Solvent Mixtures Research Articles

Solvatochromic Analysis of Triton X-100 in Binary Mixtures

Binary solvent mixtures of the non-ionic surfactant Triton X-100 with water, methanol, ethanol, and 1-propanol, respectively, were investigated by solvatochromic studies. The absorption spectral bands of methyl red dye, used as a solvatochromic probe, were recorded in ternary solutions prepared with different mole ratios between Triton X-100 and water/alcohols. The Kamlet–Abboud–Taft model was applied to estimate the contribution of each type of intermolecular interaction to the total shift of the electronic absorption band of the solute. The composition of the solute molecule’s first solvation shell was comparatively estimated by using three models: the statistical cell model of ternary solutions, the Suppan model, and the Bosch–Rosés model. The statistical cell model allows the estimation of the difference between the interaction energies in the solute–solvent pairs of molecules. The Bosch–Rosés model provided important information on the 1:1 complex formed between Triton X-100 and water/alcohol molecules, as well as on the symmetry/asymmetry related to the binary mixtures in the cybotactic region of the solute’s molecule.

Method for extracting elemental sulfur in environmental water and its application to blue tide samples from Tokyo Bay, Japan.

A simple method for determining elemental sulfur in environmental water was developed and applied to seawater samples collected immediately after the occurrence of blue tides in Tokyo Bay. To investigate the concentration and extraction methods, artificial elemental sulfur was quantitatively produced by oxidizing a sulfide solution with an iodine solution, then used as a standard reagent in the experiments. To concentrate the elemental sulfur in the water sample, glass filter paper (GF/F) was used to filter and collect the elemental sulfur. The elemental sulfur was then extracted using n-hexane, the main component of petroleum ether; however, the recovery of elemental sulfur from the wet glass filter paper was low, and remained so even when the glass filter paper was dried. We, therefore, used a mixture of n-hexane and an acetone solvent, which is a hydrophilic organic solvent, for extraction and succeeded in recovering more than 90% of the elemental sulfur from the wet glass filter paper. Using this solvent mixture, we extracted and quantified elemental sulfur from seawater samples collected after the occurrence of blue tide, and detected 0.36-0.38 mgS L-1 of elemental sulfur in the near-surface layer. We also found that the elemental sulfur concentrations were higher in the surface layer than in the bottom layer. Therefore, we demonstrated that the quantification of elemental sulfur is important to better understand the blue tide phenomenon.

Preliminary Metabolomics and Determination of a Potent Anti-inflammatory Fraction of Freshwater Brown Algae

Objective: The study aims to perform preliminary metabolomics and identify the potent anti-inflammatory fractions from freshwater brown algae extract. Materials and Methods: The brown algae sample was harvested from the exposed rocks in Ebonyi River in Nigeria, and was subjected to cold maceration in a methanol-dichloromethane (2:1) solvent mixture for 72 hours, for extraction. The resulting extract was concentrated and subsequently fractionated via vacuum liquid chromatography (VLC) using solvent gradients of n-hexane and ethyl acetate. Acute toxicity was evaluated in Swiss albino mice according to Lorke’s method, with mortality rates employed to determine the LD50. The anti-inflammatory potential of the fractions was assessed using both in vitro (protein denaturation and heat-induced hemolysis assays) and in vivo (acetic acid-induced vascular permeability and xylene-induced edema) models. Doses of 50 and 100 mg/kg as well as 1 and 2 mg of the fractions (3:7, 5:5, 7:3) were administered orally and topical for the in vivo models respectively, while doses ranging from 62.5 to 1000 μg were used for the in vitro test. Dexamethasone was used as the positive control. High-performance liquid chromatography (HPLC) dereplication was employed to identify the phytoconstituents of the fractions. Results: Many anti-inflammatory compounds, including quercetin, ellagic acid and Kaempferol were identified in the fractions which would have accounted for the pronounced anti-inflammatory properties observed. Fraction 5:5 showed a superior anti-inflammation compared to dexamethasone in the xylene-induced edema model, although not statistically significantly different. Conclusion: These fractions, especially 5:5 can be further developed for the treatment of inflammation.

