Common Solvents Research Articles

Alveolar and gingival necrosis resulting from chloroform overextrusion beyond the root canal: A case report.

Chloroform is among the most common solvents for root canal treatment. Despite its classification as a potential carcinogen, it is effective if used correctly. Inappropriate use can lead to severe complications, including persistent pain, gingival recession, and necessitating surgical intervention to resect necrotizing bone.

Extraction solvents effect on asphalt binder properties

Asphalt industries are actively pursuing the integration of recycled asphalt pavement (RAP) into their constructions to promote sustainable pavement solutions amidst resource scarcity. However, challenges persist in the extraction and recovery processes, potentially affecting asphalt pavement performance assessments. This study investigates the impact of three common solvents—n-propyl bromide (nPB), trichloroethylene (TCE), and a toluene-ethanol blend (85 %/15 %)—on the rheological properties of recovered binders, particularly aiming to identify a substitute for TCE in light of its proposed ban by the Environmental Protection Agency (EPA) in the USA. Tests were conducted on six different performance-graded (PG) binders from diverse sources, assessing high-temperature properties using Dynamic Shear Rheometer (DSR) and Multiple Stress Creep Recovery (MSCR) tests, as well as low-temperature properties via Bending Beam Rheometer (BBR). Fourier Transform Infrared (FTIR) spectroscopy confirmed the absence of solvents in the recovered binders. Although minor variations were observed in measured properties between original and recovered binders due to solvent use, these differences did not affect the resulting performance grades. Thus, the toluene-ethanol blend can potentially substitute for TCE. However, it is noteworthy that the toluene-ethanol blend (85 %/15 %) displayed a slower solubility rate compared to nPB and TCE, underscoring the need for caution in its usage.

Synergistic Effects of Unconventional Hydrogen Bonds and π-Stacking Interaction and Their Excited-State Dependence: The Origin of Unusual Photophysical Properties of Aromatic Thioketones in Acetonitrile and Hydrocarbons.

It has been established experimentally that aromatic thioketones possess several inherently unique photophysical properties, some of which are highly sensitive even to common hydrocarbon solvents. However, the deeper reasons and the underlying mechanisms remain unclear up to date. In this study, the multistate complete active space second-order perturbation theory (MS-CASPT2) has been utilized to investigate the five lowest-lying electronic states (S0, T1, S1, T2, and S2) of 4H-1-benzopyran-4-thione (BPT) in acetonitrile and hydrocarbons. The results show that the S1, T1, and T2 states of BPT are close in energy so that the T2-state-mediated S1 → T2 → T1 and T1 → T2 → S1 transitions could occur in tens of picoseconds, which exhibits little dependence on the formation of the BPT-solvent complexes and on the bulk-solvent effect. This explains why thermally activated delayed fluorescence from the S1 state has been observed for many aromatic thioketones in both inert media and hydrocarbons. Meanwhile, our calculations show that the intracomplex noncovalent interactions could be automatically adjusted by the redistribution of π-electrons in the flexible aromatic rings. This allows the S2 → S1 internal conversion to occur efficiently in the vicinity of the two-state conical intersection, which results in the remarkable changes in the S2-state lifetimes and fluorescence quantum yields of many aromatic thioketones from inert media to hydrocarbon solvents. The aforementioned inherent photophysical properties could be qualitatively understood by a simple model of frontier molecular orbitals. This model could be used to understand photophysical properties of other aromatic compounds (such as aldehydes, ketones, amines, and carboxylic acids) in different solvents.

CONSIDERING DIMETHYL SULFOXIDE SOLVENT TOXICITY TO MAMMALIAN CELLS AND ITS BIOLOGICAL EFFECTS.

Dimethyl sulfoxide (DMSO) is a common solvent in biological and medical research for dissolving water-insoluble compounds and drugs. However, the impact of DMSO goes beyond its primary function. High-throughput and in vitro assays have uncovered various effects of DMSO in mammalian cells. The present article highlights the biological effects of DMSO on normal and cancerous mammalian cells.

