Organic Phase Research Articles

Synthesis, Characterization, Bioavailability and Antimicrobial Studies of Cefuroxime-Based Organic Salts and Ionic Liquids

Low oral bioavailability is a common feature in most drugs, including antibiotics, due to low solubility in physiological media and inadequate cell permeability, which may limit their efficacy or restrict their administration in a clinical setting. Cefuroxime is usually administered in its prodrug form, cefuroxime axetil. However, its preparation requires further reaction steps and additional metabolic pathways to be converted into its active form. The combination of Active Pharmaceutical Ingredients (APIs) with biocompatible organic molecules as salts is a viable and documented method to improve the solubility and permeability of a drug. Herein, the preparations of five organic salts of cefuroxime as an anion with enhanced physicochemical characteristics have been reported. These were prepared via buffer-assisted neutralization methodology with pyridinium and imidazolium cations in quantitative yields and presented as solids at room temperature. Cell viability studies on 3T3 cells showed that only the cefuroxime salts combined with longer alkyl chain cations possess higher cytotoxicity than the original drug, and while most salts lost in vitro antibacterial activity against E. coli, P. aeruginosa and B. subtilis, one compound, [PyC10Py][CFX]2, retained the activity. Cefuroxime organic salts have a water solubility 8-to-200-times greater than the original drug at 37 °C. The most soluble compounds have a very low octanol-water partition, similar to cefuroxime, while more lipophilic salts partition predominantly to the organic phase.

Highly enhanced fluoride removal from aqueous systems via solvent extraction utilizing trialkyl phosphine oxide as an efficient extractant

Solvent extraction (SX) has been recognized as an efficient approach for the large-scale removal of impurities, demonstrating considerable potential for fluoride extraction in industrial applications. However, existing fluoride extraction methods typically require the incorporation of additives to form complexes with fluoride for its removal. Due to the excessive additive requirements for efficient fluoride removal, these methods inevitably result in secondary contamination of feed solution, necessitating additional purification efforts to remove them. In this study, four extractants (trioctyl amine, tributyl phosphate, trioctyl phosphate, and trialkyl phosphine oxide (TRPO)) were investigated for fluoride removal via hydrogen bonding with hydrofluoric acid (HF). Various parameters, including the concentrations of extractants and stripping agents, pH values, extraction time, and temperature were initially optimized. It was found that TRPO exhibits the highest extraction efficiency for HF, with a single-stage extraction rate exceeding 70 %. Complete fluoride removal (> 99.9 %) was achieved through a consecutive four-stage extraction process. Further experiments, including maximum loading and slope analysis, combined with FT-IR and 19F NMR characterization, and DFT calculations elucidate the mechanism of the extraction. The transfer of HF into the organic phase is accomplished by the formation of a 1:1 hydrogen-bonded complex with TRPO. The loaded fluoride in the organic phase can be easily stripped by a base to get a fluoride salt. This study paves the way for the construction of novel SX systems to remove fluoride as HF.

Development of polarizable and hydration-focused water models for the Martini 3 force field

Coarse-grained simulations have been increasingly employed in many fields of molecular chemistry. These models enable the evaluation of complex molecular structures by simplifying their description compared to all-atoms models. Specifically, the Martini 3 force field has been developed to describe biomolecular structures such as proteins, lipids, and carbohydrates. Their “building block” approach has been successfully used in modeling complex systems ranging from carbohydrate solutions, biological membranes, and even deep eutectic solvents. However, one main issue arises when considering interfacial systems: water is represented as a single particle with no effect of electrostatic interactions. In this work, we developed a polarizable water model for the Martini 3 force field, introducing charged particles to model the electrostatic interactions present in water systems accurately. Gaussian Processes were trained with simulation data for both bulk water and cross-interaction parameterization to consistently explore the parameter space and fine-tune our model to the target properties. The developed model showed good performance in reproducing the density and dielectric constant of bulk water. Regarding cross-interaction with other beads, two different sets of parameters were developed. The first, called the polarizable model, is parameterized to reproduce the hydration free energies of the original Martini 3 organic beads. This allows for a good description of free energies of transfer between water and organic phases, the main target property for the Martini 3 force field. The second, called the polarizable-hydration model, is parameterized to match the experimental hydration free energy of selected molecules. This allows for more accurate evaluation of hydration properties, which can be useful for water solutions. In particular, we show that the partitioning and interfacial behavior of nonionic surfactants is improved by the polarizable-hydration model when compared to the standard Martini 3 water model.

