found that these motifs act as extremely effective adhesives, with control over the mechanical strength of the adhesion and materials' tensile properties enabled by changing monomer feed ratios and levels of cross-linking. These materials significantly outperform commercially available bio-adhesives, showing yield strengths after adhesion at least two times higher than that of BioGlue and Tisseel, as well as the ability to re-adhere with significant recovery of adhesion strength. Promisingly, the materials are shown to be non-cytotoxic, with cell viability > 90%, and able to perform in aqueous environments without significant loss in strength. Finally, the removal of the materials, is possible using benign organic solvents such as ethanol. These properties all demonstrate the effectiveness of the materials as potential bio-adhesives, with potential advantages for use in surgery.

Molecular Dynamics Study of the Green Solvent Polyethylene Glycol with Water Impurities.

Polyethylene glycol (PEG) is one of the environmentally benign solvent options for green chemistry. It readily absorbs water when exposed to the atmosphere. The Molecular Dynamics (MD) simulations of PEG200, a commercial mixture of low molecular weight polyethyelene glycol oligomers, as well as di-, tetra-, and hexaethylene glycol are presented to study the effect of added water impurities up to a weight fraction of 0.020, which covers the typical range of water impurities due to water absorption from the atmosphere. Each system was simulated a total of four times using different combinations of two force fields for the water (SPC/E and TIP4P/2005) and two force fields for the PEG and oligomer (OPLS-AA and modified OPLS-AA). The observed trends in the effects of water addition were qualitatively quite robust with respect to these force field combinations and showed that the water does not aggregate but forms hydrogen bonds at most between two water molecules. In general, the added water causes overall either no or very small and nuanced effects in the simulation results. Specifically, the obtained water RDFs are mostly identical regardless of the water content. The added water reduces oligomer hydrogen bonding interactions overall as it competes and forms hydrogen bonds with the oligomers. The loss of intramolecular oligomer hydrogen bonding is in part compensated by oligomers switching from inter- to intramolecular hydrogen bonding. The interplay of the competing hydrogen bonding interactions leads to the presence of shallow extrema with respect to the water weight fraction dependencies for densities, viscosities, and self-diffusion coefficients, in contrast to experimental measurements, which show monotonous dependencies. However, these trends are very small in magnitude and thus confirm the experimentally observed insensitivity of these physical properties to the presence of water impurities.

High Modulus, Strut-like poly(ether ether ketone) Aerogels Produced from a Benign Solvent.

Poly(ether ether ketone) (PEEK) was found to form gels in the benign solvent 1,3-diphenylacetone (DPA). Gelation of PEEK in DPA was found to form an interconnected, strut-like morphology composed of polymer axialites. To our knowledge, this is the first report of a strut-like morphology for PEEK aerogels. PEEK/DPA gels were prepared by first dissolving PEEK in DPA at 320 °C. Upon cooling to 50 °C, PEEK crystallizes and forms a gel in DPA. The PEEK/DPA phase diagram indicated that phase separation occurs by solid-liquid phase separation, implying that DPA is a good solvent for PEEK. The Flory-Huggins interaction parameter, calculated as χ12 = 0.093 for the PEEK/DPA system, confirmed that DPA is a good solvent for PEEK. PEEK aerogels were prepared by solvent exchanging DPA to water then freeze-drying. PEEK aerogels were found to have densities between 0.09 and 0.25 g/cm3, porosities between 80 and 93%, and surface areas between 200 and 225 m2/g, depending on the initial gel concentration. Using nitrogen adsorption analyses, PEEK aerogels were found to be mesoporous adsorbents, with mesopore sizes of about 8 nm, which formed between stacks of platelike crystalline lamellae. Scanning electron microscopy and X-ray scattering were utilized to elucidate the hierarchical structure of the PEEK aerogels. Morphological analysis found that the PEEK/DPA gels were composed of a highly nucleated network of PEEK axialites (i.e., aggregates of stacked crystalline lamellae). The highly connected axialite network imparted robust mechanical properties on PEEK aerogels, which were found to densify less upon freeze-drying than globular PEEK aerogel counterparts gelled from dichloroacetic acid (DCA) or 4-chlorphenol (4CP). PEEK aerogels formed from DPA were also found to have a modulus-density scaling that was far more efficient in supporting loads than the poorly connected aerogels formed from PEEK/DCA or PEEK/4CP solutions. The strut-like morphology in these new PEEK aerogels also significantly improved the modulus to a degree that is comparable to high-performance crosslinked aerogels based on polyimide and polyurea of comparable densities.

The Study of Molecules and Processes in Solution: An Overview of Questions, Approaches and Applications

Many industrial processes, several natural processes involving non-living matter, and all the processes occurring within living organisms take place in solution. This means that the molecules playing active roles in the processes are present within another medium, called solvent. The solute molecules are surrounded by solvent molecules and interact with them. Understanding the nature and strength of these interactions, and the way in which they modify the properties of the solute molecules, is important for a better understanding of the chemical processes occurring in solution, including possible roles of the solvent in those processes. Computational studies can provide a wealth of information on solute–solvent interactions and their effects. Two major models have been developed to this purpose: a model viewing the solvent as a polarisable continuum surrounding the solute molecule, and a model considering a certain number of explicit solvent molecules around a solute molecule. Each of them has its advantages and challenges, and one selects the model that is more suitable for the type of information desired for the specific system under consideration. These studies are important in many areas of chemistry research, from the investigation of the processes occurring within a living organism to drug design and to the design of environmentally benign solvents meant to replace less benign ones in the chemical industry, as envisaged by the green chemistry principles. The paper presents a quick overview of the modelling approaches and an overview of concrete studies, with reference to selected crucial investigation themes.