Xanthenes: Novelty and Green Photocatalysis for the Formation of Carbon-carbon or Carbon-heteroatom Bond

: This review covers photoreduction reactions using xanthenes reported from 2011 to date and compares them with the conventional photocatalytic method. Xanthenes have strong absorption in the visible light spectrum (520-550 nm), and their redox potential resembles organometallic complexes, such as those containing Ir or Ru, and they are also easy to handle and accessible. In addition to being metal-free, photocatalysis with xanthenes is performed under mild reaction conditions. For instance, no radical initiators are needed because the energy sources are led devices or household lamps, most reactions are performed at room temperature in common solvents (MeOH, MeCN, acetone, DMSO), and an anhydrous or inert atmosphere is usually not required. As a result, xanthene dyes hold the promise of a more environmentally friendly synthesis of organic compounds.

Theoretical study of the efficiencies of graphyne supported Mo single-atom catalyst (SAC) and Mo-Ni dual-atom catalyst (DAC) on hydrogen evolution reaction

In this work, by adding one molybdenum atom or two molybdenum and nickel atoms on the surface graphyne support, single atom catalyst (SAC) and dual atoms catalyst (DAC) were designed. The different spin multiplicities for both catalysts were analyzed by the relative energies, adsorption energies and frontier orbitals. The results showed in both case of SACs and DACs, the catalyst with spin multiplicity = 3 is desired. Then, the efficiency of these two catalysts as high-performance and cost-effective catalysts in the HER process was investigated theoretically. All calculations were performed using M06-2X/def2SV level of theory. In the HER mechanism, it has been found that the DAC has higher favorability than the SAC. Both steps (Volmer reaction and Tafel or Heyrovsky reaction) are more exothermic using DAC, and the difference between SAC and DAC is higher in the second step. The effect of solvent on these steps has been studied using water and methanol as two common solvents. The reactions are less exothermic in the solvent; but they are still highly exothermic and thermodynamically favorable. Moreover, despite the gas phase data, in both solvents, the use of DAC gives less favorable data versus the SAC. The data also showed the little preference of water versus the methanol as solvent.

Prediction of Solvent Composition for Absorption-Based Acid Gas Removal Unit on Gas Sweetening Process.

The gas sweetening process is essential for removing harmful acid gases, such as hydrogen sulfide (H2S) and carbon dioxide (CO2), from natural gas before delivery to end-users. Consequently, chemical absorption-based acid gas removal units (AGRUs) are widely implemented due to their high efficiency and reliability. The most common solvent used in AGRU is monodiethanolamine (MDEA), often mixed with piperazine (PZ) as an additive to accelerate acid gas capture. The absorption performance, however, is significantly influenced by the solvent mixture composition. Despite this, solvent composition is often determined through trial and error in experiments or simulations, with limited studies focusing on predictive methods for optimizing solvent mixtures. Therefore, this paper aims to develop a predictive technique for determining optimal solvent compositions under varying sour gas conditions. An ensemble algorithm, Extreme Gradient Boosting (XGBoost), is selected to develop two predictive models. The first model predicts H2S and CO2 concentrations, while the second model predicts the MDEA and PZ compositions. The results demonstrate that XGBoost outperforms other algorithms in both models. It achieves R2 values above 0.99 in most scenarios, and the lowest RMSE and MAE values of less than 1, indicating robust and consistent predictions. The predicted acid gas concentrations and solvent compositions were further analyzed to study the effects of solvent composition on acid gas absorption across different scenarios. The proposed models offer valuable insights for optimizing solvent compositions to enhance AGRU performance in industrial applications.

Validation of An HPLC Method for the Determination of Some Β-Lactams Antibiotics Using A Green Analytical Technique

Green analytical chemistry (GAC) primary goal is to develop environmental and health-friendly analytical methods by reduction or replacement of hazardous substances from analytical procedures. In this research, the application of GAC to quantify five β-lactams antibiotics (cefuroxime sodium, cefaclor, ertapenem sodium, ampicillin sodium and sulbactam sodium) by high-performance liquid chromatography (HPLC) using photodiode arrays (PDA) detector was developed. To achieve this, ethanol was used as a green replacement for methanol and acetonitrile, common solvents in chromatographic procedures. Several chromatographic conditions were investigated to accomplish the optimal conditions. The method validation followed the ICH Q2 (R1) guideline, and the developed method was successfully applied for quantifying some pharmaceutical products.