Chemical and mechanistic modelling of green solvent extraction of metallic species with 4-acylpyrazolones

Solvent extraction chemistry of metals needs the use of suitable organic ligands like 4-acylpyrazolones to coordinate the studied cation, to make it soluble in an organic phase and then allow its phase transfer from the aqueous phase. The competitive solvent extraction test of almost 25 metal ions by one powerful ligand, i.e. 3-methyl-1-phenyl-4-(4-trifluoromethylbenzoyl)-pyrazol-5-one diluted in one ionic liquid ([C1Cnim+][Tf2N−]) has been conducted to get a snapshot of its efficacy. Effect of diluents on the liquid–liquid extraction of 4f-ions with a series of chelating ligands of 4-acylpyrazolones family (∼5) is presented comparing ionic liquids and typical organic diluents: 14 in number. In addition, the solvent extraction of 12 refractory metals with a series of chelating extractants is investigated in five diluents: four 4-acylpyrazolones with different radicals. The solvent extraction stoichiometry of MoO42− and Zr4+ is studied in detail using molecular and ionic diluent for comparative purposes through slope analysis method. Ethylene glycol is used to develop a non-aqueous process for Gd3+ switchable extraction, i.e. boost of two immiscible organic phases. Furthermore, EPR, NMR, IR and DTA-TG-MS spectroscopies have been used to study the extracted d- and f-species in the obtained organic extracts in ionic liquid solutions.

Modulating the carbon chain length of organic phosphine for the selective Au(I) recovery from a copper-ammonia-thiosulfate leaching solution

The selective recovery of gold ions from gold leaching solutions limits the industrial application of the copper-ammonia (Cu2+–NH3)-thiosulfate system. Here, the influence of the carbon chain length of organic phosphines on the selective recovery of gold ions was studied, and an extractant (trihexylphosphine, THP) that is suitable for the selective recovery of gold ions from a Cu2+–NH3-thiosulfate leaching solution was screened. The selectivity of organic phosphines with different carbon chain lengths for gold ions was C8 = C6 > C4 > C3 > C2, and when the number of carbon atoms in a single carbon chain was at least six, the selective recovery of gold ions from the Cu2+–NH3-thiosulfate solution was realized. THP completely recovered low concentration gold ions (6.73 mg/L) in the Cu2+–NH3-thiosulfate gold leaching solution regardless of the pH. The mechanism of gold ion extraction into the organic phase mainly involved ligand exchange between THP and [Au(S2O3)2]3−. Job’s method and density functional theory calculations confirmed that the composition ratio of the complex formed by THP and Au was 2:1 at the practical and theoretical levels, respectively. Finally, Multiwfn and VMD were used to visually predict the possible reaction sites in THP. This study provides an exact method for the selective recovery of gold ions from thiosulfate-based gold leaching solutions, which will promote the development of thiosulfate-based gold leaching systems

Self-assembled nanoflower-mediated interfacial polymerization through tunable intra- and inter-layer channels to boost total heat exchange performance

Total heat exchange membranes (THEMs) are vital for minimizing energy consumption and enhancing indoor air quality in energy recovery ventilation (ERV) systems. Manipulating the surface morphology of polyamide (PA) membranes via nanofiller-mediated interfacial polymerization is key to advancing total heat recovery performance. This study presented the fabrication of PA thin-film nanocomposite (TFN) membranes by integrating self-assembled poly(amic acid-imide) nanoflowers (P(AA-I)-NFs) with intertwined nanosheets into the organic phase. This facile approach effectively eliminated nonselective interphase voids and defects, owing to the superior polymer affinity of the organic nanoflowers. The finely tuned intra- and inter-layer channels within P(AA-I)-NFs significantly impacted monomer mass transfer, facilitated the shuttle effect, expanded the interfacial polymerization zone, and led to the formation of a rougher, thicker PA layer with enhanced surface area. The optimized P(AA-I)-NFs/PA TFN membranes exhibited outstanding performance, including CO₂ permeability of 0.51 GPU, water vapor permeability of 656.59 GPU, and an enthalpy exchange efficiency of 71.47 %, surpassing the trade-off limitations typically observed in commercial and other advanced THEMs. These findings underscored the potential of P(AA-I)-NFs-mediated TFN membranes as highly competitive candidates for next-generation ERV systems.

