Carbon Chain Length Research Articles

Production of bio-crude from co-pyrolysis of oil shale and peanut shell over semi-coke supported Ni catalyst

Bio-crude producted from the co-pyrolysis of oil shale and peanut shell over a Ni-based catalyst supported on semi-coke was investigated in a vertical double-temperature zone fixed bed reactor. The effect of Ni species loading on the characteristics of bio-crude was evaluated. Results indicated that the effective H/C and calorific value of bio-crude gradually increased and the average carbon chain length gradually decreased with the increase of Ni species loading. The average carbon chain length decreased from 17.54 to 12.61 when the Ni loading was 9 %. An analysis of liquid product components indicated that the presence of the catalyst promoted the combination of small molecular side chains generated by oil shale fractures and active molecules generated by peanut shell thermal decomposition, increasing the generation of phenolic compounds. Furthermore, the phenolic compounds were further converted to aromatic hydrocarbons by promoting the alkylation transfer of the methoxy group to the benzene ring, demethoxylation, and dehydration reactions.

Corrosion inhibition performance of RNC-n on aluminum alloy surface in alkaline solution

The corrosion inhibition behavior of glycine surfactants with different carbon chain lengths (RNC-n, n = 8, 12, 14) of AA2024-T3 aluminum alloy in 0.01 mol·L−1 NaOH solution was investigated. The weight loss and electrochemical methods, XPS, SEM/EDS techniques, quantum chemical calculations, and molecular dynamics simulations were used for studying the corrosion inhibition properties, adsorption behavior, and corrosion inhibition mechanism. When the maximum solubility of 0.01 mol·L−1 was achieved, the inhibition effectiveness of RNC-8 reached 90.55 %. Both RNC-12 and RNC-14 exhibited inhibitory efficiencies of 92.81 % at 0.005 mol·L−1 and 91.83 % at 0.0005 mol·L−1. RNC-n was shown to be an anodic corrosion inhibitor, since its impact on the anodic reaction was larger than on the cathodic one. RNC-n was able to successfully adsorb on the aluminum surface and form a protective film, which hindered further corrosion damage of the aluminum by the alkaline solution. In addition, the adsorption sites of RNC-n molecules were analyzed, and it was found that the adsorption sites of the corrosion inhibitor were mainly in the carboxyl group. Therefore, this paper can provide some theoretical support for the protection of aluminum alloys against corrosion in alkaline medium.

Molecular engineering of thiophene- and pyrrole-fused core arylamine systems: Tuning redox properties, NIR spectral responsiveness and bacterial imaging applications

The thiophene- and pyrrole-fused heterocyclic compounds have garnered significant interest for their distinctive electron-rich characteristics and notable optoelectronic properties. However, the construction of high-performance systems within this class is of great challenge. Herein, we develop a series of novel dithieno[3,2-b:2′,3′-d] pyrrole (DTP) and tetrathieno[3,2-b:2′,3′-d] pyrrole (TTP) bridged arylamine compounds (DTP-C4, DTP-C12, DTP-C4-Fc, TTP-C4-OMe, TTP-C4, and TTP-C12) with varying carbon chain lengths. The pertinent experimental results reveal that this series of compounds undergo completely reversible multistep redox processes. Notably, TTP-bridged compounds TTP-C4 and TTP-C12 exhibit impressive multistep near-infrared (NIR) absorption alterations with notable color changes and electroluminescent behaviors, which are mainly attributed to the charge transfer transitions from terminal arylamine units to central bridges, as supported by theoretical calculations. Additionally, compound DTP-C4 demonstrates the ability to visually identify gram-positive and gram-negative bacteria. Therefore, this work suggests the promising electroresponsive nature of compounds TTP-C4 and TTP-C12, positioning them as excellent materials for various applications. It also provides a facile approach to constructing high-performance multifunctional luminescent materials, particularly those with strong and long-wavelength NIR absorption capabilities.

Bioconcentration of Per- and Polyfluoroalkyl Substances and Precursors in Fathead Minnow Tissues Environmentally Exposed to Aqueous Film-Forming Foam-Contaminated Waters.