Amino acid sensitive latent fingermark detection formulations based upon improvised carrier solvents for resource-limited environments: A proof-of-concept study

HFE-7100 and petroleum ether (bp 40–60 °C) are routine carrier solvents used in amino acid sensitive fingermark reagents such as 1,2-indanedione/zinc chloride (IND-Zn) and ninhydrin. However, limited resource jurisdictions face major challenges in sourcing laboratory-grade reagents due to budgetary and geographical restrictions. Common hydrocarbon solvents, available from hardware stores and similar outlets, may offer a more readily available and inexpensive alternative for such jurisdictions. This study assessed the range of improvised carrier solvents for their suitability in the IND-Zn formulation and found that eight different hydrocarbon solvents were able to develop fingermarks when substituted into the formulation. The formulation based on shellite solvent outperformed all other improvised formulations tested, providing high-quality fingermarks and similar sensitivity to a petroleum ether (bp 40–60 °C) based formulation across six porous substrates using six donors. A similar approach was applied to ninhydrin, where it was discovered that formulations using kerosene, white spirits and shellite as carrier solvents performed comparably to a formulation based on petroleum ether (bp 40–60 °C). By chemically characterising each solvent using gas chromatography-mass spectrometry, this study also provided a greater understanding of how the chemical composition of a carrier solvent impacts the efficacy of the resulting IND-Zn formulation, emphasising that hydrocarbon solvents should contain short-chain alkanes and minimal aromatic content to give a more volatile formulation. Additionally, the identity of the solvent was found to cause slight differences in the colour and luminescence intensity of ink diffusion on porous substrates. These results indicate that improvised hydrocarbon solvents are suitable alternatives to common carrier solvents with their operational use offering major benefits for limited resource jurisdictions by reducing costs and supply chain risks. A thorough risk assessment must be conducted by each jurisdiction that intends to use this method as health and safety considerations are concerns with these improvised solvents.

Accurately Predicting Barrier Heights for Radical Reactions in Solution Using Deep Graph Networks.

Quantitative estimates of reaction barriers and solvent effects are essential for developing kinetic mechanisms and predicting reaction outcomes. Here, we create a new data set of 5,600 unique elementary radical reactions calculated using the M06-2X/def2-QZVP//B3LYP-D3(BJ)/def2-TZVP level of theory. A conformer search is done for each species using TPSS/def2-TZVP. Gibbs free energies of activation and of reaction for these radical reactions in 40 common solvents are obtained using COSMO-RS for solvation effects. These balanced reactions involve the elements H, C, N, O, and S, contain up to 19 heavy atoms, and have atom-mapped SMILES. All transition states are verified by an intrinsic reaction coordinate calculation. We next train a deep graph network to directly estimate the Gibbs free energy of activation and of reaction in both gas and solution phases using only the atom-mapped SMILES of the reactant and product and the SMILES of the solvent. This simple input representation avoids computationally expensive optimizations for the reactant, transition state, and product structures during inference, making our model well-suited for high-throughput predictive chemistry and quickly providing information for (retro-)synthesis planning tools. To properly measure model performance, we report results on both interpolative and extrapolative data splits and also compare to several baseline models. During training and testing, the data set is augmented by including the reverse direction of each reaction and variants with different resonance structures. After data augmentation, we have around 2 million entries to train the model, which achieves a testing set mean absolute error of 1.16 kcal mol-1 for the Gibbs free energy of activation in solution. We anticipate this model will accelerate predictions for high-throughput screening to quickly identify relevant reactions in solution, and our data set will serve as a benchmark for future studies.

