Methyl Ether Research Articles

Comparative Study of Plant‐Based Antioxidants on the Stability of Soybean and Beef Tallow Biodiesels

ABSTRACTBiodiesel is a renewable alternative fuel, but its oxidative instability reduces quality and performance over time. This study explicitly aimed to investigate the efficacy of natural antioxidants—acerola, soursop, mango, and pitanga leaves—and compare their performance to the synthetic antioxidant butylated hydroxytoluene (BHT) in enhancing the thermooxidative stability of soybean ethyl and bovine tallow methyl biodiesels. Biodiesels were synthesized and stored under controlled conditions (ambient and 60°C) for up to 1848 h. Analytical results showed that biodiesel treated with BHT maintained acidity index (AI) values below 0.5 mg KOH/g after 1176 h, while untreated biodiesel exceeded 1.0 mg KOH/g within 504 h. Kinematic viscosity for BHT‐treated samples remained under the acceptable limit of 6.0 mm²/s for 1176 h, compared with untreated biodiesel, which surpassed the limit at 504 h. Natural antioxidants exhibited varying degrees of efficacy, with soursop and pitanga extracts achieving 35%–50% improvements in oxidative stability compared with untreated biodiesel. Thermogravimetric analysis indicated that natural additives delayed the onset of degradation temperatures by 10°C–15°C. These findings demonstrate that plant‐based antioxidants significantly enhance biodiesel stability, offering up to 70% of the effectiveness of BHT, and highlight their potential as sustainable alternatives for improving biodiesel quality.

Versatile and Controlled Synthesis of Degradable, Water-Soluble Bottlebrush Polymers with Poly(disulfide) Backbones Derived from α-Lipoic Acid.

Bottlebrush (BB) polymers, with their densely grafted side chains and unique architecture, are highly advantageous for drug delivery due to their high functional group density for drug conjugation, unimolecular nature, and enhanced biodistribution properties. These attributes enable extended blood circulation half-life, improved tumor tissue penetration, and high tumoral drug accumulation. However, the typically nondegradable, all-carbon backbones of most BB polymers limit their suitability for applications requiring controlled clearance and biodegradability. To address this, we developed degradable BB polymers with poly(disulfide) backbones synthesized via reversible addition-fragmentation chain transfer (RAFT) copolymerization of α-lipoic acid (LA), a renewable and readily available compound, with acrylate-based inimers. These copolymers feature degradable backbones and initiating sites for subsequent BB synthesis. Using an atom transfer radical polymerization (ATRP) grafting-from methodology, we synthesized BB polymers with relatively low dispersities (Đ = 1.30-1.53), high backbone degrees of polymerization (DPbb), and high molar masses (Mn,MALS = 650-2700 kg/mol). The easily cleavable disulfide bonds enabled backbone degradation under mild reducing conditions. Beyond hydrophilic BB with tri(ethylene glycol) methyl ether acrylate (TEGA) side chains, we synthesized BB with cationic, anionic, and zwitterionic side chains, demonstrating broad monomer compatibility. This scalable approach produces water-soluble, degradable BB polymers with tunable architectures and predictable molecular weights. By addressing the need for degradability in BB polymers, this work advances their potential for drug delivery, offering enhanced functionality, biocompatibility, and sustainability.

Synthesis of Polyether Ester Plasticizer and Its Application Performance in Hydrogenated Nitrile Butadiene Rubber

ABSTRACTFour polyether ester plasticizers containing both ester groups and ether bonds were synthesized using 1,4‐butanediol, adipic acid, and alkyl ether alcohols as raw materials. By varying the type of end‐capping alcohol ether, the following plasticizers were prepared: poly (butylene adipate dibutyl ether) (PBADBE), poly (butylene adipate butyl ether) (PBABE), poly (butylene adipate dimethyl ether) (PBADME), and poly (butylene adipate methyl ether) (PBAME). These plasticizers were characterized by Fourier transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance spectroscopy (1H‐NMR), and thermogravimetric (TG) analysis. Furthermore, their differences in cold resistance, heat resistance, and physical‐mechanical properties in hydrogenated nitrile‐butadiene rubber (HNBR) were investigated. The results showed that among the rubber compounds containing the four polyether‐ester plasticizers, the compound with PBADME demonstrated superior heat resistance and low‐temperature performance. Specifically, the PBADME‐containing compound exhibited a TR10 temperature of −39.9°C and a brittleness temperature of −54°C. This significantly broadened the operating temperature range of the plasticizer, making it suitable for applications requiring both high‐temperature and low‐temperature performance.