Exposure to per- and polyfluoroalkyl substances (PFAS) has been associated with toxicity in wildlife and negative health effects in humans. Decades of fire training activity at Joint Base Cape Cod (MA, USA) incorporated the use of aqueous film-forming foam (AFFF), which resulted in long-term PFAS contamination of sediments, groundwater, and hydrologically connected surface waters. To explore the bioconcentration potential of PFAS in complex environmental mixtures, a mobile laboratory was established to evaluate the bioconcentration of PFAS from AFFF-impacted groundwater by flow-through design. Fathead minnows (n = 24) were exposed to PFAS in groundwater over a 21-day period and tissue-specific PFAS burdens in liver, kidney, and gonad were derived at three different time points. The ∑PFAS concentrations in groundwater increased from approximately 10,000 ng/L at day 1 to 36,000 ng/L at day 21. The relative abundance of PFAS in liver, kidney, and gonad shifted temporally from majority perfluoroalkyl sulfonamides (FASAs) to perfluoroalkyl sulfonates (PFSAs). By day 21, mean ∑PFAS concentrations in tissues displayed a predominance in the order of liver > kidney > gonad. Generally, bioconcentration factors (BCFs) for FASAs, perfluoroalkyl carboxylates (PFCAs), and fluorotelomer sulfonates (FTS) increased with degree of fluorinated carbon chain length, but this was not evident for PFSAs. Perfluorooctane sulfonamide (FOSA) displayed the highest mean BCF (8700 L/kg) in day 21 kidney. Suspect screening results revealed the presence of several perfluoroalkyl sulfinate and FASA compounds present in groundwater and in liver for which pseudo-bioconcentration factors are also reported. The bioconcentration observed for precursor compounds and PFSA derivatives detected suggests alternative pathways for terminal PFAS exposure in aquatic wildlife and humans. Environ Toxicol Chem 2024;43:1795-1806. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Predicting Odor Sensory Attributes of Unidentified Chemicals in Water Using Fragmentation Mass Spectra with Machine Learning Models.

Knowing odor sensory attributes of odorants lies at the core of odor tracking when addressing waterborne odor issues. However, experimental determination covering tens of thousands of odorants in authentic water is not pragmatic due to the complexity of odorant identification and odor evaluation. In this study, we propose the first machine learning (ML) model to predict odor perception/threshold aiming at odorants in water, which can use either molecular structure or MS2 spectra as input features. We demonstrate that model performance using MS2 spectra is nearly as good as that using unequivocal structures, both with outstanding accuracy. We particularly show the model's robustness in predicting odor sensory attributes of unidentified chemicals by using the experimentally obtained MS2 spectra from nontarget analysis on authentic water samples. Interpreting the developed models, we identify the intricate interaction of functional groups as the predominant influence factor on odor sensory attributes. We also highlight the important roles of carbon chain length, molecular weight, etc., in the inherent olfactory mechanisms. These findings streamline the odor sensory attribute prediction and are crucial advancements toward credible tracking and efficient control of off-odors in water.

Effective and selective recovery of Au(III) from WPCBs using quaternary phosphonium adsorbent synthesized by adjusting steric hindrance

With the gradual depletion of natural gold ore, waste printed circuit boards (WPCBs) have become one of the most attractive alternatives to gold ore. Here, a series of quaternary phosphonium adsorbents with a large size were successfully synthesized by adjusting the number of functional groups and carbon chain length of functional monomers, which can be used for selective recovery of gold(III) from WPCBs leaching solution. The quaternary phosphonium adsorbent (PS-TEP) prepared by the nucleophilic substitution reaction between triethyl phosphine with the smallest volume and chloromethylated polystyrene (PS-Cl) exhibited the best gold loading capacity (617.90 mg g−1). The adsorption mechanism of gold(III) on PS-TEP surface mainly involves anion exchange between AuCl4− and Cl− in the adsorbent. The charge level of the H atom closest to –CH2–P+ group directly determines the strength of the interaction between the adsorbent and the gold ion. Multiwfn and VMD programs visually confirm the weak interaction between PS-TEP+ and AuCl4−. After 5 adsorption-stripping cycles, the adsorption rate of gold(III) in solution remained at about 99 %. In addition, PS-TEP exhibited good gold(III) selectivity in both simulated and actual WPCBs gold leaching solutions. These results indicate that the large-particle PS-TEP with high capacity is suitable for selective gold recovery from WPCBs leaching solution.

Aggregation Behavior and Application Properties of Novel Glycosylamide Quaternary Ammonium Salts in Aqueous Solution.