Polar Pore Surface of Polyamide Membranes Enabling Efficient Solvent Mixture Separation

AbstractSeparating solvent mixtures without phase change using polyamide membranes reduces energy consumption and enhances environmental sustainability. However, overemphasizing precise pore control while neglecting membrane–solvent interactions hinder membrane development and reduces separation efficiency. Here, it is demonstrated that rapid separation of solvents of differing polarity can be achieved using a polyamide membrane featuring relatively large pores with a polar surface formed via interfacial polymerization between polyethyleneimine (PEI) and trimesoyl chloride (TMC). The abundant amine groups and flexible chains of PEI facilitate the formation of a polyamide network that enables fast and selective transport of mixed solvents with varying polarity. The membrane can exhibit several‐fold‐higher permeance while maintaining comparable permselectivity compared to conventional polyamide membranes fabricated from the reaction of m‐phenylenediamine with TMC. This work leverages membrane–solvent interactions to achieve solvent mixture differentiation and may guide the development of high‐performance polymer membranes for efficient solvent mixture separation.

Aqueous Mixtures of Deep Eutectic Solvents: Tuning the Reaction Medium and Photocatalyst for Highly Selective Amine Oxidation

AbstractHarvesting light as a source of energy for driving chemical processes is an important aspect of tacking the looming energy crisis. The challenge lies in making the process sustainable while retaining the efficiency and selectivity. In this work, deep eutectic solvents and their aqueous mixtures are used to replace acetonitrile as the reaction medium for the photocatalyzed amine oxidation. It is observed that the use of deep eutectic solvents as reaction media leads to >90% conversion but presents issues with efficient workup due to high viscosity. The use of water a cosolvent mitigates the issue. Further modification of the catalyst surface with alizarin enables the use of higher water content (in a 1:1 ratio) and leads to high conversion (>90%) at one-tenth of irradiation intensity. The high yield and selectivity eliminate the need for tedious purification steps to isolate the product. Control experiments indicate cooperative contributions by TiO2, 2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO), and alizarin as mechanistic factors responsible for the enhanced reactivity.

Rapid and Simple Dispersive Liquid-Liquid Microextraction (DLLME) Sample Preparation for Propofol Analysis in Hair, Blood, and Urine by Gas Chromatography-Mass Spectrometry.

Propofol is a widely used anesthetic. Although considered safe, propofol-related deaths occur, as it is sometimes abused recreationally or used to commit suicide. A simple, rapid, and reliable method for its analysis in various biological samples is needed. Sample clean-up is a critical step in the analysis, both in terms of time and cost, indeed. Dispersive liquid-liquid microextraction (DLLME) is a simple and fast extraction based on ternary solvent mixtures that uses small volumes of solvent and sample. A DLLME extraction followed by gas chromatography-mass spectrometry (GC-MS) analysis was developed and validated for the analysis of propofol in blood, urine, and hair. The same extraction mixture of 2.5:1 methanol/chloroform was used for the different biological samples. Validation for linearity, LOD, LOQ, precision, accuracy, and recovery gave satisfactory results for the three types of biological samples included in the study, with limits of quantification of 1 μg/mL for urine, 0.2 μg/mL for blood, and 0.1 ng/mg for hair. The DLLME procedure for purification involves a small amount of solvent, thus reducing the cost and the environmental impact. In addition, a high enrichment factor is obtained, and the time for analysis is short. The method was applied to authentic post-mortem samples for the determination of propofol in blood, urine, and hair. Also, segmental hair analysis was performed to assess chronic propofol abuse. The developed method proved to be rapid, simple, and cost-effective for blood, urine, and hair extract clean-up for the determination of propofol by GC/MS.