A comprehensive undergraduate experiment: preparation and chromatographic evaluation of a core-shell stationary phase based on a covalent organic framework

Continuously promoting new curriculum standards is a key aim of the Ministry of Education of China. With this in mind, this paper introduces a comprehensive teaching experiment for undergraduate instrumental analysis courses that aims to improve students' material-preparation and instrumental-analysis skills through practice. Herein, a covalent organic framework-based core-shell stationary phase material (SiO2@COFTTA-DHTA) is prepared via a one-pot method and characterized in detail, after which its chromatographic properties are evaluated by high performance liquid chromatography (HPLC). The experimental process includes material synthesis and characterization, as well as studying the chromatographic-retention behavior and chromatographic-separation performance of the material. By the combining theoretical science and experimental teaching, this experiment not only deepens students' understanding of the properties of functional materials and their applications, but also improves their experimental-design and critical-thinking skills. This experiment not only cultivates students' interests in scientific research, but also exercises their experimental, operational, innovative-thinking, and practical abilities, while concurrently enhancing their sense of social responsibility and historical mission, thereby delivering the all-round educational goals of experimental teaching.

Investigations on the effect of arsenic and phosphorus atomic exchange on the origin of crystal potential fluctuations in InAsP/InP epilayers

The study investigates the anion exchange mechanism between the ad-atoms of arsenic and phosphorus followed by their inter-diffusion processes, in InAsP/InP hetero-structures grown by metal organic vapor phase epitaxy technique. The energetics and kinetics of the ad-atoms like arsenic and phosphorus are governed by the growth conditions. It has been found that the percolation of arsenic and phosphorus in the epilayer depends on various factors, such as gas-phase diffusion coefficients, surface reaction rates, misfit strain energy, bond energy, segregations, and the presence of defects and dislocations. Effects of anion exchange mechanisms on generating local crystal potential states that originated due to the local crystal bonding environment are further investigated. The magnitude of these local potential states strongly depends on the strain states associated with the layer thickness. If the difference between the potential minima is small (< 25 meV), it leads to distinct “S” shaped temperature-dependent luminescence/absorption spectra. In contrast, a large difference gives rise to two distinctive luminescence/absorption peaks. Thus, by controlling the strain states associated with the energetics and kinetics of ad-atoms like arsenic/phosphorus and layer thickness, such “S” shaped behavior can be controlled.

Streamlined fractionation for recovery of high-yield xylo-oligosaccharides, pure lignin and ethanol from poplar using short-chain organic acid/pentanol biphasic system

Biphasic pretreatment offers a sustainable method by integrating the fractionation of hemicellulose, lignin, and cellulose into a single process, thereby enhancing biomass resource utilization while reducing environmental impact. However, this process faces the challenge of diverse hemicellulose products with low added value. This study employed organic acid-catalyzed water/pentanol biphasic pretreatment to selectively convert hemicellulose into xylooligosaccharides (XOS), while simultaneously separating lignin and cellulose. Both the organic acids and pentanol used are biodegradable and compatible. The lactic acid (LA)/pentanol biphasic system was particularly effective for XOS production and lignin removal, attributed to the high acidity of LA and its relatively low partition coefficients in the water/pentanol system, crucial factors influencing hemicellulose and lignin separation efficiency. The XOS yields reached 46.9 %, while the lignin removal rate was 74.6 %. Additionally, LA/pentanol pretreatment significantly enhanced cellulose digestibility, demonstrated by an ethanol production of 54.1 g/L during simultaneous saccharification fermentation at 15 % solids loading. The recovered lignin from the organic phase retained the structural characteristics of native lignin. It also had a low molecular weight and abundant phenolic hydroxyl groups, indicating its suitability for further valorization. Pentanol maintained its performance after four cycles of reuse, demonstrating the stability and reusability of the solvent system. This study highlighted the potential of the LA/pentanol biphasic system for simultaneous hemicellulose conversion and lignin isolation, offering a simplified and sustainable one-step valorization route for biomass.