Amidation of lactobionic acid with N,N-dimethylaminopropyltriamine was conducted to obtain N-(3'-dimethylaminopropyl)-lactamido-3-aminopropane (DDLPD), which was quaternized with bromoalkanes of different carbon chain lengths to synthesize double-stranded lactosylamide quaternary ammonium salt N-[N'[3-(lactosylamide)]propyl-N'-alkyl] propyl-N,N-dimethyl-N-alkylammonium bromide (CnDDLPB, n = 8, 10, 12, 14, 16). The surface activity and the adsorption and aggregation behaviors of the surfactants were investigated via equilibrium surface tension, dynamic light scattering, and cryo-electron microscopy measurements in an aqueous solution. The application properties of the products in terms of wettability, emulsification, foam properties, antistatic, salt resistance, and bacteriostatic properties were tested. CnDDLPB exhibited a low equilibrium surface tension of 27.82 mN/m. With an increase in the carbon chain length, the critical micellar concentration of CnDDLPBD decreased. Cryo-electron microscopy revealed that all products except C8DDLPB formed stable monolayer, multi-layer, and multi-compartmental vesicle structures in an aqueous solution. C14DDLPB has the best emulsification performance on soybean oil, with a time of 16.6 min; C14DDLPB has good wetting and spreading properties on polytetrafluoroethylene (PTFE) when the length of carbon chain is from 8 to 14, and the contact angle can be lowered to 33°~40°; CnDDLPB has low foam, which is typical of low-foaming products; C8DDLPB and C10DDLPB both show good antistatic properties. C8DDLPB and C14DDLPB have good salt resistance, and C12DDLPB has the best antimicrobial property, with the inhibition rate of 99.29% and 95.28% for E. coli and Gluconococcus aureus, respectively, at a concentration of 350 ppm.

Enhancing the sodium-ion storage performance of two-dimensional layered Ti3CN with a molecular riveting strategy

Adjustable 2D layered MXenes hold considerable promising as anode materials for sodium-ion batteries. However, the serious self-stacking and volume variation during sodium-ions insertion/extraction processes inevitably result in inferior rate capability and terrible cycle stability. Herein, we report a novel and effective “molecular riveting” strategy to simultaneously adjust the interlayer spacing and stabilize layered structure of Ti3CN (TCN), which is realized by riveting L-Aspartic acid/L-Glutamic acid/L-2-Aminoadipic acid (LAA/LGA/L2AA, abbreviated as LXA) molecules into interlayers of TCN (named as LAA-TCN/LGA-TCN/L2AA-TCN and abbreviated as LXA-TCN) to form strong amido (HN-C = O) bonds. The riveted LXA molecules between the interlayer of TCN contribute double effects of pillar and strain, achieving the maximum utilization of the 2D layered TCN. As consequences, the interlayer spacing of TCN can be broadened from 1.04 nm to 1.31 nm via altering the carbon chain length of LXA molecules, and the Na+ migration barrier can be reduced from 0.71 eV to 0.08 eV. Meanwhile, the L2AA-TCN with maximum interlayer spacing exhibits a significantly improved reversible capacity of 121.7 mAh/g (45.0 mAh/g for TCN) at 1.0 A/g. The constructed L2AA-TCN//NVP sodium-ion battery (SIB) displays excellent cycle stability with the capacity-retention of 96.6 % after 200 cycles at 10 C. This work opens a new way to broaden interlayer spacing and hinder enormous volume variation of 2D layered MXenes.

Reduction of Fossil Fuel Usage and Emissions of Diesel Engines by the Application of Quaternary Blends and Varied Fuel Injection Pressures.

The increasing energy demand has led to the exhaustion of mineral fuel resources and an environmental menace. Biodiesel and alcohol, as oxygenated fuels, offer promising potential for diesel engines. Moreover, the deviation in the fuel injection pressure (IP) favors improvement of the engine performance and reduction of flue gases. The contemporary research aims to explore sustainable biofuel that is an alternative to diesel and to achieve cleaner emissions with enhanced engine performance. The experiment involves testing of a diesel engine tank by quaternary blends comprising diesel, sunflower biodiesel, sunflower oil, and alcohol in the volumetric ratio of 50:25:5:20. The IP was varied from 300, 400, 500, to 600 bar at different engine loads of 10 and 20 N m at 1800 rpm of shaft speed. The quality of the quaternary blend was varied by the inclusion of alcohol having different carbon-chain lengths, namely, ethanol, propanol, butanol, heptanol, and decanol. The effect of alcohol inclusion and variation in the IP led to minimal brake-specific fuel consumption and maximal brake thermal efficiency for blended fuel containing 20% propanol, which was 17.39% lower and 8.70% higher than diesel, respectively. The same composition of the fuel blend offered the lowest smoke and CO2 emissions, which were 92.85 and 27.9% lesser than diesel; moreover, 7.36% lower NO x emission than diesel was achieved.