Ultraviolet Nonlinear Optical Single Crystals of A Three‐Dimensional Chiral Covalent Framework Containing Te−O−B−O Bonds

AbstractExtending covalent organic frameworks (COFs) into crystalline carbon‐free covalent backbones is an important strategy to endow these materials with more exotic functions. Integrating metal‐free inorganic and organic components into one covalent framework is an effective way to address the issue of poor thermal/solvent stability in the field of nonlinear optics (NLO). However, constructing such structures is very challenging. Here, we linked 3‐connected nods (BO3) and 2‐connected organic building blocks (Te(Ph)2) together to produce colorless single crystals (size up to 400 μm) of a three‐dimensional (3D) chiral covalent framework (CityU‐22). The single‐crystal X‐ray diffraction (SCXRD) analysis reveals that CityU‐22 has a non‐carbon Te−O−B−O bond‐based network with the srs topology. The chiral CityU‐22 displays good stability under the treatment of different common solvents or heat (the decomposition temperature above 300 °C). Due to its non‐π‐conjugated backbone (−Te−O−B−O−), CityU‐22 shows an ultraviolet NLO behavior with a second‐harmonic generation (SHG) response similar to KH2PO4 (KDP).

Ultraviolet Nonlinear Optical Single Crystals of A Three-Dimensional Chiral Covalent Framework Containing Te-O-B-O Bonds.

Extending covalent organic frameworks (COFs) into crystalline carbon-free covalent backbones is an important strategy to endow these materials with more exotic functions. Integrating metal-free inorganic and organic components into one covalent framework is an effective way to address the issue of poor thermal/solvent stability in the field of nonlinear optics (NLO). However, constructing such structures is very challenging. Here, we linked 3-connected nods (BO3) and 2-connected organic building blocks (Te(Ph)2) together to produce colorless single crystals (size up to 400 µm) of a three-dimensional (3D) chiral covalent framework (CityU-22). The single-crystal X-ray diffraction (SCXRD) analysis reveals that CityU-22 has a non-carbon Te-O-B-O bond-based network with the srs topology. The chiral CityU-22 displays good stability under the treatment of different common solvents or heat (the decomposition temperature above 300 °C). Due to its non-π-conjugated backbone (-Te-O-B-O-), CityU-22 shows an ultraviolet NLO behavior with a second-harmonic generation (SHG) response similar to KH2PO4 (KDP).

Green Solvent γ-Valerolactone (GVL) Facilitates Photocatalytic C-H Bond Activation.

Solvents can significantly influence chemical reactions in condensed phases. Their critical properties are increasingly recognized in various research domains such as organic synthesis and biomass valorization. However, in semiconductor photocatalysis, solvents are primarily viewed as mediums for dissolving and diffusing substances, with their potential beneficial effects on photocatalytic conversions often overlooked. Additionally, common photocatalysis solvents like acetonitrile (ACN) pose serious safety and environmental concerns. In this study, we demonstrate that novel and safe green solvents, such as γ-valerolactone (GVL), can significantly enhance the performance of semiconductor photocatalysis for C-H bond activation. Non-specific solvent-solute interactions are the primary contributors to increased photocatalytic activity in the self-coupling of benzylic compounds. Specifically, GVL's large dielectric constant and high refractive index lower the energy barrier for the rate-determining C-H bond activation step, facilitating a faster coupling reaction. The versatility of GVL is further demonstrated in reactions with multiple reagents and in various oxidation and reduction photocatalytic systems beyond classic C-H bond activation. This work not only pioneers the use of green solvents but also provides comprehensive insights for proper solvent selection in semiconductor photocatalysis.

Green Solvent γ‐Valerolactone (GVL) Facilitates Photocatalytic C−H Bond Activation

AbstractSolvents can significantly influence chemical reactions in condensed phases. Their critical properties are increasingly recognized in various research domains such as organic synthesis and biomass valorization. However, in semiconductor photocatalysis, solvents are primarily viewed as mediums for dissolving and diffusing substances, with their potential beneficial effects on photocatalytic conversions often overlooked. Additionally, common photocatalysis solvents like acetonitrile (ACN) pose serious safety and environmental concerns. In this study, we demonstrate that novel and safe green solvents, such as γ‐valerolactone (GVL), can significantly enhance the performance of semiconductor photocatalysis for C−H bond activation. Non‐specific solvent‐solute interactions are the primary contributors to increased photocatalytic activity in the self‐coupling of benzylic compounds. Specifically, GVL′s large dielectric constant and high refractive index lower the energy barrier for the rate‐determining C−H bond activation step, facilitating a faster coupling reaction. The versatility of GVL is further demonstrated in reactions with multiple reagents and in various oxidation and reduction photocatalytic systems beyond classic C−H bond activation. This work not only pioneers the use of green solvents but also provides comprehensive insights for proper solvent selection in semiconductor photocatalysis.