Lipophilic EDTA-based ligands in different diluents for the extraction of rare earths: Preliminary results with Nd(III), Dy(III) and Pr(III) in chloride and nitrate media

A separation method for the recovery of neodymium(III) from two different media, chloride and nitrate, by implementing solvent extraction technique with a novel lipophilic diamide derivative of ethylenediamine tetraacetic acid (EDTA), namely 2,2’-N,N′-didecyl-dioxo-N,N′,N″,N″’-tetraazatetratriacontane-N″,N″’-diyl diacetic acid (H2E4C10), has been investigated. Initial screening results demonstrated acceptable solubility (ca. 15 mM) of the diamide in 1,3-diisopropylbenzene (DiPB) and in a 93:7 v:v n-dodecane:n-octanol mixture (DOm) as non-polar diluents. Further investigations aiming at determining operational parameters associated with the befitted extractant systems were conducted at pH ranging from 2 to 4 in chloride and nitrate media. A pH-dependent performance of the proposed systems revealed loading capacity peaking at pH = 3 with the respective values of 1.7 and 2.0 g L−1 in nitrate and chloride media. The extraction efficiency, the distribution coefficients, and the separation factor (E%,D and SF, respectively) were determined for an equimolar mixture of neodymium and two other potential competitive lanthanides, namely dysprosium and praseodymium. The best selectivity was observed in the chloride medium at pH = 4 yielding SFNd/Pr = 1.48 and SFNd/Dy = 2.03. Neodymium-to-extractant stoichiometry was evidenced in chloroform to be 1:1 H2E:Nd at pH = 2. Thermodynamic constants related to the considered extraction equilibrium have been determined by using the Van't Hoff relation and the slope analysis method. It appeared within the selected pH-range that the mechanism of the Nd3+ transfer was strongly influenced by the nature of the diluent. This was illustrated by the enthalpy-driven transfer when Nd3+ was extracted with the H2E-4C10-Dom system (aliphatic diluent) while the transfer became entropy-driven when the extraction was performed with the H2E-4C10-DiPB system (aromatic diluent). The complexation of Nd3+ involved mainly the participation of both the amide and carboxylic functional groups. The transfer of the cation to the organic phase might occur through the formation of the Nd(HE)A2 complex (where A is either a nitrate or a chloride anion), allowing for the lowest associated standard Gibbs free energy of transfer (−28 < ΔG° < −24 kJ mol−1) regardless of the aqueous feed.

STUDIES THE CRUCIAL ROLE OF SELECTION OF EXTRACTANT TO EXTRACT NIOBIUM FROM SULFURYL FLUORIDE SOLUTION AND OPTIMIZATION OF EXTRACTION CONDITIONS

The increasing demand for rare refractory metals such as niobium in high-tech industries requires the development of efficient and sustainable methods to extract them from secondary sources, including industrial by-products. This study studied niobium extraction from a fluoride-sulfuric acid solution obtained by leaching a niobium-containing intermediate product. A comprehensive assessment of various organic extractants, including methyl isobutyl ketone, tributyl phosphate, trioctylamine, and Cyanex 923, was performed, focusing on the recoverability of niobium from this solution. Experimental results show that Cyanex 923 is significantly superior to other extractants in efficacy. The extraction of niobium at different concentrations of this extractant in toluene and the ratios of organic and aqueous phases were studied. It is established that an increase in the contact time of the phases does not contribute to additional niobium recovery. Studies show that applying concentrated Cyanex 923 in toluene ensures complete recovery of niobium into the organic phase. The three-stage counter-current extraction shows a slightly higher niobium recovery efficiency than the single-stage process.