Catalytic Upgrading of a Mixed Hydroxy Acid Feedstock Derived from Kraft Black Liquor.

Lignocellulosic feedstocks are widely studied for sustainable liquid fuel and chemical production. The pulp and paper industry generates large amounts of kraft black liquor (BL) from which a high volume of hydroxy acids (HAs) can be separated for further catalytic processing. Here, we explore the catalytic upgrading of HAs, including the conversion of (1) a model HA, gluconic acid; (2) a model mixture of HAs, and (3) a real mixture of HAs derived from kraft BL on M/Nb2O5 (M = Pd, Pt, Rh, and Ru). The hydrodeoxygenation of model gluconic acid reveals that "volatile" carboxylic acids (mainly C2 and C3), levulinic acid, and cyclic esters are significant products over all the catalysts, with Pd/Nb2O5 showing superior activity and selectivity toward valuable intermediates. The model mixture of HAs shows a wide range of reactivity over the supported metal catalyst, with the product selectivity strongly correlating to reaction temperature. Utilizing a 0.25% Pd/Nb2O5 catalyst, a real mixture of HAs derived from kraft BL is successfully dehydroxylated to produce a mixture rich in C3-C8 carboxylic acids that may be amenable for further upgrading, e.g., catalytically to ketones with high carbon chain lengths. Despite the feedstock complexity, we selectively cleaved the C-OH bonds of HAs, while successfully preserving most of the -COOH groups and minimizing C-C and C=O bond scission reactions under the operating conditions tested. The BL-derived HA stream is thus proposed to be a suitable platform for producing mixed carboxylic acid products from an overoxygenated byproduct feed.

Physical properties and diesel engine combustion of blends of alcohols with military jet fuel JP-5

Military operations may involve the use of jet fuel in a diesel engine, and the blending of alcohols with jet fuel is a way to introduce decarbonization into military operations. This study explored the effect of blending n-alcohols with navy jet fuel JP-5 on physical properties and combustion in a diesel engine. Blends containing 10 %, 20 %, and 30 % of ethanol, propanol, butanol, pentanol, hexanol, octanol, and one mixture of 10 % methanol/80 % octanol had densities (0.80 to 0.81 g/mL) that fell within military specifications for diesel. Most mixtures' flash points (16.5 to 65.0 °C) were below the military spec of 60 °C, which is higher than that of commercial aviation fuel. Most mixture viscosities (4.74 to 9.99 mm2/s) were within the jet fuel specifications at −20 °C but below the diesel fuel specification at 40 °C. Combustion of the alcohol/JP-5 mixtures in a diesel engine showed that increasing alcohol content lengthened the ignition delay (IGD). For some of the alcohols, shortening the carbon chain length on the alcohol led to longer IGDs with later combustion phasing that was most noticeable at lighter engine loads. The longer IGDs associated with the shorter alcohol fuels (and increased alcohol percentage) rapidly led to very high rates of energy release. The relative IGDs (IGD mixture/IGD JP-5) were less than 1.2 for the 10 % alcohol mixtures, between 1.0 and 1.4 for the 20 % alcohol mixtures, and between 1.0 and 1.9 for the 30 % alcohol mixtures excluding the 30 % ethanol mixture that did not combust. From the combustion metrics perspective, the longer carbon chain alcohols were most similar to the base jet fuel. Overall, the larger alcohols had physical properties and combustion metrics that were closer to those of the JP-5 jet fuel.