Methoxyl-Containing Hyper-Crosslinked Polymer from Largely Bio-Based Biphenyl Methyl Ether and Its Application in Lithium-Sulfur Battery

Methoxyl-Containing Hyper-Crosslinked Polymer from Largely Bio-Based Biphenyl Methyl Ether and Its Application in Lithium-Sulfur Battery

Genetic Diversity Analysis and Comprehensive Evaluation of “M82” in EMS-Mutagenized Tomato

Background: Ethyl methyl sulfonate (EMS) mutagenesis is widely used because of its advantages of inducing point mutations and no need for genetic transformation. To identify germplasm resources of processed tomatoes with superior comprehensive traits suitable for cultivation in Xinjiang. Methods: In this study, tomato seeds were treated with 2% EMS reagent for 12 h, 21 quality traits and 20 quantitative traits of 33 processed tomatoes derived from EMS-mutagenized“M82”were evaluated. Results: The results indicated that for traits such as hypocotyl color, growth habit, plant type, leaf type, and leaf shape, the range of quantitative trait variation was 8.45–37.25%, with a genetic diversity index ranging from 1.25 to 2.07. Conclusions: Cluster analysis of quantitative traits categorized the 33 EMS-mutagenized “M82” processed tomato resources into five groups: Group I contained 22 robust germplasm samples; Group II consisted of a single potential high-quality germplasm; Group III comprised five germplasm with a small and extreme plant type; Group IV included four high-yield germplasm; and Group V represented one moderate, conventional germplasm. Raw data from 15 quantitative traits across the 33 accessions were standardized using the “extreme method” to extract six comprehensive factors. The top 10 germplasm resources based on the comprehensive score were 76, 137, 97, 102, 19, 104, 21, 108, 17, and 147. It provides some theoretical basis for realizing the high-yield and high-quality cultivation and variety breeding of processed tomatoes in Xinjiang.

Selective Borylation of C(sp3)−H Bond of Methyl Ethers Catalyzed by Iron Complexes Bearing Anionic Benzene‐Based PCP‐Pincer Ligands

AbstractHighly selective catalytic C(sp3)−H borylation of methoxy groups has been achieved using newly synthesized iron complexes bearing benzene‐based PCP‐type pincer ligands as catalysts. Reactions of various aryl and alkyl methyl ethers as substrates with bis(pinacolato)diboron under mild reaction conditions proceeded to afford the corresponding methoxy borylated products in good to high yields. A successful example of the iron‐catalyzed C(sp3)−H borylation of a methylene group of tetrahydrofuran (THF) was also presented. A plausible reaction pathway is proposed based on the experimental result of some stoichiometric reactions and DFT calculations on a model reaction, where iron‐boryl and ‐alkyl complexes may work as key intermediates.

Elucidation of α-glucosidase inhibitory activity and UHPLC-ESI-QTOF-MS based metabolic profiling of endophytic fungi Alternaria alternata BRN05 isolated from seeds of Swietenia macrophylla king