EXTRACTION AND CONCENTRATION OF RHENIUM FROM NITRATE-CONTAINING RHENIUM DESORBATE

Extraction technology plays a key role in the industrial production of rhenium, accounting for more than 70% of the world's production of this element. In aqueous and alkaline solutions, rhenium is present in the form of the anion ReO4 - , which necessitates the use of anion exchange extractants based on tertiary amines. Despite the widespread application and many years of research on rhenium extraction with amines, the obtained data remain contradictory. The extraction of rhenium from aqueous solutions by an amine extractant occurs through an anion exchange mechanism with the formation of the complex TAAHReO4. To increase the solubility of amine salts in the organic phase, high-molecular-weight aliphatic alcohols, such as decyl alcohol, are added, which act as modifiers of the organic phase without extracting rhenium themselves. The aim of this work is to investigate the extraction of rhenium with trialkylamine from a model solution that simulates the composition of nitrate desorbate obtained from the processing of uranium ores. Specifically, various factors affecting the extraction and reextraction of rhenium are studied to determine the optimal parameters of these processes. The study uses trialkylamine as the extractant and decyl alcohol as the modifying additive. The results of the study show that the optimal parameters for rhenium extraction are: an extractant concentration of TAA:DA:kerosene=40:5:55 (% by volume), an organic to aqueous phase ratio of V_org/aq = 1:5, an extraction time of 5 minutes, and a rhenium extraction rate of up to 75%. Similar results were obtained with an extractant concentration of TAA:DA:kerosene = 30:10:60 and an extraction time of 5 minutes, where the rhenium extraction rate was about 74%. The re-extraction of rhenium is most efficiently carried out using an ammonia solution with a concentration of 114 g/L NH3⋅H2O and a phase contact time of 10 minutes, with a re-extraction rate of 85.5%. Similar results were obtained with the addition of 174 g/L (NH4)2SO4, where the rhenium re-extraction rate was 82%.

Alkaline Hydrolysis of Tri-iso-amyl Phosphate in n-dodecane Using Sodium Hydroxide: Part 1—Factors Affecting the Hydrolysis Process

Tri-iso-amyl phosphate (TiAP) is being proposed as a suitable alternate to tri-butyl phosphate mainly for the reprocessing of high-Pu-content spent fuel from fast reactors. After its use in a few cycles, the solvent has to be categorized as organic waste, which needs further treatment and disposal. Toward this, systematic studies have been carried out on the alkaline hydrolysis of TiAP in n-dodecane (n-DD) using sodium hydroxide (NaOH). The experiments were carried out in a stainless steel autoclave with a reactor vessel having a 1 L processing capacity. The parameters, such as mixing intensity, temperature, aqueous-to-organic phase volume ratio, and initial NaOH concentration, that can affect the kinetics of the hydrolysis reaction were studied. During each experiment, the TiAP concentration in the organic phase decreased steadily with time followed by a sudden decrease, which could be due to the autocatalytic hydrolysis of TiAP. After the completion of the hydrolysis reaction, the organic phase was mainly n-DD with iso-amyl alcohol, suggesting complete hydrolysis of TiAP to its aqueous-soluble hydrolysis products. Based on the studies, it was observed that temperature and initial NaOH concentration, among other parameters, highly influence the rate of hydrolysis of TiAP.

Binding mechanisms of trivalent chromium on colloidal phases from ultramafic systems: Insights from batch experiments and XAS analysis

Understanding the availability and mobility of chromium is a key factor in gaining insight into the fate of chromium and thus essential for assessing the risk of contamination and developing effective remediation strategies. In the natural environment, such as ultramafic systems, which are natural pools of chromium, chromium occurs mostly in the trivalent state (Cr(III)), which is known to have a high affinity for the solid phases such as particles and colloids. However, since Cr(VI) is more toxic, the vast majority of experimental studies focus on its reduction to Cr(III), which is often considered to form (hydr)oxide precipitates due to its poor solubility. Furthermore, while the oxidation state of Cr dictates its geochemical behavior, its interaction with particles and colloids is rarely controlled or monitored. Therefore, the interaction mechanisms between Cr(III) and particles or colloids require further attention. In this study, ten mineral phases (goethite, hematite, pyrolusite, kaolinite, montmorillonite, chlorite, serpentine, fuchsite, amphibole, and chromite) and one organic phase (humic acid), relevant to chromium bearing and carrier phases in ultramafic soils, were investigated to explore their interaction with Cr(III) species. These phases were first characterized by various techniques (including XRD, XRF, SEM, and BET). Adsorption and desorption experiments of Cr(III) on these phases were then carried out, and the distribution of Cr oxidation states in both the aqueous and solid phases was carefully monitored using UV–vis spectroscopy, geochemical speciation modeling, and Cr K-edge XAS spectroscopy. With the exception of pyrolusite, where partial oxidation of Cr(III) to Cr(VI) occurred, Cr(III) was shown to persist as a single oxidation state in all experiments. Desorption analyses showed significantly low desorbed rates, which further confirmed the prevalence of Cr(III). Experimental sorption isotherm data were interpreted using the Langmuir model and its linearized form, which provides important thermodynamic characteristics of adsorbents related to their structural and surface features. This study will provide better constraints for the understanding and prediction of Cr behavior and fate in the environment, especially in ultramafic systems.