Aging behaviors of asphalt binders rejuvenated by different chemical fractions from waste cooking oil

Waste cooking oil (WCO) can be recycled cleanly as the rejuvenating agent for aged asphalt, boosting the utilization of reclaimed asphalt pavement materials in road engineering. However, the sensitivity of asphalt rejuvenated by WCO to secondary aging is unknown, which has an impact on its durability in practical engineering. The objective of this work is to explore the aging behaviors of asphalt binders rejuvenated by different chemical fractions of WCO. The performance of different fractions of WCO before and after aging treatment was evaluated. The sensitivity to aging was discussed for rejuvenated binders with WCO’s fractions as rejuvenating agents including the differences in aging resistance between them and the virgin binder. The experimental results indicate that the aging resistance of WCO’s fractions depends mainly on their carbon chain length. The sensitivity of rejuvenated asphalt to aging depends strongly on the aging resistance of WCO’s fractions. Additionally, it is found that the resistance of rejuvenated binders to aging is better than that of the virgin binder because the WCO's fractions are less volatile than the original light components of the virgin binder. Therefore, substances with strong fluidity and weak volatility in WCO are the optimal candidates for rejuvenating agents of aged asphalt considering both the rejuvenation effect and the resistance to aging. The findings of the research contribute to the sustainability of road engineering.

Unveiling the dissolution behavior of letrozole in fourteen pure solvents: Insights from experiments and molecular simulations

The dissolution behavior of an active pharmaceutical ingredient (API) in different solvents is of great importance for the design and optimization of its crystallization process. In this study, the solubility of letrozole in fourteen pure solvents was determined using a gravimetric method within the temperature range of 283.15–323.15 K at atmospheric pressure. The results demonstrate a significant correlation between letrozole’s dissolution behavior and the molecular structure (carbon chain length and presence of branched chains) and properties (dielectric constant and cohesive energy density) of the solvent. Solubility analysis and simple crystallization experiments suggest that acetonitrile may serve as a suitable solvent for the cooling crystallization of letrozole. To enhance the applicability of solubility data, five mathematical models were employed for data fitting. In addition, the Van’t Hoff equation was utilized to calculate the apparent thermodynamic properties of the letrozole dissolution process. Furthermore, molecular simulations were conducted to investigate the dissolution behavior of letrozole in different solvents, revealing distinct patterns of interaction between solute and solvent molecules. Specifically, in alcohol solvents, alcohol ether solvents, and acetonitrile, solute molecules interact with solvent molecules primarily as hydrogen bond acceptors, whereas the opposite behavior is observed in ester solvents and acetone. Binding energy, radial distribution function (RDF), and coordination number (CN) analyses effectively elucidate the dissolution behavior of letrozole in solvents of the same category, indicating that stronger solute–solvent interactions result in higher solubility. A comprehensive examination of solute–solvent and solvent–solvent interactions offers a rational explanation for letrozole’s dissolution behavior in solvents of different categories, highlighting the decisive impact of solvent–solvent interactions, particularly in alcohol solvents and acetone.

Efficient separation in n‐butyl ether production process from computational thermodynamics to process intensification

AbstractBiobutanol is a green solvent commonly used as gasoline additive. In this study, it is proposed the separation of azeotropic mixtures of butanol and n‐butyl ether (DBE) using ionic liquids (ILs). Suitable anions [AC]− and [H2PO4]− were screened by COSMO‐RS, and the effect of carbon chain length on the separation effect was investigated using quantum chemical calculations. It was found that the anion was primarily responsible for the separation effect, which grew as the carbon chain grew. Molecular dynamics simulations were used to verify the separation performance of the selected ILs. The separation effect of ILs was further verified using vapor–liquid phase equilibrium (VLE) experiments. The extractive distillation process with [PrMIM][AC] as the extractant was investigated to demonstrate the feasibility of ILs for the separation of butanol and DBE. This study analyzes the whole process from microscopic mechanism of action, which provides new ideas for the separation of alcohol‐ether systems.

Effects of micro- and nano-bubbles on the flotation separation of unburned carbon from coal fly ash