There is a growing demand for new diabetes drugs with fewer side effects to replace current medications known for their adverse effects. Inhibition of α-glucosidase responsible for postprandial hyperglycemia among diabetes patients is a promising strategy for managing the disease. This study aims to explore and identify novel bioactive metabolites with anti-diabetes potential from Alternaria alternata BRN05, an endophytic fungus isolated from a well-known medicinal plant Swietenia macrophylla King. Ethyl acetate extracts of Alternaria alternata BRN05 grown in full-strength (EFS) and quarter-strength (EQS) media, respectively were evaluated for their α-glucosidase inhibitory activities. Based on IC50 values, EQS exhibited significantly greater inhibitory activity (0.01482 ± 1.809 mg/mL) as compared to EFS (1.16 ± 0.173 mg/mL) as well as acarbose control (0.494 ± 0.009 mg/mL). EFS and EQS were subjected to metabolic profiling using Ultra-High-Performance Liquid Chromatography - Electrospray Ionization - Quadrupole Time-of-Flight Mass Spectrometry (UHPLC-ESI-QTOF-MS). A total of nineteen metabolites from EFS and twenty from EQS were tentatively identified based on MS/MS fragmentation. Molecular docking analysis revealed that twelve among these exhibited greater binding energies than that of acarbose (-6.6 kcal/mol). Molecular Dynamics (MD) simulations of 3’,4’,7-trihydroxyisoflavanone (THF) and alternariol 9-methyl ether (AME) from EQS, exhibiting high binding energies (-7.5 and -7 kcal/mol, respectively), were performed to investigate their interactions with human intestinal α-glucosidase. Results suggest THF possesses strong inhibitory potential, making it a promising candidate for diabetes management.

Spatial Scale Matters: Hydrolysis of Aryl Methyl Ethers over Zeolites.

The local environment of the active site, such as the confinement of hydronium ions within zeolite pores, significantly influences catalytic turnover, similar to enzyme functionality. This study explores these effects in the hydrolysis of guaiacols─lignin-derived compounds─over zeolites in water. In addition to the interesting catechol products, this reaction is advantageous for study due to its bimolecular hydrolysis pathway, which involves a single energy barrier and no intermediates, simplifying kinetic studies and result interpretation. As in alcohol dehydration, hydronium ions show enhanced activity in ether hydrolysis due to undercoordination and increased electrophilicity when confined within zeolite pores, compared to bulk water. In addition, a volcano-shaped relationship between hydronium ion activity and Brønsted acid density was observed. However, unlike alcohol dehydration, this activity distribution cannot be attributed to variations in ionic strength within the pores, as the rate-determining step in the hydrolysis of guaiacols involves the attack of a neutral water molecule, unaffected by ionic strength. Instead, a detailed transition state analysis revealed a significant thermodynamic energy compensation effect, driven by the spatial organization of the transition state. This organization is influenced by the available reaction space, the interaction between the reacting species and the zeolite environment, leading to the volcano-shaped dependence. This phenomenon also explains the unusual reactivity order of the 4-R-guaiacol derivatives (R = H, Me, Et, Pr) with zeolite catalysis, extending beyond the traditional steric and electronic effects to provide a deeper understanding of reactant reactivity. The work concludes that the critical spatial parameters for fast ether hydrolysis─resulting in the highest hydronium activity─are determined by a combination of zeolite properties (topology and acid density) and reactant size.

Selective hydrogenation of anisole over Pt/SBA-15 catalysts: Effect of Pt loading on catalytic efficiency

Abstract Pt catalysts (0.1–2 wt.% of platinum) supported on SBA-15 were used for the selective hydrogenation of the aromatic ring of anisole with the formation of cyclohexyl methyl ether product. The catalysts were characterized by N2 physisorption, UV–vis diffuse reflectance spectroscopy, powder X-ray diffraction, and scanning and transmission electron microscopies. The reaction progress and the impact of Pt loading in the catalysts were analyzed by gas chromatography. All the catalysts demonstrated high catalytic activity for the hydrogenation of anisole to cyclohexyl methyl ether (CME), reaching 90–98% anisole conversion at 6-h reaction time with near 90% selectivity to CME (280 °C, 6.9 MPa total pressure). An increase in the Pt content led to a slight decrease in the selectivity to CME due to its transformation to cyclohexane. 1%Pt/SBA-15 catalyst was tested in three repeated catalytic cycles showing high stability and preservation of Pt nanoparticle dispersion. Graphical abstract

Sustainable biodegradation of malachite green dye by novel non-pathogenic Pseudomonas aeruginosa ED24.