Fatty Acids as Phase Change Materials for Building Applications: Drawbacks and Future Developments

The worldwide population growth and its increasing affluence have led to an increase in global building energy consumption. Therefore, developing sustainable energy storage materials to mitigate this problem has become a high priority for many researchers. Organic phase change materials (PCMs), such as fatty acids, have been extensively studied for thermal energy storage in building applications due to their excellent performance in absorbing and releasing energy within the environment temperature ranges. However, issues related to their thermal conductivity, stability, and flammability could limit the potential and require addressing. In this review, organic PCMs, with a special focus on fatty acids, are discussed. This review covers recent studies related to PCM synthesis from bio-sources, methods for PCM incorporation in building materials, methods for enhancing organic PCM thermal properties, flammability challenges, and life cycle assessment. Finally, future opportunities are summarized.

Liquid-liquid extraction of selenium (IV) ions from hydrochloric acid solution using Aliquat 336 dissolved in kerosene.

Solvent extraction of selenium(IV) ions from highly concentrated hydrochloric acid using 0.4mol/L Aliquat 336 dissolved in kerosene was investigated. As a modifying agent, 1-octanol (10% v/v) was added to the organic phase to avoid the third phase formation. The effect of different parameters affecting the liquid-liquid extraction of selenium(IV) such as the acid concentration, shaking time, metal ion concentration in the aqueous phase, loading capacity, diluents, and temperature, was studied. The results indicate that selenium(IV) is extracted efficiently by 0.4mol/L Aliquat 336 dissolved in kerosene. It was noticed that the extraction increased with the increase in the acid and Aliquat 336 concentrations, reaching an extraction percentage of about 92% at 8mol/L HCl and 97.1% at 1mol/L extractant. The extracted organic species is postulated to be [H2SeO2Cl2.2R4NCl]org by using the slope analysis method, and the value of Kex for selenium(IV) extraction was found to be 26.17 ± 2 M- 2. The structure of the extracted organic species was confirmed by FT-IR. The effect of diluents using various aliphatic and aromatic diluents indicated that kerosene is the most preferred diluent. This is owing to safety ground purpose, economic consideration, the lower cost, availability, and lower toxicity. Thermodynamic parameters indicate the endothermic nature for the solvent extraction of selenium(IV) for the investigated system according to the positive value obtained of the enthalpy change (ΔH). Depending on the obtained results, the method was used to recover selenium(IV) from a simulated solution synthesized in hydrochloric acid medium, which is expected in anode slime leach liquor solution.

Thin-film composite nanofiltration membrane based on polysulfonamide for extremely acidic conditions

Increasing the acid stability and selectivity of nanofiltration (NF) membranes, which are used to treat acidic industrial effluents, is highly beneficial. A series of acid-stable NF membranes featuring polysulfonamide (PSA) separation layers were prepared through interfacial polymerization of branched polyethyleneimine (PEI), polyethylenepolyamine (PPA), and 1,3-benzenedisulfonyl chloride (BDSC) on a porous polyethersulfone (PES) substrate. The optimization of the membrane filtration performance involved analyzing the monomer content in both the aqueous and organic phases and adjusting the PEI-to-PPA ratio, thereby preparing ultrathin PSA layers. The influence of the PSA morphology and structure on the membrane filtration performance was examined. The most effectively optimized sample demonstrated a MgSO4 rejection rate of 95.4 ± 0.4 % and a water flux of 55.4 ± 1 L m–2h−1 at a pressure of 2.0 MPa. The acid stability of the membrane was assessed by examining the permeation, separation, and physicochemical properties before and after undergoing static acid-soaking tests. Following a 5-month exposure to 20 % (w/v) HCl or 20 % (w/v) H2SO4 aqueous solution, the optimal membrane maintained a MgSO4 rejection of 92.6 % at neutral pH, with a permeation flux of 68.2 L m–2h−1 under 2.0 MPa. Owing to their excellent selectivity, enhanced acid stability, structural controllability, and ease of functionalization, these PSA-NF membranes are promising for use in industries such as mining, semiconductor, and electroplating.

