Nonpolar Components Research Articles

Enhanced energy storage in antiferroelectrics via antipolar frustration.

Dielectric-based energy storage capacitors characterized with fast charging and discharging speed and reliability1-4 play a vital role in cutting-edge electrical and electronic equipment. In pursuit of capacitor miniaturization and integration, dielectrics must offer high energy density and efficiency5. Antiferroelectrics with antiparallel dipole configurations have been of significant interest for high-performance energy storage due to their negligible remanent polarization and high maximum polarization in the field-induced ferroelectric state6-8. However, the low antiferroelectric-ferroelectric phase-transition field and accompanying large hysteresis loss deteriorate energy density and reliability. Here, guided by phase-field simulations, we propose a new strategy to frustrate antipolar ordering in antiferroelectrics by incorporating non-polar or polar components. Our experiments demonstrate that this approach effectively tunes the antiferroelectric-ferroelectric phase-transition fields and simultaneously reduces hysteresis loss. In PbZrO3-based films, we hence realized a record high energy density among all antiferroelectrics of 189 J cm-3 along with a high efficiency of 81% at an electric field of 5.51 MV cm-1, which rivals the most state-of-the-art energy storage dielectrics9-12. Atomic-scale characterization by scanning transmission electron microscopy directly revealed that the dispersed non-polar regions frustrate the long-range antipolar ordering, which contributes to the improved performance. This strategy presents new opportunities to manipulate polarization profiles and enhance energy storage performances in antiferroelectrics.

Sliding ferroelectricity influenced by charge doping in bilayer antiferromagnetic H–ScO2

Sliding ferroelectricity has been extensively studied as it provides an approach to designing van der Waals ferroelectric materials with nonpolar components. In this work, we demonstrate the sliding ferroelectricity of bilayer H–ScO2, which is formed by an interlayer antiferromagnetic configuration of monolayer H–ScO2 ferromagnetic material. The out-of-plane polarization results from charge transfer between the layers, causing an unequal charge distribution within them and yielding a polarization value of ±1.26 pC/m. We found that increasing the doping concentration suppresses the polarization value. This phenomenon results from the differing occupancy ratios of electrons and holes in the conduction and valence bands after introducing electron or hole doping into the system. The closer the number of electrons in the conduction band is to that in the valence band, the more pronounced the suppression of polarization. Our work offers a perspective for the design of advanced van der Waals ferroelectric materials.

Evaluation of the antiulcer activity of ethanolic extract and solvent fractions of Calendula tripterocarpa Rupr. in experimental rats and their DART-ToF-MS profiling

In this study, antiulcer activity of ethanolic extract and solvent fractions of the aerial part of Calendula tripterocarpa was investigated using ethanol-induced model of gastric ulceration in rats. The results showed that ethyl acetate, non-polar components and diethyl ether fractions have a remarkable antiulcerogenic activity; because they exhibited control-ulcer protection by 85.2%, 77.7% and 62.9%, respectively. The acute toxicity study showed that the extract is highly safe; the median lethal dose (LD50) was more than 5000 mg/kg. Moreover, the obtained results were confirmed by the sub-chronic toxicity and showed no alteration in the liver and kidney functions. Our data suggests that C. tripterocarpa possesses significant antiulcer activity and it can be used as a source for an antiulcer drug. Around 100 compounds are elucidated from this plant using direct analysis in real-time of flight-mass spectrometry for the first time, of which four well-known compounds were not isolated or reported previously.

Supercritical fluid extraction and encapsulation of Rivas (Rheum ribes) flower: Principal component analysis (PCA).

