Search Results (204)

Oleogels have emerged as promising alternatives to conventional solid fats by structuring liquid oils without increasing trans or saturated fat levels. This study therefore aimed to develop rice bran oil (RBO)-based oleogels using beeswax (BW), carnauba wax (CW), and their combinations, and to compare their physicochemical properties with commercial margarine. Thirteen formulations with varying wax concentrations were prepared and analyzed using differential scanning calorimetry, microscopy, rheology, texture profile analysis, oil binding capacity, slip melting point, peroxide value, color analysis, and fatty acid profiling. Our results demonstrated that the thermal behavior of the oleogels is dependent on the type and concentration of the wax, with CW oleogels exhibiting higher crystallization and melting temperatures than BW, while hybrid systems displayed intermediate and synergistic properties. Distinct crystal morphologies were observed, with BW forming needle-like and CW forming spherulitic structures, while the hybrids created interconnected networks. All samples exhibited shear-thinning and gel-like behavior, with greater viscosity and gel strength observed at increasing wax concentrations. The hybrid oleogels achieved hardness comparable to higher CW levels and approached margarine texture, while maintaining high oil binding capacity (>94%). The RBO oleogels contained higher unsaturated fatty acids but showed lower oxidative stability than margarine. Overall, BW–CW hybrid oleogels demonstrated strong potential as healthier, solid fat alternatives with improved structural and thermal characteristics. Full article

Aiming at the characteristics of high viscosity and poor fluidity of high waxy ordinary heavy oil, a Janus silica-based nanosheet composite viscosity reducer was designed and prepared in this paper. The viscosity reducer was assembled by asymmetric Gemini viscosity reducer and silica nanosheets through dehydration condensation reaction, and its structure was verified by FT-IR, ¹HNMR, XPS and DLS. The viscosity reduction performance, emulsion stability, interfacial tension and flow performance of the viscosity reducer were systematically evaluated by taking heavy oil with wax content of 35.7% and viscosity of 237 mPa·s at 30 °C as the research object. The results showed that, at an oil-to-viscosity-reducer-solution volume ratio of 3:7 and a viscosity reducer mass fraction of 0.3%, the maximum viscosity reduction rate reached 94.5% at 30 °C, calculated relative to the viscosity of the dehydrated original heavy oil. The oil–water interfacial tension was significantly reduced, and the 24 h bleeding ratio, defined as the volume percentage of separated water relative to the initial aqueous phase volume, was only 7.3%, indicating good emulsion stability. The core flow experiment shows that the resistance coefficient is reduced to the lowest at 0.3% concentration, and the seepage capacity is significantly improved. The analysis of total hydrocarbon gas chromatography showed that the content of high-carbon wax components in the C₂₃-C₃₀ range decreased by 4.79 percentage points after treatment, indicating that the viscosity reducer preferentially interacted with high-carbon wax molecules and promoted wax-crystal dispersion, thereby weakening the three-dimensional wax-crystal network. The viscosity reducer has the synergistic effect of dispersing wax crystals, reducing interfacial tension and stabilizing emulsification, which provides a low-cost and high-performance technical approach for the efficient exploitation of high waxy ordinary heavy oil. Full article

Heavy oil production and transportation are often restricted by high viscosity, poor mobility, and unfavorable low-temperature flow behavior, especially in waxy systems. While conventional polymer-based additives improve flow, they suffer from inadequate thermal stability, poor dispersibility in complex crude oil matrices, and insufficient multifunctionality. To address these issues, a nano-SiO₂-based organic-inorganic hybrid flow improver, denoted as NSDA, was synthesized via in situ free-radical copolymerization of styrene, docosyl methacrylate, acrylic acid, and acrylamide on 3-(trimethoxysilyl)propyl methacrylate (KH-570)-modified silica surfaces. Characterization revealed that this core-shell nanohybrid structure significantly improved thermal stability and oil-phase dispersibility, maintaining nanoscale dispersion in xylene. A remarkable viscosity reduction rate of 90.2% was achieved, accompanied by a substantial pour point depression of 11 °C using only 0.5 wt% of NSDA in Liaohe heavy oil. This dual-functional performance is mainly attributed to the combined effects of the robust nano-SiO₂ core and the multifunctional polymer shell, Specifically, the performance is driven by synergistic wax crystal regulation at low temperatures, alongside weakened intermolecular associations among polar heavy components and nanoparticle-assisted dispersion that govern viscosity reduction. Full article