Exploring the Effects of Optically Active Solvents in Chiral Chromatography on Polysaccharide-Based Columns.

Exploring the effectiveness of optically active solvents as mobile-phase modifiers in chiral liquid chromatography (LC) can offer an additional new tool to tune the chiral selectivity. Hence, the potential of l-ethyl lactate (LEL), a biobased solvent of this nature, was explored for its distinctive interactions with both the mobile phase and analytes, as anticipated from its chiral nature. The findings reveal that LEL provides distinct selectivity compared to commonly used modifiers in chiral LC. Reversed-phase LC (RPLC)-type chiral separations were therefore compared under various conditions whereby LEL was partially or completely replacing common achiral solvents such as acetonitrile (ACN) and methanol (MeOH). An increase in chiral resolution was obtained in 8 of 16 test compounds. For 5 of them a decrease was obtained, and 3 test solutes did not offer satisfactory results under any of the tested conditions on the polysaccharide columns. When LEL was combined with methanol instead of ACN, worse results were obtained, presumably due to its protic nature. Moreover, LEL demonstrates excellent compatibility with salt additives and is fully miscible with aqueous phases. Interestingly, a steeper increase in chiral resolution is observed for LEL, as compared to ACN at lower temperatures. While LEL is somewhat hindered by its higher UV absorbance, it paves the way toward more simplified chiral screening platforms, whereby chiral solutions can be found for fewer columns and greener solvents such as LEL are incorporated. Finally, to elucidate the impact of chiral interactions between the solvent and analytes, the influence of d-ethyl lactate (DEL) was compared with that of LEL. The results revealed different interactions between the stereoisomers of ethyl lactate (EL) and chiral analytes, demonstrating an influence of optically active solvents on enantioseparations.

Novel mixed matrix membranes containing calixarene for enhanced CO2/N2 separation

Calixarene possessing advantages of small intrinsic cavity size, small particle dimension, and facile dispersion or dissolution in common solvents, is promising filler candidates in mixed matrix membranes (MMMs) for gas separation. Herein, the supramolecular C-propylpyrogallol[4]arene (PgC3) was successfully synthesized via a phenolic resin condensation reaction. It was then incorporated into a polyether-polyamide block copolymer (Pebax-1657) to prepare mixed matrix membranes (MMMs) with varying PgC3 loadings for CO2/N2 separation. The formation of hydrogen bonds between PgC3 and Pebax facilitated the uniform dispersion of PgC3 within the polymer matrix, enhancing interfacial compatibility. The incorporation of PgC3 significantly enhanced the CO2/N2 selectivity of the Pebax while preserving its permeability. The 1 wt% PgC3/Pebax MMMs performs the best CO2/N2 selectivity of 58.6, substantially higher than that of pristine Pebax membrane (32.4). This improvement can be attributed to the strong affinity between the abundant –OH groups in PgC3 and CO2 molecules. Moreover, the PgC3/Pebax MMMs exhibited exceptional stability under operating pressures of up to 5 bar, maintaining its performance consistently throughout a demanding100-hour test. The good separation performance together with the excellent stability enables PgC3 a promising filler in MMMs for CO2/N2 or other gas separations.

Fully Bio-Based Blends of Poly (Pentamethylene Furanoate) and Poly (Hexamethylene Furanoate) for Sustainable and Flexible Packaging.