Supercritical CO2 modified by polar solvents can extract a wide variety of polar and non-polar chemical components compared to conventional methods. The current study aims to extract Rivas (Rheum ribes) flower using the ethanol modified supercritical CO2 (SCO2-EOH) method; analyze its chemical compounds and bioactivity, encapsulate the extract in maltodextrin, gum-Arabic (GA), and their combination (GA+MD) using the spray drying method and investigate the differences among microparticles using Principal Component Analysis (PCA). The Rivas extract obtained by the SCO2-EOH method was a rich source of unsaturated fatty acids (mainly linoleic acid: 57.58%), phytosterols (mainly sitosterol: 197.02 and campesterol: 144.47mg/100g), terpenoids (mainly camphor: 17.52%; and 1,8-cineol: 10.91%) and phenolics (mainly m-coumaric acid: 48.22; luteolin: 38.07 and gallic acid: 26.25mg/g). The yield of Rivas extract was 1.62±0.27%. The extract bioactivity was as follows: antioxidant activity of 89.6±1.39%; total phenolic content of 306.19±13.59mg GAE/g; total flavonoid content of179.84±5.77mg QE/g and a comparable antimicrobial effect to synthetic antimicrobials against E. coli, L. monocytogenes, and A. fumigatus. The encapsulation efficiency of microparticles was 90.53% for MD to 93.23% for GA+MD (P<0.05). The microparticles had irregular semi-spherical shapes with wrinkled surfaces. According to the PCA, MD showed the best solubility and the lowest price, making it a cost-effective ingredient to improve the nutritional-value of food formulations. If the stability of bioactive compounds is more important, GA+MD will be the best choice.

Dyeing of synthetic fiber-based wool blended fabrics in supercritical carbon dioxide

AbstractDevelopment of supercritical carbon dioxide (SC-CO2) dyeing technology for natural fabrics and their blended fabrics is essential for the textile industry due to environmental and economic considerations. Wool (W), polyester (PET) and nylon (N) fabrics and their wool/polyester (W/PET) and wool/nylon (W/N) blended fabrics were dyed in SC-CO2 medium with a synthesized reactive disperse dye containing a vinylsulphone (VS) reactive group, which behaves as a disperse dye for synthetic fibers and a reactive dye for protein fibers. The SC-CO2 dyeing performance of all fabrics was investigated in terms of color strength, fixation, colorimetric and fastness measurements and compared with the conventional aqueous dyeing method. The results obtained indicate that the VS reactive disperse dye structure and non-polar PET component mainly improved colour strength (K/S) values of the dyed PET fabric and W/PET blended fabrics in SC-CO2 compared with those in the aqueous medium. Also, SC-CO2 dyeing has a notable influence on a*, b* and C* values of the dyed PET, N and W/PET fabrics and showed that the uptake of the VS reactive disperse dye and their appearance colors are higher and more saturated than the aqueous dyed samples. The levelling and fastness properties of all dyed fabrics in SC-CO2 medium are similar to those obtained in the aqueous medium. It was observed that VS reactive disperse dye penetrates well into the PET fabric and is chemically bound with the W fabric using both SC-CO2 and aqueous media and did not display significant color difference (∆E) values of W, PET and W/PET fabrics even after 20 washing cycles. The study claims that the VS reactive disperse dye structure and dyed PET-based wool blended fabric are good candidates for industrially SC-CO2 dyeing technology.

Quasi-hydrophobic deep eutectic solvents for simultaneous automated determination of polar and non-polar dyes in food products

In this work, quasi-hydrophobic deep eutectic solvents were used for the first time for the efficient extraction of both polar (Sunset Yellow FCF (E 110), Azorubine (E122), Ponceau 4R (E124)) and non-polar (Sudan I, Sudan II, Sudan III) dyes from food products at the same time. These solvents were made from polar and nonpolar components, which made it possible to extract analytes of various natures. To automate the technique, a flow analysis method was used, which increases the speed and reliability of determining analytes in food samples. For a detailed study of extraction mechanisms, various process modeling methods were used. The proposed DES-based method addresses the limitations of traditional extraction methods, offering a more robust and efficient solution for food analysis. Validation of the method has demonstrated high precision, accuracy and extraction efficiency, making it a promising tool for regulatory compliance and consumer safety in the food industry. The following analytical characteristics were achieved: the limits of detection were 0.03–0.13 mg L−1, limits of quantification were 0.09–0.44 mg L−1, an extraction recovery exceeding 85 %, a linear range was from 1 to 100 mg L−1, and a relative standard deviation ranging from 2 % to 10 %. The experiments were confirmed by both Conductor Like Screening Model-Segment Activity Coefficient (COSMO-SAC) and the Non-Covalent Interaction using the Reduced Density Gradient of the DES-dye system in aqueous media.