The non-isothermal crystallization behavior of CF/PEEK composites during the cooling stage of processing significantly influences their final properties. However, the effect of PEEK melt fluidity on the crystallization kinetics and crystal morphology of CF/PEEK composites under varying cooling rates remains to be elucidated. This study employed differential scanning calorimetry (DSC) combined with crystallization kinetic models including Avrami and Mo equations to analyze the non-isothermal crystallization process, while wide-angle X-ray scattering (WAXS) characterized the crystal morphology. The results indicate that with increasing PEEK melt fluidity, the crystallinity of CF/PEEK composites rose from 22.2% to 25.93% at a cooling rate of 5 °C/min, accompanied by an enhanced crystallization rate. Mechanical testing revealed that the mechanical properties improved with increasing fluidity: the tensile and flexural strengths increased from 264.8 MPa and 413.3 MPa for CF/PEEK20 to 299.1 MPa and 476.5 MPa for CF/PEEK146, respectively. Furthermore, as the PEEK melt fluidity increased, the dominant factor governing crystallization behavior shifted from chain structural stability to molecular chain mobility, and ultimately to nucleation capability. Full article

Biodegradable materials offer promising alternatives to petroleum-based polymers. This study investigates poly(ε-caprolactone) (PCL) and poly(lactic acid) (PLA) nanocomposites reinforced with 1, 3 and 5 wt.% cellulose nanocrystals (CNCs) extracted from sugarcane bagasse via melt blending. The thermal, structural, morphological and biodegradation properties were evaluated using differential scanning calorimetry (DSC), scanning electron microscopy (SEM), X-ray scattering (WAXS/SAXS), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and biodegradation tests. SEM results revealed uniform dispersion of CNCs at low concentrations, whereas agglomeration occurred at higher concentrations for both PCL and PLA. At 1 wt.% CNCs, there was minimal impact on the biodegradation rates of both polymers, despite achieving uniform dispersion. However, significant acceleration in biodegradation was observed at 5 wt.% CNCs, attributed to the enhanced hydrophilic nature of the nanocomposites. CNCs acted as nucleating agents in PCL crystallization, while reducing the crystallization rate of PLA. This led to a mass loss of 36.4% for PCL and 82.2% for PLA, correlating with increased and decreased crystallinities, respectively. The study concludes that the hydrophilic–hydrophobic balance has a more significant influence on biodegradation rates than crystallinity or CNC dispersion. Full article

This study presents a risk assessment of asphaltene–resin–paraffin deposition (ARPD) in the producing formations of the XIII reservoir unit of the Uzen oil field at a late stage of development. The crude oil is characterized by an extremely high paraffin (wax) content of up to 29 wt.%. Long-term operation of the reservoir pressure maintenance (RPM) system with cold water injection has resulted in significant reservoir cooling, with temperatures declining from the initial 60–65 °C to 20–30 °C in zones of intensive waterflooding. To refine the critical phase transition temperatures of paraffin components, a dynamic laboratory approach was applied using a Wax Flow Loop system, which simulates wax deposition processes under flowing conditions. The results indicate that the wax appearance temperature (WAT) ranges from 41.0 to 44.0 °C, significantly exceeding the current bottomhole temperatures in the cooled zones of the reservoir. Intensive bulk crystallization of paraffins occurs within the temperature interval of 33.5–35.0 °C, while loss of oil flowability is observed at 25–34 °C, corresponding to the gelation and structural network formation of wax crystals under reduced thermal conditions. The obtained results confirm the inevitability of bulk oil structuring and solid wax phase precipitation directly within the reservoir porous medium. This process leads to blockage of low-permeability interlayers, deterioration of filtration properties, and a reduction in the displacement efficiency factor by 20–35%. Under the current thermal regime, ARPD should therefore be considered not merely as an operational flow assurance issue, but as a systemic factor limiting reservoir development efficiency. The research results substantiate the need to transition from reactive ARPD removal methods to proactive management of the thermal regime of the reservoir and wells, as well as to the differentiated application of thermal and chemical treatment methods. Full article