Electrospinning-netting of spider-inspired polycaprolactone/collagen nanofiber-nets incorporated with Propolis extract for enhanced wound healing applications

Nanofibers hold significant promise for wound healing applications, but their potential is limited by their large diameter. To overcome this limitation, the development of nanofibrous systems with refined nanonets (approximately 20 nm in diameter) represents a notable improvement. In this study, a composite of polycaprolactone/collagen (PCLC) nano-fiber/nets (NFNs) was fabricated using benign solvents (acetic acid and formic acid) via the electro-spinning/netting (ESN) technique, harnessing the regenerative potential of collagen as a biological macromolecule. Additionally, to enhance the natural attributes of the NFNs structure, Propolis extract, renowned for its wound healing properties, was incorporated. Five ESN solutions were prepared: PCL, PCLC, PCLC/Pro 5 %, PCLC/Pro 10 %, and PCLC/Pro 15 %. NaCl salt was introduced into all ESN solutions to improve nanonets formation. FE-SEM imaging demonstrated successful nano-net formation in all ESN solutions except for the PCL formulation. The fabricated scaffolds exhibited spider-like nanonets with the addition of collagen and further enhanced nano-net formation with Propolis incorporation. Trunk nanofibers showed filamentous structures without any beads, with an average diameter of 164–728 nm, while the diameter of branched fibers (nanonets) was approximately 20 nm. WVTR values of the NFNs were comparable to commercial dressings such as Tegaderm. The results also demonstrated the potent cytoprotective effects of Propolis-loaded NFNs in a dose-dependent manner. Furthermore, the viability of HFF-2 cells after 72 h of culture on PCLC NFNs significantly increased compared to PCL nanofibers. The highest cell viability was observed in PCLC/Pro 15 % nanofibers after 24, 48, and 72 h of cell culture, indicating the proliferative effect of Propolis extract in nanoformulated form. Additionally, the scaffolds exhibited a hemocompatibility of <3 %, further highlighting their potential in wound healing therapeutics.

A Comparative Study on the Choice of the Support in the Elaboration of Photocatalysts for the Photooxidation of Benzyl Alcohol under Mild Conditions

In the quest to combat global warming, traditional thermal chemistry processes are giving way to selective photocatalysis, an eco-friendly approach that operates under milder conditions, using benign solvents like water. Benzaldehyde, a versatile compound with applications spanning agroindustry, pharmaceuticals, and cosmetics, serves as a fundamental building block for various fine chemicals. This study aims at enhancing benzaldehyde production sustainability by utilizing photooxidation of benzyl alcohol. Gold nanoparticle-based catalysts are renowned for their exceptional efficiency in oxidizing bio-based molecules. In this research, Au nanoparticles were anchored onto three distinct supports: TiO2, ZrO2, and graphitic carbon nitride (g-C3N4). The objective was to investigate the influence of the support material on the selective photocatalysis of benzyl alcohol. In the preparation of g-C3N4, three different precursors—melamine, urea, and a 50:50 mixture of both—were chosen to analyze their impact on catalyst performance. After 4 h of irradiation at 365 nm, operating under acidic conditions (pH = 2), the Au photocatalyst on graphitic carbon nitride support synthesized using urea precursor (Au@g-C3N4(urea)) displayed the optimal balance between conversion (75%) and selectivity (85%). This formulation outperformed the benchmark Au@TiO2, which achieved a similar conversion rate (80%) but exhibited lower selectivity (55%).

Free fatty acid-rich oils as potential benign organic solvent for dyes removal in solvent extraction system

The extensive use of water in the textile industry results in the production of significant volumes of effluent-containing dyes, posing both economic and environmental concerns due to their harmful impact. Hence, the removal of dye from wastewater is very important for environmental protection and other aspects of well-being. Solvent extraction emerges as one of the promising methods used for dye removal. Nevertheless, the conventional organic phase formulation comprises an extractant, diluent, and modifier sourced from petroleum-based compounds, leading to environmental degradation. Thus, in this study, free fatty acid (FFA)-rich oils, i.e., Palm Kernel Fatty Acid Distillate (PKFAD) and Jatropha Oil (JO), were proposed as the green and benign organic solvent for the extraction of Crystal Violet-(CV) and Methylene Blue-(MB) from an aqueous solution. These FFA-rich oils act as reactive diluents due to the presence of FFA, which acts as an acidic extractant. Therefore, a new formulation of green sole-organic solvent without the addition of extractant and modifier was applied in this system. This study aimed to determine the best pH equilibrium for extracting CV and MB from different FFA-rich oils, i.e., PKFAD and JO. The results indicated the optimum extraction of CV is 95% at an equilibrium pH of 2.7 and 6.3 for PKFAD and JO, respectively. In comparison, the extraction of MB achieved 88% (pH 5.5) and 86% (pH 8.5) for PKFAD and JO, respectively. The stripping obtained a high removal percentage for both CV and MB, with 93% and 99%, respectively.