ABSTRACT Nanobubble technology has found extensive use in enhancing the flotation efficiency of various minerals. The utilization of nanobubbles in flotation encompasses bulk nanobubbles, surface nanobubbles, and microbubbles; however, a comprehensive comparison of their respective roles is lacking. Furthermore, there is a dearth of studies on employing nanobubble systems in the flotation of coal fly ash. The coal fly ash characters were initially studied to reveal its ultrafine size (d50: 24.80 μm) and porous structure that includes a multitude of hydrophilic functional groups. These attributes contribute to the inadequate hydrophobicity of unburned carbon within the ash. Subsequently, the effects of different collector types, frother types, and air flow rates on the efficiency of carbon removal using conventional flotation methods were examined. Comparative analysis showed that conventional flotation using diesel oil outperformed that which employed kerosene as the collector. Additionally, higher carbon removal efficiency was achieved using MIBC, with a longer carbon chain length, as the frother, as opposed to sec-Octyl alcohol. Furthermore, a direct relationship between air flow rate and coal fly ash flotation performance was observed – higher air flow rates corresponded to improved flotation outcomes. Finally, a comparison between conventional flotation and nanobubble-assisted flotation (utilizing bulk nanobubbles, surface nanobubbles, and micro-nanobubbles) was conducted. Remarkably, micro-nanobubble flotation yielded the most promising results, with the lowest loss-on-ignition in flotation tailings (3.15%) and the highest removal efficiency of unburned carbon (85.01%). These findings satisfied the loss-on-ignition requirements of Grade I fly ash standards.

Viscosity Reduction Behavior of Carbon Nanotube Viscosity Reducers with Different Molecular Structures at the Oil–Water Interface: Experimental Study and Molecular Dynamics Simulation

Effectively enhancing oil recovery can be achieved by reducing the viscosity of crude oil. Therefore, this paper investigated the viscosity reduction behavior of carbon nanotube viscosity reducers with different molecular structures at the oil–water interface, aiming to guide the synthesis of efficient viscosity reducers based on molecular structure. This study selected carbon nanotubes with different functional groups (NH2-CNT, OH-CNT, and COOH-CNT) for research, and carbon nanotubes with varying carbon chain lengths were synthesized. These were then combined with Tween 80 to form a nanofluid. Scanning electron microscopy analysis revealed an increased dispersibility of carbon nanotubes after introducing carbon chains. Contact angle experiments demonstrated that -COOH exhibited the best hydrophilic effect. The experiments of zeta potential, conductivity, viscosity reduction, and interfacial tension showed that, under the same carbon chain length, the conductivity and viscosity reduction rate sequence for different functional groups was -NH2 < -OH < -COOH. The dispersing and stabilizing ability and interfacial tension reduction sequence for different functional groups was -COOH < -OH < -NH2. With increasing carbon chain length, conductivity and interfacial tension decreased, and the viscosity reduction rate and the dispersing and stabilizing ability increased. Molecular dynamics simulations revealed that, under the same carbon chain length, the diffusion coefficient sequence for different functional groups was -NH2 < -OH < -COOH. The diffusion coefficient gradually decreased as the carbon chain length increased, resulting in better adsorption at the oil–water interface. This study holds significant importance in guiding viscosity reduction in heavy oil to enhance oil recovery.

The aggregation structure and rheological properties of catanionic surfactant mixtures and potential applications in fracturing fluids

Clean fracturing fluids are widely used in reservoir stimulation and increasing production due to their characteristics of simple preparation, no residue, easy flowback, and low damage. At present, clean fracturing fluids are mainly prepared by cationic surfactants as main agent and inorganic or organic salts as additives, which can lead to unavoidable losses of cationic surfactants due to their adsorption in the formation. Anionic-cationic surfactants composite system can not only compensate for the shortcomings of a single surfactant system, but also improve the reservoir adaptability of the surfactant system. In this paper, a clean fracturing fluid was prepared with long-chain anionic surfactant, Sodium erucate (NaOEr), as main agent and a series of cationic surfactants with different as additive. Then, the aggregation behavior of mixed system was determined by visual appearance, rheology experiments, differential scanning calorimetry and cryogenic transmission electron microscopy. The phase transition mechanism induced by temperature was proposed, and the performance of the mixed system as a fracturing fluid was evaluated. The results showed the mixed systems could self-assemble into wormlike micelles when the length of hydrophobic carbon chains of cationic surfactant was 6 and 8. Increasing the length of the hydrophobic carbon chain could enhance the electrostatic effect, leading to precipitation in the mixed system. When the ratio of cationic surfactant was between 0.5 and 0.6 and the concentration was between 68 and 175 mmol∙L-1, the mixed systems tended to form three-dimensional structures by entangling and stacking wormlike micelles, showing high viscoelasticity and viscosity. The aggregation structure of the mixed system transformed from vesicles to wormlike micelles at 46.8 °C, which is attributed to the transition of carbon chains of NaOEr from non-flexible to flexible. Finally, the mixed system as a fracturing fluid has good shear resistance and temperature resistance. The viscosity of NaOEr/HTAB can reach above 50 mPa⋅s after sheared for 60 min at the conditions of 170 s−1 and 80 °C. This study provides an anionic clean fracturing fluid and broaden the application of viscoelastic surfactants in oilfield development.