Development of Wood-Based functional composites for advanced sensing and energy conversion applications

With the low carbon-driven development of modern intelligent, research towards novel materials is concentrating on the sustainable biomass-based advanced functional composites. The advanced functionalized wood toward sensing, optoelectronic devices, and energy conversion has been contributed to fast electron transport upon temperature or photo stimulus. Fast electron transport has been highly depended on the interfacial adhesion between the functional layer and wood matrix as well as graphitization degree during carbonization, which promote the electronic excitation and jumps. Here, we develop wood-based functional composites for advanced fire warning and energy conversion by loading metal–insulator transition (MIT) function factor (Ti3O5) onto different woods via liquid crosslinkers, and systematically establish the interfacial adhesion-carbonization-electron transport processes and their relationships on the sensing and photothermal conversion properties. Firstly, balsa with high porosity (pore diameter ≈50 μm), low density (0.16 g/cm3) and extractives content (total extractives content 16.27 %) facilitates crosslinker penetration due to the more holding space and lower nonpolar components. A favorable permeation can promote better interfacial adhesion, and the formation of a continuous conductive network of char-layers during carbonization. Secondly, the crosslinker (chitosan) with excellent adhesion (1 level) and char-forming ability (char residues is 21.7 %), facilitates the formation of a compact network of highly graphitized char-layers (ID/IG=0.81), which increases the electrical conductivity (highest conductivity 5.52 × 10-4 S/m). We found that the most sensitive flame trigger time (0.86 s) for fire warning and the highest evaporation flux (1.63 kg m-2h−1) for desalination can be obtained by using balsa which coupled the chitosan as well as the Ti3O5.

Free radical fragmentation and oxidation in the polar part of lysophospholipids: Results of the study of blood serum of healthy donors and patients with acute surgical pathology

The interaction of reactive oxygen species with cell membrane lipids is usually considered in the context of lipid peroxidation in the nonpolar component of the membrane. In this work, for the first time, data were obtained indicating that damage to human cell membranes can occur in the polar part of lysophospholipids at the interface with the aqueous environment due to free radical fragmentation (FRF) processes. FRF products, namely 1-hexadecanoyloxyacetone (PAc) and 1-octadecanoyloxyacetone (SAc), were identified in human serum, and a GC-MS method was developed to quantify PAc and SAc.The content of FRF products in serum samples of 52 healthy donors was found to be in the range of 1.98–4.75 μmol/L. A linear regression equation, CPAc&SAc (μmol/L) = 0.51 + 0.064 × years, was derived to describe the relationship between age and content of FRF products. In 70 patients with acute surgical pathology in comparison with the control group of healthy donors, two distinct clusters with different concentration levels of FRF products were revealed. The first cluster: groups of 43 patients with various localized inflammatory-destructive lesions of hollow organ walls and bacterial translocation (septic inflammation) of abdominal cavity organs. These patients showed a 1.5–1.9-fold (p = 0.012) decrease in the total concentration of PAc and SAc in serum. In the second cluster: groups of 27 patients with ischemia-reperfusion tissue damage (aseptic inflammation), – a statistically significant increase in the concentration of FRF products was observed: in 2.2–4.0 times (p = 0.0001).The obtained data allow us to further understand the role of free-radical processes in the damage of lipid molecules. FRF products can potentially be used as markers of the degree of free-radical damage of hydroxyl containing phospholipids.

A novel environmentally-friendly filler of the asphalt mastic: Organic modified waste shells

The shell farming industry generates significant waste shells annually, often improperly disposed of, causing environmental pollution. Concurrently, pavement engineering faces a shortage of limestone resources. Utilizing waste shells as a substitute for limestone fillers could simultaneously address both environmental and resource challenges. To analyze the feasibility of this strategy, this work collected the mussel, pectinid, oncomelania and oyster as the raw materials, and the method of organic modification was adopted on these shells to enhance the compatibility between the filler and asphalt. Asphalt. The physical and rheological properties of the prepared asphalt mastics were evaluated, and the modification effect was determined by the contact angle test and the surface energy parameters. Results indicated that the asphalt mastics with modified shells had higher penetration and ductility while lower softening point compared to the mastics with unmodified shells. Moreover, the modification with aluminate coupling agent had more significant impact on the physical properties of the asphalt mastics than that using amino silicone oil. For the rheological properties, shell asphalt mastics exhibited an extremely complex rheological behavior due to the various polarity and the organic content of the shell fillers. Besides, the contact angle of the shells increased after the modification, implying a better compatibility with asphalt. Moreover, the results of the surface energy parameters indicated that the non-polar component of the shells increased obvious after modification. In comparison with the conventional limestone, it can be found that the modified shells enhanced the adhesion between the aggregates and the asphalt mastics, which can improve the resistance of asphalt mixture to water damage. This work verifies the feasibility to replace the conventional mineral filler with modified shell filler, which was beneficial to recycling the waste shell and reducing the consumption of non-renewable mineral resources.