Sustainable management of textile industrial wastewater is one of the severe challenges in the current regime. It has been reported that each year huge amount of textile industry discharge especially the dye released into the environment without pre-treatment that adversely affect the human health and plant productivity. In the present study, different bacterial isolates had been isolated from the industrial effluents and investigated for their bioremediation potential against the malachite green (MG) dye, a major pollutant of textile industries. The biochemical and molecular characterization of the bacterial strain showed the resemblance of most potent strain ED24 as Pseudomonas aeruginosa, which showed effective bioremediation potential against the MG dye. During response surface analysis (RSM), best MG degradation conditions have been observed at pH 7.0, 37°C, 48h, and 200mg/L dye concentration, with highest degradation efficiency of 96.56 ± 0.8622 percent. Subsequently, supplementing various carbon and nitrogen sources increases MG decolorization by 1 to 2%, with beef extract (97.23%), sodium nitrate (97.46%), and maltose (98.67%). FT-IR results revealed the disappearance of distinct peaks, namely, 3328.275cm-1, 2102.842cm-1, 1101.140cm-1,and 559.04cm-1 from MG, and the formation of major intermediate compounds like leucomalachite green, benzoic acid, diacetamide, benzeneacetic acid, hexyl ester, ethyl 4-acetoxy butanoate, butanoic acid, and 2-methyl in GC-MS analysis of degraded dye sample confirms the biodegradation by bacterial strain ED24. The phytotoxicity studies on mung bean seeds confirmed MG dye toxicity reduction up to 67.53%, 54.16%, and 67.53% in biomass accumulation, root, and shoot lengths, respectively. Also, the microbial toxicity of MG was completely reduced on soil microflora Bacillus flexus, Stenotrophomonas maltophilia, Escherichia coli, Staphylococcus aureus, and Alternaria spp.The dual mitigation, both in microbial and plant systems, indicates the strong remediation potential of P. aeruginosa ED24 to break down MG dye ecologically sustainably.

When a Small Amount of Comonomer Is Enough: Tailoring the Critical Solution Temperature of LCST-Type Thermoresponsive Random Copolymers by PEG Methyl Ether Methacrylate with 1100 g/mol Molecular Weight.

Tuning the critical solution temperature (CST) of thermoresponsive polymers is essential to exploit their immense potential in various applications. In the present study, the effect of PEG-methyl ether methacrylate with a higher molecular weight of 1100 g/mol (mPEGMA1100) as a comonomer was investigated for its suitability for the CST adjustment of LCST-type polymers. Accordingly, a library of mPEGMA1100-based copolymers was established with varying compositions (XmPEGMA1100) using four main comonomers, namely di(ethylene glycol) ethyl ether acrylate, N-isopropyl acrylamide and methacrylamide, and mPEGMA300, with different CST values (cloud points, TCP, and clearing points, TCL, by turbidimetry). It was found that less than 20 mol% of the mPEGMA1100 in the copolymers is practically sufficient for tuning the CST in the entire measurable temperature range, i.e., up to 100 °C, regardless of the CST of the homopolymer of the main comonomer (CST0). Moreover, a predictive asymptotic model was developed based on the measured CST values, which strikingly revealed that the CSTs of mPEGMA1100-containing copolymers depend only on the two main parameters of these copolymers, XmPEGMA1100 and the CST of the homopolymer of the main comonomer (CST0), that is, CST = f(CST0, XmPEGMA1100). The revealed two-parameter relationship defines a surface in 3D plotting, and it is applicable to determine the CST of copolymers in advance for a given composition or to define the suitable composition for a required CST value. These unprecedented results on the dependence of CSTs on two major well-defined parameters enable to design a variety of novel macromolecular structures with tailored thermoresponsive properties.

Biorefinery-inspired, two-step valorization strategy to manage plant-based recalcitrant organic waste, involving solvent extraction, and fermentation with Bacillus clausii-a proof of concept study.