A novel hepatocyte ketone production assay to help the selection of nutrients for the ketogenic diet treatment of epilepsy

The classic ketogenic diet is an effective treatment option for drug-resistant epilepsy, but its high fat content challenges patient compliance. Optimizing liver ketone production guided by a method comparing substrates for their ketogenic potential may help to reduce the fat content of the diet without loss in ketosis induction. Here, we present a liver cell assay measuring the β-hydroxybutyrate (βHB) yield from fatty acid substrates. Even chain albumin-conjugated fatty acids comprising between 4 and 18 carbon atoms showed a sigmoidal concentration-βHB response curve (CRC) whereas acetate and omega-3 PUFAs produced no CRC. While CRCs were not distinguished by their half-maximal effective concentration (EC50), they differed by maximum response, which related inversely to the carbon chain length and was highest for butyrate. The assay also suitably assessed the βHB yield from fatty acid blends detecting shifts in maximum response from exchanging medium chain fatty acids for long chain fatty acids. The assay further detected a dual role for butyrate and hexanoic acid as ketogenic substrate at high concentration and ketogenic enhancer at low concentration, augmenting the βHB yield from oleic acid and a fatty acid blend. The assay also found propionate to inhibit ketogenesis from oleic acid and a fatty acid blend at low physiological concentration. Although the in vitro assay shows promise as a tool to optimize the ketogenic yield of a fat blend, its predictive value requires human validation.

Performance enhancing of saturated fatty acids with various carbon chain lengths on the structures and properties of zein films in alkaline solvents

Zein, a storage protein rich in hydrophobic amino acids found in maize endosperm, offers significant potential for applications in food packaging. Previous studies on zein films primarily focused on the dissolution of zein in organic solvents. In this study, zein was dissolved in an alkaline solution instead of organic solvents. The effects of fatty acids with varying carbon chain lengths, namely decanoic acid, lauric acid, and palmitic acid, on the structure and properties of zein films were investigated. Alkali-solubilized zein exhibited a various degree of deamidation related to fatty acids after film formation in which decanoic acid significantly reduced the deamidation of zein, while palmitic acid had the opposite effect. Various characterizations confirmed that fatty acids were evenly distributed within the film matrix, disrupting the intermolecular interactions of zein and preventing zein molecules from aggregation; this eventually led to a tightly structured film. The addition of fatty acids, specifically decanoic acid and lauric acid, significantly enhanced the performance of the zein films. After loading decanoic acid or lauric acid, the almost opaque zein films had a visible light transmittance of over 50% while maintaining an excellent UV light blocking property. The tensile strength and elongation at break of the films were improved, and their water vapor permeability was reduced by an order of magnitude. This study provides insights into zein plasticization and paves the way for developing organic solvent-free food packaging.

Preparation and characterization of hydrophobic waterborne polyurethane self‐matting coating

AbstractA green method to synthesize self‐matting waterborne polyurethane acrylic hybrid emulsion with hydrophobic function is introduced in this study. A reactive waterborne polyurethane (RWPU) dispersion containing unsaturated CC double bonds was prepared from epoxidized soybean oil. Subsequently, the RWPU dispersion was copolymerized with fluorinated monomers of different carbon chain lengths to prepare polyurethane acrylic hybrid emulsion (PUF). The results revealed the gloss levels of PUF films to be as low as 12.4 gloss units at 60°. The morphology of PUF films was observed by scanning electron microscope and three‐dimensional surface profilometer, and the relationship between surface roughness and gloss was discussed in detail. In addition, thermal gravimetric analysis was conducted to determine the thermal stability of the PUF films, and the results denoted that these PUF films exhibited excellent thermal stability. Comprehensive performance tests indicated that the RWPU dispersion, which was copolymerized with hexafluorobutyl methacrylate at a weight of 10%, exhibited a low gloss, a high contact angle of 120°, and a high elongation percentage of 423%. Furthermore, the dynamic light scattering results showed small average particle size, revealing the excellent storage stabilities.