Integral fractionation of Arundo donax using biphasic mixtures of solvents derived from biomass: An environmentally friendly approach

Arundo donax, one of the most invasive plants in the world, but also a promising source of lignocellulose materials was employed as a feedstock for a biorefinery process. Water-extracted Arundo donax samples were subjected to one-step biphasic fractionation in catalyzed media containing water and 1-butanol, an environmentally-friendly solvent. The effects of selected operational variables (catalyst concentration, temperature and reaction time) on the measured effects (solid recovery yield and compositions of the solid, aqueous and organic phases resulting from treatments) were assessed using statistical methods. The results allowed a quantitative discussion on aspects regarding the selectivity of component separation (lignin, glucan, and hemicelluloses), the overall recovery of valuable products, and the selection of operational conditions enabling extensive delignification (around to 90 %) and high recovery rates of glucan and hemicellulose-derived sugars (above 80 % and 75 %, respectively). This study provides new insights into biphasic fractionation, highlighting the selective separation of hemicellulose, cellulose and lignin into a single and sustainable process, thereby by enhancing biomass resource while reducing environmental impact.

Modulating interfacial polymerization by combination of organic phase additives and trimesoyl chloride for preparing high-performance thin-film nanocomposite reverse osmosis membranes

Incorporating hydrophilic nanoparticles into organic phase during interfacial polymerization (IP) to establish covalent bonds with organic phase monomers has proven to be a successful approach for fabricating high-performance thin-film nanocomposite (TFN) reverse osmosis (RO) membranes. However, the effect of covalent bonds number on the membrane structure and properties remains uncertain. Herein, hydrochloric acid doped polyaniline (PANI-HCl) with a small amount of amine groups and inherent polyaniline (PANI-base) nanomaterials with a larger amount of amine groups were prepared as organic phase additives for preparing high-performance TFN RO membranes. The amine groups on the nanoparticles can bond covalently with the acyl chloride groups of trimethyl chloride (TMC), leading to the accumulation of TMCs at organic/aqueous interface and accelerates IP reaction rate, resulting in a thinner, denser polyamide layer with more leaf-like structures and free volume. The water permeance of the PANI-base-RO membrane was improved by 62.5 % from 0.8 to 1.3 Lm−2h−1bar−1, and the NaCl rejection was improved from 97.6 % to 99.4 % compared with the pristine membrane. Overall, this work highlights the beneficial impact of organic phase additives with more amine groups on enhancing the desalination performance of RO membranes, providing valuable insights for the structural design of additives and dispersing medium selection.

Design of a hybrid nanoscaled skin photoprotector by boosting the antioxidant properties of food waste-derived lignin through molecular combination with TiO2 nanoparticles

TiO2 nanoparticles loaded with pistachio shell lignin (8 % and 29 % w/w) were prepared by a hydrothermal wet chemistry approach. The efficient interaction at the molecular level of the biomacromolecule and inorganic component was demonstrated by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV–Visible (UV–Vis), Fourier transform infrared (FT-IR), dynamic light scattering (DLS), and electron paramagnetic resonance (EPR) analysis. The synergistic combination of lignin and TiO2 nanoparticles played a key role in the functional properties of the hybrid material, which exhibited boosted features compared to the separate organic and inorganic phase. In particular, the hybrid TiO2-lignin nanoparticles showed a broader UV–Vis protection range and remarkable antioxidant performance in aqueous media. They could also better protect human skin explants from the DNA damaging effect of UV radiations compared to TiO2 as indicated by lower levels of p-H2A.X, a marker of DNA damage, at 6 h from exposure. In addition, the samples could protect the skin against the structural damage occurring 24 h post UV radiations by preventing the loss of keratin 10. These results open new perspectives in the exploitation of food-waste derived phenolic polymers for the design of efficient antioxidant materials for skin photoprotection in a circular economy perspective.