Critical role of vacancy defects in graphene nanosheets for enhancing asphalt binder

Clarifying the interaction between the intrinsic structure of graphene and asphalt binder is critical to achieve the practical application of graphene modified asphalt. Herein, the thermal-mechanical properties and thermal-oxidative aging resistance of asphalts modified by two types of exfoliated graphene (EG) with less vacancy and vacancy-defected graphene (VDG) were investigated via multi-scale methods, aiming at elucidating the role of vacancy defects in graphene. Rheological measurements demonstrate that VDG have stronger capability of improving the deformation resistance and aging resistance of asphalt than EG. Atomic force microscopy analysis further verifies that VDG has a strong interaction with the non-polar components of asphalt, forming dense micellar structures. In addition, molecular dynamics simulations evidence that the vacancy defects in graphene can form the electrostatic adsorption between asphalt hydrocarbon molecules (light components), increasing the concentration and densification of asphaltenes, promoting the transformation of asphalt from sol structure to gel structure, thereby significantly improving the thermal-mechanical and anti-aging properties of asphalt binder. And the interaction is also verified by infrared spectral analysis and gaussian calculation through peak displacement. The discovery of the effect of vacancy defects in graphene for reinforced asphalt deepens the understanding for developing high performance graphene modified asphalts.

Chemical Composition of Larch Oleoresin before and during Thermal Modification

Larch is a strong timber, which grows rapidly in the UK climate, but can contain abundant resin pockets. To address the resin exudation issue, a mild thermal modification process has been developed, promoting the curing of the resin. This paper reports a series of studies which characterised the chemical profile of larch oleoresin before and after the mild thermal treatment, explaining the changes which occur when resin is dried. Further experiments were used to simulate specific points in time during the mild treatment process. The non-polar components of the fresh (untreated) and treated larch oleoresin were profiled using gas chromatography mass spectrometry (GC-MS). Fresh larch oleoresin was also subjected to isothermal experiments at different temperatures in a thermogravimetric analyser–differential scanning calorimeter (TGA/DSC), followed by re-analysing the resin composition. This demonstrated the loss of monoterpenes at temperatures of 120 °C and above, with complete loss by isothermal conditions of 150 °C and 60 min. The partial loss of sesquiterpene alkanes and alkenes were also observed at all temperatures, although completeness of this loss was achieved at isothermal temperatures of 150 °C and above. The diterpene composition was seen to change for isothermal experiments conducted at 150 °C and above, with a dehydration of terpenols to form the equivalent terpene alkenes. The observed physical changes in the TGA/DSC experiment were in good agreement with observations of the oleoresin sampled from thermally modified larch planks.

Improvement of augmented free-water flash algorithm based on HV mixing rule and simulated annealing optimization algorithm