Approximately 40-50% of municipal solid waste is organic and causing biogenic malodor and infections, due to inefficient treatment methods. Biorefinery-based bioremediation and valorization is in vogue against these conventional strategies since it combines unit operations for better efficiency and productivity. Deriving inspiration, the proposed strategy puts together a unique and compatible combination of processes. This novel two-step valorization workflow involves the extraction of small molecules using organic solvents, and fermentation of resulting denatured residues (increased biodegradability or decreased recalcitrance) of reduced microbial load. The extraction step also doubles up as a sterilization event, with different solvents (petroleum ether, chloroform, ethyl methyl ketone and methanol) exhibiting varied efficiency, methanol and ethyl methyl ketone being the most effective. Different recalcitrant plant organic wastes resulting from four plants (Cocos nucifera, Allium cepa, Artocarpus hirsutus and Swietenia mahagoni) were used as feedstocks in the preliminary exploratory study using chosen pathogenic bacteria. Onion peel (Allium cepa) ethyl methyl ketone extract was chosen for further studies, as it inhibits Salmonella enterica, which is associated with infection and malodour (due to biogenic H2S) in wastewater. Further, fractionation of the extract yielded quercetin and its glycoside. The onion peel residue, after solvent extraction was fortified with peptone and essential minerals to promote the growth of Bacillus clausii. Fortified post-extraction residue supported the growth better than the pre-extraction residue. The residue resultant after solvent extraction was fermented with Bacillus clausii and with release of bioactive supernatants. The concentrated supernatant showed significant inhibition of Salmonella enterica and Shigella dysenteriae. Additionally, all the exudates showed considerable inhibition in H2S production, respectively.

AmelOBP4: an antenna-specific odor-binding protein gene required for olfactory behavior in the honey bee (Apis mellifera)

BackgroundOdorant binding proteins (OBPs) initiate the process of odorant perception. Numerous investigations have demonstrated that OBPs bind a broad variety of chemicals and are more likely to carry pheromones or odor molecules with high binding affinities. However, few studies have investigated its effects on insect behavior. Previously, we found that AmelOBP4 has a significantly higher expression in the heads of foragers than that of nurses regardless of their ages, revealing its importance in foraging behaviour of the honey bee. RNA interference (RNAi) is the induction of sequence specific gene silencing by double-stranded RNA (dsRNA), it is a powerful tool that makes gene inactivation possible in organisms that were not amenable to genetic analysis before.ResultsIn this study, we found that AmelOBP4 had high expression levels in the antennae of both nurses and foragers, and could be successfully inhibited by feeding double stranded RNA of AmelOBP4 (dsAmelOBP4). Foragers with inhibited AmelOBP4 showed significantly lower sugar responsiveness than control bees, and also significantly reduced EAG response to plant volatiles of nonanal, linalool and 1-Octen-3ol. On the other hand, nurses with inhibited AmelOBP4 showed significantly reduced EAG response to brood pheromone of ethyl oleate, methyl linoleate, methyl palmitate and β-ocimene. Finally, the Y-tube choice assay showed nurses only exhibited a significantly reduced preference to ethyl oleate, but foragers exhibited significantly reduced preference to all these three plant volatiles.ConclusionsThe findings of our study suggested that AmelOBP4 plays an important role in the odorant binding process, especially in modulating olfactory behaviour in workers. Our results provide a foundation for exploring the olfactory mechanism of Apis mellifera.

New Oxygenated Methoxy-p-Cymene Derivatives from Leopard's Bane (Doronicum columnae Ten., Asteraceae) Essential Oil: Synthesis Facilitating the Identification of Isomeric Minor Constituents in Complex Matrices.