Green Recovery of Toxic Prussian White Cathode From Spent All‐Climate Sodium‐Ion Batteries Using Low‐Melting Mixture Solvents (LoMMSs)

ABSTRACTA large number of spent sodium‐ion batteries (SIBs) will be produced as SIBs become more widely used. However, components of spent SIBs, such as the cathode Prussian white Na2Mn[Fe(CN)6], are toxic and hazardous, leading to water and soil pollution and posing a threat to human health. Therefore, recycling spent SIBs cathode is important and meaningful. Here, we use phytic acid‐based low‐melting mixture solvents (LoMMSs) for the efficient recovery of toxic and hazardous SIBs cathode Prussian white at mild temperatures. Results show that the highest Na leaching efficiency from Prussian white could reach 94.7% by polyethylene glycol 200:phytic acid (14:1) at 80°C for 24 h with a liquid/solid ratio of 50:1. Furthermore, the metal extracted from the leachate is found to precipitate when water is used as the anti‐solvent, with ammonium hydroxide achieving the highest precipitation efficiency of 89.3% at room temperature.

Carbazole-Based Eu3+ Complexes for Two-Photon Microscopy Imaging of Live Cells.

Lanthanide(III) complexes with two-photon absorbing antennas are attractive for microscopy imaging of live cells because they can be excited in the NIR. We describe the synthesis and luminescence and imaging properties of two Eu3+ complexes, mTAT[Eu·L-CC-Ar-Cz] and mTAT[Eu·L-Ar-Cz], with (N-carbazolyl)-aryl-alkynyl-picolinamide and (N-carbazolyl)-aryl-picolinamide antennas, respectively, conjugated to the TAT cell-penetrating peptides. Contrary to what was previously observed with related Eu3+ complexes with carbazole-based antennas in a mixture of water and organic solvents, these two complexes show very low emission quantum yield (ΦEu < 0.002) in purely aqueous buffers. A detailed spectroscopic study on mTAT[Eu·L-Ar-Cz] reveals that the quantum yield of emission is strongly polarity dependent─the less polar the medium, the higher the quantum yield─and that the emission quenching in water is likely due to a photoinduced electron transfer between the excited carbazole-based antenna and Eu3+ that efficiently competes with the energy transfer process. Nevertheless, mTAT[Eu·L-Ar-Cz] shows a significant two-photon cross-section of 100 GM at 750 nm, which is interesting for two-photon microscopy. The live cell imaging properties of mTAT[Eu·L-Ar-Cz] and the two other conjugates were investigated. Cytosolic delivery was clearly evidenced in the case of mTAT[Eu·L-Ar-Cz] when cells are coincubated with this compound and a nonluminescent dimeric TAT derivative, dFFLIPTAT.

Effect of Thermal Treatment on the Extraction and Antioxidant and Antiglycation Activities of (Poly)phenols from Ribes magellanicum.

Phenolic compounds have antiglycation activity, but the changes occurring during thermal treatment (TT) in these activities are not completely understood. The effects of the extraction conditions of (poly)phenols from Ribes magellanicum fruits, before and after TT, on their antioxidant and antiglycation effects were assessed. (Poly)phenol-enriched extracts (PEEs) from raw and TT (90 °C, 1 h) Ribes magellanicum were extracted using three solvent mixtures (ethanol/water/acetic acid) with increasing water content (0, 24, and 49%) and three solvent-to-solid ratios (5, 10, and 20 mL/g). PEEs of raw samples showed increased values of total (poly)phenols (TPC), TEAC, and FRAP and decreased IC50 values of fluorescent advanced glycation end products (AGEs) with increasing water content. An increase in TPC and FRAP values was observed for TT samples, but an increase in the IC50 values of fluorescent AGEs for PEEs with increasing water content was observed. Antiglycation activity (IC50 raw/IC50 TT) depended on the solvent-to-solid ratio and the extracting solvent. HPLC-DAD-MS analysis of raw and TT samples showed degradation of anthocyanins, flavonoid fragmentation, and oxidation as the main changes in the phenolic composition of TT samples. We show that TT affects the (poly)phenolic composition of R. magellanicum, producing a decrease in the antiglycation activity when extractions are performed with increasing water content, despite increasing TPC and FRAP activity.

2-Amidophenolate and 2-Iminosemiquinone Radical-Coordinated Vanadyl Complex as Catholyte for Non-Aqueous Redox-Flow Batteries.