The calculation of three-phase equilibrium in CO2-hydrocarbon-water mixtures holds significant importance within numerical simulations, particularly in applications such as CO2-enhanced oil recovery and carbon dioxide sequestration. However, due to the non-ideality of CO2 and the polarity of water, three-phase equilibrium calculations often encounter convergence challenges. The augmented free-water flash algorithm [6], specifically focusing on CO2 dissolution in the aqueous phase, addresses the convergence challenges encountered by traditional three-phase flash algorithms. Despite its accuracy diminishes under conditions of high pressure and high CO2 concentrations, limiting its capability to accurately describe CO2 dissolution in oil-gas-water multiphase systems. The GE (excess Gibbs free energy) type mixing rule can be effectively integrated with equations of state, including PR and SRK, by utilizing activity models like NRTL and UNIFAC, which can be applied to the calculation of thermodynamic parameters for both nonpolar and polar systems and high-pressure complex systems. In this study, based on the augmented free-water assumption, we have developed a new augmented free-water three-phase flash algorithm for CO2/hydrocarbon/water mixtures. This algorithm integrates the PR equation of state with the NRTL activity model, employing the HV mixing rule for CO2-water interactions and the Van der Waals rule for other non-polar components. Furthermore, to enhance computational efficiency, the algorithm incorporates the simulated annealing global optimization algorithm, replacing Newton iteration to more effectively identify the global minima of the complex objective function. The example calculations show that the improved augmented free-water flash algorithm has higher accuracy and efficiency than the traditional augmented free-water flash algorithm. The augmented free-water three-phase flash algorithm proposed in this paper offers a precise model for phase equilibrium calculations essential for numerical simulations in CO2-enhanced oil recovery and carbon dioxide sequestration.

DETERMINATION OF CHAMAZULENE BY REVERSED PHASE HPLC

A method for the determination of hamazulene in essential oils using reverse-phase high-performance liquid chromatography with diode-matrix detection has been developed. The possibility of qualitative determination of hamazulene from the electronic absorption spectra recorded in the detector cell and quantitative determination of this substance during detection at several different wavelengths is shown. To obtain chromatograms, it is proposed to use C18 stationary phase with a mobile phase containing 20 vol. % water in acetonitrile. Samples for the study were prepared by dissolving essential oils in acetonitrile. The chromatographic determination of hamazulene is not hindered by the accompanying components of the studied essential oils of four plants: Matricaria chamomilla, Achillea millefolium, Tanacetum annuum and Artemisia absinthium; the concentration of hamazulene in them was 0.184, 0.311, 0.299 and 0.0025 mol/l, respectively. The wavelength of 603 nm provides the most selective detection of hamazulene along a complex electron-vibrational band for a solution in the mobile phase. When the detection wavelength changes from 603 to 350 and up to 280 nm, the sensitivity of hamazulene detection increases by 15.5 and 187 times. The chromatographic method has a linear response of the detector despite the known features of the electronic absorption spectra of azulene derivatives. It was found that when a blue-colored spot of hamazulene is isolated from TLC plates, other nonpolar components of oils that are detected when recording a chromatogram under HPLC conditions at a detector wavelength of 210 nm also enter the extract. It was also found that when recording chromatograms at 200 nm, differentiation of oils is possible, since most of the components of these oils have at least one isolated double C=C bond in the structure, which allows detecting compounds at 190-200 nm. For citation: Deineka V.I., Salasina Ya.Yu. Determination of chamazulene by reversed phase HPLC. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 6. P. 6-20. DOI: 10.6060/ivkkt.20246706.6989.

Superhydrophilic and oleophobic sponges prepared based on Mussel-Inspired chemistry for efficient oil-water separation.

Superhydrophilic/oleophobic materials are considered to be the best materials for achieving oil-water separation, but their preparation is difficult and the existing methods are not universal. In this paper, a two-step modification strategy was used to prepare superhydrophilic/oleophobic sponges by adjusting the polar and nonpolar components of the materials using mussel-inspired chemistry. While remaining superhydrophilic, the modified sponge surface has a maximum contact angle of 135° with different oils in air. The modified sponge exhibited superoleophobicity in water, and the contact angle of oil could reach more than 150°. In addition, the modified sponges were also reusable, chemically stable, and mechanically durable. Its oil-water separation flux was up to 24900 Lm-2 h-1 bar-1 , and the separation efficiency was above 97 %. We believe that this method will provide an environmentally friendly and efficient way to prepare the superhydrophilic/oleophobic materials.