Species of the genus Doronicum are known for their pharmacological properties and essential oils, the chemical composition of which remains inadequately studied. In this work, GC-MS analysis, synthesis, and spectral techniques (UV, IR, MS, and NMR) were employed to identify 83 constituents in the essential oil from D. columnae roots, which accounted for 98.1% of the total GC-peak area. The major components were thymyl isobutyrate (32.8%) and thymyl 2-methylbutyrate (22.8%), while the minor constituents were methoxy-p-cymene derivatives. Six new natural products were identified through synthesis, GC co-injection experiments and spectral characterization, including esters (isobutyrate, 2-methylbutyrate, and/or isovalerate) of 2-methoxycuminol, 6-methoxythymol, and 6-hydroxythymyl methyl ether, as well as methyl 3-methoxycuminate. Their identification was made possible by synthesis efforts, as isolating pure compounds was impracticable because of their low abundance and the overall structural similarity within the highly complex mixture that was the essential oil.

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.

High-Pressure Pathway in the Two-Stage Synthesis of 5-Amino-3-Hydroxy-1-Phenyl-1H-Pyrazole

Abstract: 5-amino-3-hydroxy-1-phenyl-1H-pyrazol and 3-amino-5-hydroxy-1-phenyl-1H-pyrazol are widely used as synthons in organic and pharmaceutical chemistry. We developed a high-yield synthesis method for 5-amino-3-hydroxy-1-phenyl-1H-pyrazol using high-pressure and base catalysis, achieving up to 80% yield. This method significantly outperforms existing techniques, which yield no more than 39%. The synthesis was performed at pressures up to 10 katm, both in solvent-free conditions and in the presence of solvents, such as methanol, ethanol, toluene, tert-butyl methyl ether, and 1,4-dioxane. Thermodynamic parameters of possible paths were calculated using the SMD-M06- 2X/MG3S method. Applying high pressure (7 katm) enables the solvent-free and catalyst-free synthesis of 2-cyano-N'-phenylacetohydrazide with a yield of 96%. This compound can subsequently be converted into 5-amino-3-hydroxy-1-phenyl-1H-pyrazol with yields of up to 90% using base catalysis. Additionally, the reaction pathways of phenylhydrazine with ethyl cyanoacetate and its anion have been explored. These pathways are discussed in terms of thermodynamic potentials calculated using the SMD-M06-2X/MG3S method. High pressure significantly accelerates the reaction between phenylhydrazine and ethyl cyanoacetate, leading to the formation of 2-cyano-N'-phenylacetohydrazide. This intermediate can then be easily converted into 5-amino-3-hydroxy-1-phenyl-1H-pyrazol. Under neutral conditions, the most favorable reaction pathway involves the attack of the terminal nitrogen of phenylhydrazine on the carbonyl group. In the case of the ethyl cyanoacetate anion, the attack also targets the carbonyl group, but occurs via the phenyl-substituted nitrogen.

Precise Preparation of Size-Uniform Two-Dimensional Platelet Micelles Through Crystallization-Assisted Rapid Microphase Separation Using All-Bottlebrush-Type Block Copolymers with Crystalline Side Chains.

Polymer nanoparticles with low curvature, especially two-dimensional (2D) soft materials, are rich in functions and outstanding properties and have received extensive attention. Crystallization-driven self-assembly (CDSA) of linear semicrystalline block copolymers is currently a common method of constructing 2D platelets of uniform size. Although accompanied by high controllability, this CDSA method usually and inevitably requires a longer aging time and lower assembly concentration, limiting the large-scale preparation of nanoaggregates. In this study, a series of all-bottlebrush-type block copolymers, poly(octadecyl acrylate)-block-poly(oligoethylene glycol methyl ether methacrylate)s are prepared by living polymerization. Driven by the synergistic crystallization of crystalline side chains and the rapid microphase separation of bottlebrush topology, these polymers can assemble into uniform 2D circular platelet micelles in a few minutes, without being affected by a high assembly concentration. In this process, epitaxial growth of the bottlebrush molecules proceeds with rigid cylindrical molecular conformation at the micelle crystallization sites and eventually provides a sandwich-type micelle according to a head-to-head stacking mode. This is explained as a "crystallization-assisted rapid microphase separation" mechanism. The micelle structures are affected by the assembly solvent and temperature, the size of which shows a linear dependence on the assembly temperature below the melting point of the crystalline block, which can be used to precisely control the morphology of these 2D platelets. This study establishes an efficient and rapid method to prepare 2D polymer nanosoft materials, which are promising candidates for further development, preparation, and application of various nanomaterials.