Fulfilment of energy demand by utilizing renewable energy sources that do not contribute to the production of greenhouse gases is a step forward in mitigating global warming. However, with the energy sources being intermittent in nature, renewable energy needs to be stored effectively on a grid scale. In this context, the development of redox-flow batteries has emerged as a promising technology where charging and discharging processes are accomplished by the redox shuttling of the electrolytes, namely anolytes and catholytes. This report describes the synthesis and characterization of a six-coordinate vanadyl complex (complex 1) with H4LSCH2(AP/AP) ligand comprising two redox-active (non-innocent) 2-aminophenol moieties. The metal ion-coordinated deprotonated ligand, which was in {[LSCH2(AP/ISQ)]3-} form, encountered one-electron reversible oxidation at 0.46 V vs Ag/AgCl where the 2-amidophenolate ([AP]2-) unit was being oxidized to [ISQ]•- radical. Using this redox phenomenon, a static H-cell was constructed in a 1:1 CH3CN:CH2Cl2 solvent mixture where galvanostatic charge/discharge cycles, in the potential range 0 to +0.8 V vs Ag/AgCl, were performed for 54 hours without noticeable degradation of the complex. GCD experiment provided a columbic efficiency (CE) of 97% and energy efficiency (EE) of 71%.

Synergistic Chloroform-Methanol Binary Solvent Mixture Is Inherently Spatially and Dynamically Heterogeneous.

Nonideality in a binary solvent mixture is manifested through anomalies in various physical properties like viscosity, dielectric constant, polarity, freezing point, boiling point, and so forth. Sometimes, such anomalies become much more prominent, leading to a synergistic behavior, where the physical property of the mixture is way different from its bulk counterparts. Various alcohols/chlorinated methane binary solvent mixtures show such a synergistic behavior. The reason is attributed to the unique but diverse interactions present in the system. We speculated that these diverse interactions must manifest heterogeneity in such a binary solvent mixture. Using the improved methodology developed by our group, we investigate the presence of dynamic and spatial heterogeneity in the chloroform/methanol synergistic binary solvent mixture. To our delight, we found that our projection is accurate, and indeed, the chloroform/methanol binary solvent mixtures are heterogeneous. Two maxima for the synergistic behavior have been observed for the chloroform/methanol binary solvent mixture (at ∼0.45 and 0.75 mole fractions of methanol in chloroform) in the literature, where the extent of heterogeneity was also found to be the highest. The present study portrays the intriguing complexity of simple binary solvent mixtures, and the findings may provide valuable insights into solvent engineering for diverse applications like extraction/purification media, reaction media, polymer processing, nanomaterial synthesis, pollutant extraction, active ingredient delivery, biofuel production, and battery technology.

Enthalpy-Driven Interaction between Bovine Serum Albumin and Biomass-Derived Low-Melting Mixture Solvents (LoMMSs) for Efficient and Green Purification of Protein.

Green separation of protein (e.g., bovine serum albumin (BSA)) by low-melting mixture solvents (LoMMSs) depends on the underlying mechanism between BSA and LoMMSs. Here, we for the first time find that eco-friendly biomass-derived LoMMSs could be potentially used for the efficient and green purification of BSA protein by enthalpy-driven interactions. Biomass-derived LoMMSs possess the merits of high biocompatibility, high degradability, high abundance, and low cost. A single high-affinity binding site via hydrogen bonding and van der Waals forces is observed between BSA and LoMMSs by fluorescence and thermodynamic analysis. Experimental results from circular dichroism and infrared spectra demonstrate that the addition of LoMMSs stabilizes the secondary structure of the BSA protein. This work provides a valuable indication for the design of eco-friendly and cost-effective LoMMSs for the purification of protein.

Lipidomic Signature of Pregnant and Postpartum Females by Longitudinal and Transversal Evaluation: Putative Biomarkers Determined by UHPLC-QTOF-ESI+-MS.