Analysis of wave breaking on synthetic aperture radar at C-band during tropical cyclones

ABSTRACT The purpose of our work is to analyze the effect of wave breaking on dual-polarized (vertical-vertical (VV) and vertical-horizontal (VH)) synthetic aperture radar (SAR) image in the C-band during tropical cyclones (TCs) based on the machine learning method. In this study, more than 1300 Sentinel-1 (S-1) interferometric-wide (IW) and extra wide (EW) mode SAR images are collocated with wave simulations from the WAVEWATCH-III (WW3) model during 400 TCs. The validation of the significant wave height (SWH) simulated using the WW3 model against Jason-2 altimeter data. The winds for S-1 SAR images are reconstructed using wind retrievals in VV and VH polarization. The non-polarized (NP) contribution σ wb caused by wave breaking is assumed to be the result of the SAR-measured normalized radar cross-section (NRCS) σ 0 minus the Bragg resonant roughness σ br without the distortion of rain cells during TCs. The σ br is simulated by imputing wave spectra from the WW3 model into the theoretical backscattering model. It is found that the ratio (σ wb /σ 0) in VV polarization is related to the wind speed, the wind direction relative with the flight orientation, and radar incidence angle. Following this rationale, the Adaptive Boosting (AdaBoost) model was used for the estimation of NP contribution σ wb during TCs and are implemented for more than 300 dual-polarized S-1 images to validate the model. It is found that for the comparison between the sum of simulation NRCS and SAR observations, the root mean squared error (RMSE) is 1.95 dB and the coefficient (COR) is 0.86, which is better than a 2.83 dB RMSE and a 0.67 COR by empirical model. It is concluded that the AdaBoost model has a good performance on NP component simulation during TCs.

Phytotoxic and Cytotoxic Effects, Antioxidant Potentials, and Phytochemical Constituents of Stevia rebaudiana Leaves.

Stevia (Stevia rebaudiana), recognized for its low-calorie, sugar-free attributes, and various health benefits, has potential applications beyond human consumption, particularly in agriculture. This study explored the potential uses of Stevia in both agricultural and healthcare contexts by examining its plant-inhibitory, cytotoxic, and antioxidant effects. The methanolic extract of Stevia leaves was fractionated into hexane, ethyl acetate, chloroform, and water fractions. These fractions were then subjected to the bioassay analyses above and underwent identification of their chemical constituents. The results indicated that the ethyl acetate fraction demonstrated significant inhibitory effects on weed germination and growth of Beggars tick (Bidens frondosa) (100% inhibition at 1000 ppm of dose). This fraction also exhibited the highest antioxidant activity, total phenolic, and total flavonoid contents (IC50 DPPH = 18.67 μg/mL, 103.50 mg GAE/g fraction, and 410.16 mg QE/g fraction, respectively). In contrast, the chloroform fraction showed the highest cytotoxic effect (LC50 = 700.01 ppm) in the brine shrimp (Artemia salina) mortality evaluation. Pearson's correlation analysis revealed a positive correlation among plant inhibitory effects, antioxidant potentials, and phenolic/flavonoid contents of Stevia. FTIR spectra confirmed the presence of phenols and nonpolar components in the ethyl acetate and chloroform fractions. In addition, GC-MS analysis successfully identified Stevia's key constituents, including tetracontane, hexadecane, hexadecanoic acid, methyl ester in the ethyl acetate fraction, and spiro [4.5] decan-7-one and 6-hydroxy-4,4,7a-trimethyl-5,6,7,7a-tetrahydrobenzofuran-2(4H)-one in the chloroform fraction. This study underscores the potential of S. rebaudiana as a source of natural antioxidants and herbicides, offering valuable insights into its diverse applications in agriculture.

Efficient catalyst regeneration through solvent-based wax extraction for Co/Al2O3 Fischer-Tropsch catalysts

The regeneration of Fischer-Tropsch (FT) catalysts plays a crucial role in sustaining their catalytic activity and longevity in sustainable production processes. This research investigates the effectiveness of various solvents, including n-hexane, n-heptane, toluene, xylene, and the liquid fraction of FT products (LF-FT), for catalyst regeneration and extracting wax from the 15 wt%Co/Al2O3 catalyst. Toluene, with a unique combination of key parameters such as polarity, solubility, boiling point, aromatic structure, and chemical interactions, exhibited the highest wax removal efficiency of 90.6%. However, due to its 41 °C lower boiling point compared to toluene and very similar wax removal efficiency, n-hexane appears as a more energy-efficient and cost-effective option for this process. The regenerated catalysts showed comparable characteristics, including the textural properties (surface area, pore size, and pore volume), crystallinity, and reducibility, to fresh catalysts. The slightly lower reduction temperature in the regenerated catalyst indicates a higher possibility for the formation of cobalt active sites during the catalyst reduction process with hydrogen, leading to an increased potential for higher catalytic activity. The LF-FT, comprising paraffins, iso-paraffins, olefins, napthenes, and aromatics, provided a unique combination of aliphatic and aromatic moieties, enhancing the solubility of both polar and nonpolar components in FT wax and improving the wax removal efficiency to 91.5%. The higher boiling point and operating temperature of the LF-FT also contributed to its better performance. Efficient separation of hydrocarbons from solvents allowed for solvent reusability in subsequent FT wax removal cycles, making it advantageous for large-scale applications.