Reconciliation of the vapor pressure temperature dependences of poorly studied substances. Part I: Individual compounds

Determination of the thermodynamic parameters of vaporization requires expensive equipment and significant financial and time expenditure. On the other hand, obtaining these characteristics for the permanently growing number of organic substances is impossible. In this work, we propose a simple procedure for derivation of the vaporization characteristics from the independent measurements of the reduced and normal pressure boiling points that are often obtained by organic chemists during purification procedures and collected in the databases. The consistency of such p-T measurements was discussed, and expected errors of derived vaporization enthalpies and saturated vapor pressures were evaluated. Applying the methodology proposed, we derived the vaporization characteristics of six compounds: ethyl 4-chlorobutanoate, benzyl methyl ether, 4-methylanisole, ethyl 2-acetyloxypropanoate, 3,3-dimethyl-allyl chloride and ethyl cyclohexanecarboxylate. As a result, this methodology promises obtaining previously unknown vaporization characteristics of hundreds of molecules in a short time without performing the additional measurements. The simplicity of the procedure proposed and existence the data needed in the electronic databases makes possible an automatization of this approach.

Crowding effects on the structure and rheology of ultrasoft PNIPAM-PEGMA copolymer microgels.

We investigate the link between the internal microstructure of poly(N-isopropylacrylamide)-poly(ethylene glycol) methyl ether methacrylate (PNIPAM-PEGMA) microgels, their bulk moduli and the rheological response and structural arrangement in dense suspensions. The low degree of crosslinking combined with the increased hydrophilicity induced by the presence of PEGMA results in a diffuse, star-like density profile of the particle and very low values of the bulk modulus in dilute conditions, as determined by small angle neutron scattering (SANS). The ultrasoft nature of the particle is reflected in the changes of the structural arrangement in dense suspensions, which evidence a strong deswelling and a sharp rise of the bulk modulus at moderate packing fractions. At larger packings the single particle morphology and softness saturate, and we observe a structural transition from a dispersion-like to a hydrogel-like behavior. The transition is also reflected in the rheological response in the form of a two-step yielding at large packing fractions, characteristic of systems in which a network structure is present. Our results demonstrate that a knowledge of the internal structure and mechanics of individual microgels is needed to determine and tune the properties of dense suspensions, and optimize their response for applications in biomedicine and as filtration systems.

Investigation of chemical kinetic models for electrolyte solvent vapors released from thermal runaway lithium-ion batteries

The vent gas generated from electrolyte decomposition during thermal runaway is the primary cause of fires in lithium-ion batteries. Accurate chemical kinetic models contribute to a deeper understanding of the rapid redox and reaction kinetics during the thermal runaway process in lithium-ion batteries, laying the foundation for the design of safer storage batteries. This study conducted combustion experiments on ethyl methyl carbonate (EMC) and optimized a comprehensive chemical kinetic model for linear carbonate esters (LCEs). The laminar burning velocity (LBV) of EMC/air was measured via a 36-l constant volume combustion chamber at an initial temperature of 373 ± 2 K, initial pressure of 0.7–1.6 atm, and equivalence ratio of 0.6–1.6. Here, we present a novel method to optimize chemical kinetic models of LCEs. The method accurately screens the candidate reactions in the seed kinetic model through global sensitivity analysis and perturbation testing. The genetic algorithm was subsequently used to optimize the rates of candidate reactions in the new kinetic model within a small range (0.2–5 times the original values). The optimized model (Modelopt) enhanced the predictive accuracy of LBV and IDT by 28.4 % and 43.1 %, respectively, and reduced the prediction errors for EMC and DMC pyrolysis while retaining the prediction accuracy of DEC pyrolysis. Finally, experimental data outside of the optimization procedure were used to further validate the applicability of Modelopt.