Pregnancy induces significant physiological and metabolic changes in the mother to support fetal growth and prepare for childbirth. These adaptations impact various systems, including immune tolerance, metabolism, and endocrine function. While metabolomics has been utilized to study pregnancy-related metabolic changes, comprehensive comparisons between pregnant and non-pregnant states, particularly using ultra-high-performance liquid chromatography coupled with mass spectrometry (UHPLC-MS), remain limited. This study aimed to explore the dynamic, longitudinal metabolic shifts during pregnancy by profiling plasma samples from 65 pregnant women across three time points (6-14 weeks, 14-22 weeks, and >24 weeks) and 42 postpartum women. Lipidomics was prioritized, and a solvent mixture was employed to enhance lipid extraction, using UHPLC-QTOF-ESI+-MS. A total of 290 metabolites were identified and analyzed. Our results revealed significant metabolic differences between pregnant and postpartum women, with lipid molecules such as estrogen derivatives, fatty acids, and ceramides showing strong potential as biomarkers. Further biomarker analysis highlighted distinct metabolic signatures between early and late pregnancy stages, particularly in lipid metabolism (with AUC values > 0.8). These findings contribute to a deeper understanding of pregnancy-related metabolic changes and may offer insights into maternal and neonatal health outcomes.

Enhanced Ion Solvation and Conductivity in Lithium-Ion Electrolytes via Tailored EMC-TMS Solvent Mixtures: A Molecular Dynamics Study.

The development of stable, high-performance electrolytes is essential to addressing the safety concerns and limited lifespan caused by the thermal and chemical instability of traditional organic carbonate-based electrolytes in lithium-ion batteries (LIBs). This study examined the potential of mixed solvent systems, specifically ethyl methyl carbonate (EMC) and tetramethylene sulfone (TMS), to modify ion solvation and improve ionic conductivity in LIB electrolytes. Through molecular dynamics simulations, we investigated the solvation structure and transport properties of lithium ions (Li+) in these solvent environments. The inclusion of TMS altered the solvation structure, with TMS molecules preferentially coordinating with Li+ ions, displacing PF6 - anions and reducing their electrostatic interference. Our results demonstrated a synergistic interaction between EMC and TMS, where an EMC/TMS ratio of 1:2 led to a significant improvement in ionic conductivity, reaching 0.91 mS/cm, with a corresponding Li+ transference number of 0.40. These findings provide key insights into the molecular-level interaction governing electrolyte behavior, offering guidance for the design of future solvent mixtures to improve the safety and efficiency of LIBs.

Identification of ketamine and norketamine in dried bloodstains on crime-scene surfaces

BackgroundToxicological analysis of dried bloodstains (DBS) provides critical information for reconstructing the sequence of events at a crime scene. Drugs have higher stability in DBS relative to liquid blood owing to the arrest of enzymatic reactions in dehydrated samples. However, literature on the identification of ketamine and its metabolites in DBS is limited and is mostly focussed on the analysis of bloodstains collected on paper cards. The present study has analysed the stability of ketamine and norketamine in DBS aged on common crime scene surfaces under various storage temperatures. Coloured linen fabric and glass slide, representing porous and non-porous surfaces, respectively, were stained with a defined volume of drug-fortified whole blood and stored at room temperature (20 °C), in the refrigerator (4 °C), and freezer (− 20 °C) for 1, 7, and 14 days. Analytes were solvent-extracted using a dichloromethane: hexane (1:3 v/v) mixture, followed by gas chromatography-mass spectrometry (GC–MS) analysis with ketamine-d4 as the internal standard.ResultsAt least 4.3 ng/mL and 8.7 ng/mL ketamine and norketamine, respectively, were detected in dried stains prepared from 5 to 50 µL whole blood corresponding to a concentration range of 10–100 ng/mL. The GC–MS method was linear in this range with a coefficient of determination, R2 > 0.99. Recovery of the analytes was comparable (~ 100–120%) between DBS porous and whole blood, whereas it was considerably lower (~ 50%) in DBS non-porous samples due to the incomplete transfer of the stains from the glass into the extraction solvent mixture. Analyte response in DBS showed a strong correlation with that in whole blood at four concentration levels (0.1–5 µg/mL). Mean precision values (% CV) for biological and technical replicates (n = 5) were 15.0 and 6.5, respectively, and within an acceptable range.ConclusionsThe developed method for the analysis of ketamine and norketamine in DBS is comparable to that in other biological matrices such as whole blood under short-term storage conditions. Lower temperatures are favourable for maintaining the integrity of the samples; however, the bloodstains must be completely dried before storing them in the refrigerator or freezer for short-term (1–7 days) to prevent hydrolytic degradation of drugs.Graphical

Orderly Arranged Cubic Quantum Dots along Supramolecular Templates of Naphthalenediimide Aggregates.