Promotional effect of shaped coal gangue composite phase change agents doping in asphalt on pavement properties

To address issues related to the limited improvement in the performance of phase-change material (PCMs) modified asphalt and the unclear underlying mechanisms, this study developed two structurally stable and thermally efficient coal gangue composite phase-change agents. The impact on enhancing the properties of asphalt was systematically investigated. The study revealed that when the dosage of the phase-change agent is below 20%, there was a pronounced interactive effect between the agent and asphalt. This interaction had the capability to regulate both the non-polar and polar components within the asphalt colloid system. By controlling the dosage of the PCMs agent, it was possible to enhance the high-temperature rheological properties, high-temperature shear resistance and low-temperature flexibility of the asphalt. Additionally, this control improved the adhesion and moisture sensitivity of the PCMs modified asphalt and aggregate system. The maximum temperature-regulating effect of PCMs modified asphalt could reach up to 8.3 °C, with the functional attribute strongly correlated with the low-temperature performance of the asphalt. This research contributes to the promotion and application of PCMs in road engineering.

Effects of cosolvents on CO2 displacement of shale oil and carbon storage

Molecular dynamics method was used to establish composite wall/inorganic nanopores of three pore sizes, three shale oil systems, five CO2-cosolvent systems, and pure CO2 system. The process of CO2-cosolvent displacement of crude oil in shale nanopores and carbon storage was simulated and the influencing factors of displacement and storage were analyzed. It is shown that the attraction of the quartz wall to shale oil increases with the degree of hydroxylation. The higher the degree of quartz hydroxylation, the more difficult it is to extract the polar components of shale oil. Nanopore size also has a great impact on shale oil displacement efficiency. The larger the pore size, the higher the shale oil displacement efficiency. The closer the cosolvent molecules are to the polarity of the shale oil, the higher the mutual solubility of CO2 and shale oil. The more the non-polar components of shale oil, the lower the mutual solubility of CO2 and shale oil with highly polar cosolvent. Ethyl acetate is more effective in stripping relatively high polar shale oil, while dimethyl ether is more effective in stripping relatively low polar shale oil. Kerogen is highly adsorptive, especially to CO2. The CO2 inside the kerogen is not easy to diffuse and leak, thus allowing for a stable carbon storage. The highest CO2 storage rate is observed when dimethyl ether is used as a cosolvent, and the best storage stability is observed when ethyl acetate is used as a cosolvent.

Alkyl ketene dimer modification of thermomechanical pulp promotes processability with polypropylene

AbstractAlkyl ketene dimers (AKDs) are known to efficiently react with cellulose with a dual polarity in their structure: a polar component and a nonpolar component. AKD of three different carbon chain lengths, 4, 10, and 16 carbons have been synthesized, and thermomechanical pulp (TMP) fibers were modified by them. The modification of TMP fibers with AKD resulted in an increased water contact angle, showing the presence of the AKDs on the TMP fibers and a new carbonyl peak in the IR spectra, suggesting modification of the TMP fibers with AKD groups. Calculating the Hansen solubility parameters of AKD and AKD conjugated to TMP in polypropylene (PP) indicates improved compatibility, especially of longer chain AKD and TMP AKD. The rheological studies of the composites showed that the AKD with the longest carbon chain decreases the melt viscosity of the PP‐TMP‐AKD composite, which combined with the shape and the color of the extruded composite filaments indicates improved flow properties and reduced stress build up during processing. The research findings demonstrate the ability of AKD to enhance the dispersibility and compatibility of natural fibers with PP.