In the present study, bio-based polymeric blends have been prepared for applications in the field of sustainable food packaging, starting from two furan-based homopolymers, poly(hexamethylene 2,5-furanoate) (PHF) and poly(pentamethylene 2,5-furanoate) (PPeF). PHF and PPeF were synthesized by two-step melt polycondensation-a solvent-free synthetic strategy-and then binary physical mixtures, PHF/PPeF, with different weight compositions were prepared by dissolution in a common solvent. The blends were processed into compression-moulded films, and molecular, morphological, structural, thermal, and mechanical characterizations were subsequently carried out. Blending did not negatively affect the thermal stability of the parent homopolymers, and good compatibility between them was observed. This strategy also allowed for the modulation of the chain rigidity as well as of the crystallinity, simply by acting on the relative weight amount of the homopolymers. From a mechanical point of view, the presence of PPeF led to a reduction in stiffness and an increase in the elongation at break, obtaining materials with an elastomeric behaviour. Evaluation of the gas barrier properties confirmed that the good barrier properties of PHF were preserved by blending. Finally, lab-scale composting tests confirmed a greater weight loss of the mixtures with respect to the PHF homopolymer.

Consolidating Lime Mortar with Nanolime: The Effect of the Ethanol:Water Ratio

ABSTRACT Over the last twenty years, more research has been conducted on the application of nanolime as a consolidant. However, a limitation in consolidation with nanolime is the back-migration of the product to the absorption surface during the drying phase, resulting in insufficient product deposition in depth. In this paper, a solvent composition is adapted to the substrate properties to examine the theory that a nanolime with low kinetic stability should be applied to prevent back-migration to the absorption surface for a substrate with large pore size. The common solvent composition of 100% ethanol has a kinetic stability considered too high. Nanolime dispersions (CaLoSiL® E 20 g/L) with different ethanol:water (100:0, 95:5, 90:10, 80:20) ratios were tested on lime mortar samples. The treated samples were subjected to several test methods to evaluate the effectiveness of the consolidation treatment. After comparing the results, the theoretical propositions were substantiated: a back-migration was noticeable in samples treated with the nanolime containing 100% ethanol, while no back-migration was observed in the other solvent compositions. Samples treated with a nanolime dispersion with the addition of 10% deionised water showed promising results regarding mechanical strength, product deposition over the entire depth profile of the sample, and porosity properties.

Refractive index in the JUNO liquid scintillator

In the field of rare event physics, it is common to have huge masses of organic liquid scintillator as detection medium. In particular, they are widely used to study neutrino properties or astrophysical neutrinos. Thanks to its safety properties (such as low toxicity and high flash point) and easy scalability, linear alkyl benzene is the most common solvent used to produce liquid scintillators for large mass experiments. The knowledge of the refractive index is a pivotal point to understand the detector response, as this quantity (and its wavelength dependence) affects the Cherenkov radiation and photon propagation in the medium. In this paper, we report the measurement of the refractive index of the JUNO liquid scintillator between 260–1064 nm performed with two different methods to cover wide range of refractive index (an ellipsometer and a refractometer), with a sub percent level precision. In addition, we used an interferometer to measure the group velocity in the JUNO liquid scintillator and verify the expected value derived from the refractive index measurements.

(Invited) 2D Semiconductors from Spin-on Molecular Chemistries for Direct Large-Scale Integration

In this talk, I will discuss our recent developments centered on a process to produce fully soluble solutions from a unique molecular chemistry. This enables the creation of wafer-scale monolayers of MoS2, a prominent 2D semiconductor for logic and memory devices. This molecule can be dissolved in common solvents and spin-coated onto various substrates, including crystalline substrates, printed electrodes, and polymers. It can also be integrated into gate-all-around (GAA) 3D transistor structures for logic devices. Our method of rapidly synthesizing large-area MoS2 films, particularly in monolayer form via spin-coating, represents a novelty, as it hasn't been demonstrated previously with a single-source chemistry. This advancement is a significant step toward scalable synthesis of wafer-scale 2D semiconductor thin films, eliminating the need for post-growth wafer transfer techniques, a requirement with films grown by chemical vapor deposition (CVD) methods. Our fabrication process highlights the potential of using a single-source chemical precursor to develop monolayer 2D semiconductors that exhibit commendable transport characteristics and optical properties, which enhance with rising crystallization temperatures. Consequently, it holds promise as a semiconductor for microelectronic transistor channels in both back-end-of-line (BEOL) and front-end-of-line (FEOL) architectures.