Precise control of assembled structures of quantum dots (QDs) is crucial for realizing the desired photophysical properties, but this remains challenging. Especially, the one-dimensional (1D) control is rare due to the nearly isotropic nature of QDs. Herein, we propose a novel strategy for controlling the 1D-arrangement range of cubic perovskite QDs in solution based on the morphological modification of a supramolecular polymer (SP) template. The original template with a short and tangled fibrous structure is prepared in a low-polarity solvent mixture via self-assembly of a naphthalenediimide-functionalized cholesterol derivative with an adhesion group for QDs. Mixing this template with QDs leads to the co-aggregation into short-range 1D-arrays of QDs on the templates. Notably, subsequent heating and cooling of the co-aggregate solution forms longer-range 1D-arrays of QDs with lateral growth, where arranged QDs are sandwiched between reconstructed SP templates. Furthermore, the longer-range 1D-array of QDs is achieved via an alternative route involving the pre-organization of templates into longer and dispersed fibers by heating and cooling of the original template, succeeded by co-assembly with QDs. Finally, we reveal continuous fluorescence resonance energy transfer between 1D-arranged QDs by an in-depth analysis of the photoluminescence decay curves.

Water-soluble platinum and palladium porphyrins with peripheral ethyl phosphonic acid substituents: synthesis, aggregation in solution, and photocatalytic properties.

Water-soluble porphyrins have garnered significant attention due to their broad range of applications in biomedicine, catalysis, and material chemistry. In this work, water-soluble platinum(II) and palladium(II) complexes with porphyrins bearing ethyl phosphonate substituents, namely, Pt/Pd 10-(ethoxyhydroxyphosphoryl)-5,15-di(p-carboxyphenyl)porphyrins (M3m, M = Pt(II), Pd(II)) and Pt/Pd 5,10-bis(ethoxyhydroxyphosphoryl)-10,20-diarylporphyrins (M1d-M3d; aryl = p-tolyl (1), mesityl (2), p-carboxyphenyl (3)), were synthesized by alkaline hydrolysis of the corresponding diethyl phosphonates M6m and M4d-M6d. NMR, UV-vis, and fluorescence spectroscopy revealed that the mono-phosphonates M3m tend to form aggregates in aqueous media, while the bis-phosphonates M3d exist predominantly as monomeric species across a wide range of concentrations (10-6-10-3 M), ionic strengths (0-0.81 M), and pH values (4-12). Single-crystal X-ray diffraction studies of the diethyl phosphonates Pt6d and Pd6d revealed that π-π stacking of the aromatic macrocycles is sterically hindered in the crystals, providing a rationale for the low degree of solution aggregation observed for ethyl phosphonate M3d. Photophysical studies of M3m and M1d-M3d demonstrated that these compounds are phosphorescent and generate singlet oxygen in aqueous solutions. Pd(II) complex Pd3d is an excellent photocatalyst for the oxidation of sulfides using di-oxygen in a solvent mixture (MeCN/H2O, 4 : 1 v/v). Under these conditions, various alkyl and aryl sulfides were quantitatively converted into the desired sulfoxides. For the oxygenation of mixed alkyl-aryl sulfides, Pd3d outperforms Pd(II) meso-tetrakis(p-carboxyphenyl)porphyrin (PdTCPP). This photocatalyst can be recycled and reused to afford sulfoxides with no loss of product yield.

Effect of solvent on the development of Poly(2-ethyl-2-oxazoline) nanofibrous scaffolds using electrospinning technique for biomedical applications.

The selection of a biomaterial plays a very important role for the development of scaffolds for biomedical applications. Amidst, the development of nanofibrous scaffolds through electrospinning technique by selecting a suitable polymer is of more importance. Poly (2-ethyl-2-oxazoline) (PEOX) is one among the selected polymers that can be employed for electrospinning for the development of scaffolds for biomedical applications. PEOX is a water-soluble polymer which is highly desirable for biomedical applications. At the same time, PEOX is soluble in the mixture of organic solvents as well. In view of this, the present study is the preliminary study of using PEOX for the development of scaffolds by using electrospinning technique and to check its potentiality for biomedical application like tissue engineering for the future research. The PEOX scaffolds were fabricated using electrospinning process using water and organic solvents, and the effect of solvent was studied on the morphology and physical properties of the developed scaffolds. The Scanning Electron Microscopic results of the scaffolds showed a uniform nanofibrous structure in case of aqueous PEOX solution, whereas microfibrous structure was obtained for organic solvent. Wettability of the scaffolds was observed by contact angle measurement, which revealed that the hydrophilicity of the PEOX (aq.) scaffold was higher with the contact angle of 55.2° as compared to PEOX (org.) scaffold with the contact angle of 70.38°. Further, the mechanical strength of the scaffolds was calculated in terms of Young's modulus values and it was observed that the PEOX (org.) demonstrated a higher tensile strength of 1.9MPa compared to PEOX (aq.) scaffold with 1.02MPa respectively. The results thus clearly conclude that the nature of solvents greatly affect the electrospinning process of PEOX and thereby the properties of the developed PEOX scaffolds based on the solvent. Further, we can say that the developed PEOX scaffolds possess suitable properties to be employed for biomedical applications like tissue engineering.

Passivation, phase, and morphology control of CdS nanocrystals probed using fluorinated aromatic amines and solid-state NMR spectroscopy.

Nanocrystals are widely explored for a range of medical, imaging, sensing, and energy conversion applications. CdS nanocrystals have been reported as excellent photocatalysts, with thin film CdS also highly important in photovoltaic devices. To optimise properties of nanocrystals, control over phase, facet, and morphology are vital. Here, CdS nanocrystals were synthesised by the solvothermal decomposition of a Cd xanthate single source precursor. To attempt to control CdS nanocrystal surfaces and morphology, the solvent used in the nanocrystal synthesis was altered from pure trioctylphosphine oxide (TOPO) to a mixed TOPO : fluorinated aromatic amine (3-fluorobenzyl amine (3-FlBzAm) or 3-fluoroaniline (3-FlAn)), where 19F provides a sensitive NMR-active surface probe. Powder X-ray diffraction found that the CdS nanocrystals synthesised from TOPO : 3-FlAn solvent mixtures were predominantly cubic whilst the TOPO : 3-FlBzAm synthesised nanocrystals were predominantly hexagonal. Raman spectroscopy identified hexagonal CdS in all samples. Solid-state NMR of 113Cd, 19F, 13C, and 1H was employed to investigate the local Cd environments, surface ligands, and ligand interactions. This showed there was a mixture of CdS phases present in all samples and that surfaces were capped with TOPO : fluorinated aromatic amine mixtures, but also that there was a stronger binding affinity of 3-FlBzAm compared with 3-FlAn on the CdS surface, which likely impacts growth mechanisms. This work highlights that fluorinated aromatic amines can be used to probe NC surfaces and also control NC properties through their influence during NC growth.

Comparative Analysis of Needleless and Needle-Based Electrospinning Methods for Polyamide 6: A Technical Note.

This study investigates the influence of needleless versus needle-based electrospinning methods on the fiber diameter of polyamide 6 (PA6) nanofibers under comparable conditions, with an emphasis on potential pharmaceutical applications. Additionally, it examines how varying solvent systems impact fiber diameter specifically in needleless electrospinning. In this study, it was found that fibers produced by the needleless method were thicker compared to those produced by the needle-based method, a trend attributable to the specific solution characteristics and parameter settings unique to this study. Notably, a 2 : 1 acetic acid : formic acid solvent mixture yielded the largest fiber diameters among the solvent systems assessed for needleless electrospinning. These results underscore the potential of PA6 nanofibers in pharmaceutical applications, suggesting that further optimization of electrospinning conditions could enhance their suitability. The study also discusses the implications of scale-up production using needleless technology, highlighting its viability for industrial applications over single-needle electrospinning.