Wax deposition occurs to varying degrees in most oil and gas wells. The basic data of existing wax precipitation prediction models are mainly single-component wax experimental data based on the melting process of wax crystals during heating, which is quite different from the cooling crystallization process of wax in oil and gas production. Moreover, the published solubility test data of binary n-alkanes are mainly concentrated in the range of nC10–nC36, leaving existing thermodynamic models without available data for predicting the behavior of high-carbon alkanes. Based on the idea of wax crystallization and precipitation during cooling, this study experimentally determined the solid–liquid equilibrium solubilities of high-carbon n-alkanes (nC38, nC40, nC44, nC48 and nC50) with different concentrations in n-heptane, n-nonane and n-dodecane, as well as the crystallization parameters of pure substances, by using a DSC instrument. This effectively fills the gap in the basic physical property data of long-chain alkanes (more than nC36) and the cooling process in existing studies. In addition, we measured the crystallization parameters of pure high-carbon n-alkanes (nC38, nC40, nC44, nC48 and nC50) during cooling, including crystallization temperature, transition temperature, crystallization enthalpy and transition enthalpy under cooling conditions. The experimental data are in good agreement with the solubility predicted by the ideal solution model for the cooling process, with an average absolute percentage error of less than 10% and average solubility deviation generally within 0.078 mol%. This indicates that the ideal solution model has good accuracy for predicting the precipitation of n-alkane wax and n-alkane solvents. This study provides basic data for the prediction theory of paraffin precipitation. Full article

Developing potential skincare formulations capable of simultaneously managing infection and promoting tissue repair remains a critical challenge in dermatological care. This study engineered bioactive oleogels using sunflower wax (SFW), rice bran wax (RBW), and 12-hydroxystearic acid (HSA) to deliver a synergistic essential oil blend (ginger, cinnamon, tea tree, geranium). A D-optimal mixture design optimized formulations to match the textural profile of a commercial benchmark. Crucially, the fatty acid architecture of the carrier oil emerged as a primary determinant of network integrity; the high oleic acid content in camellia oil facilitated robust RBW crystallization by minimizing steric hindrance, whereas the polyunsaturated, kinked structure of linoleic acid in almond oil disrupted SFW networks, resulting in lower stiffness. Thermal characterization (DSC) established a distinct stability hierarchy with RBW exhibiting the highest melting point (Tp = 60.1 °C) and enthalpy (ΔHm = 7.79 ± 0.74 J/g). Thermogravimetric analysis (TGA) confirmed high thermal resistance for wax-based systems (Tdeg ≈ 357 °C), whereas HSA displayed a biphasic degradation starting at ~206 °C. FTIR spectroscopy verified the stable physical entrapment of bioactives, with the lipid vehicle dominating the spectral fingerprint. Rheological profiling revealed that RBW oleogels, structured in high-oleic camellia oil, formed rigid networks (G′ ≈ 5.7 × 104 Pa) with high yield stress (20.91 Pa), offering superior retention. In contrast, HSA oleogels displayed “smart” thixotropic recovery with lower stiffness (G′ ≈ 2.1 × 104 Pa) and a distinct melting peak at 22.5 °C, compared to 60.1 °C for RBW. All formulations achieved a >2 Log₁₀ reduction (99%) in Staphylococcus aureus and Pseudomonas aeruginosa viability after 12 h. Furthermore, in vitro keratinocyte assays identified a hormetic therapeutic window at 1–5 μg/mL (essential oil blend equivalent); specifically, SFW oleogels at 5 μg/mL stimulated proliferation to 158.07% relative to controls. These findings confirm that optimizing the lipid vehicle–bioactive interface creates dual-action scaffolds capable of simultaneously managing infection and stimulating in vitro keratinocyte proliferation. Full article

This study is devoted to a comparative analysis of modern methods for determining the wax crystallization onset temperature (WCOT) of high-paraffin crude oil from the Uzen field. The objects of investigation were crude oil samples from the 13th reservoir horizon with a paraffin mass content ranging from 22.5% to 27.5%. For the first time in the practice of the oil and gas industry of Kazakhstan, a comprehensive comparison of results obtained using two fundamentally different approaches was performed: the light transmittance method using the KING-UNNP-70 apparatus, which simulates reservoir conditions (pressure of 12 MPa), and a dynamic method using a Wax Flow Loop facility, which reproduces crude oil flow in a pipeline. The experimental results showed that the light transmittance method detects the appearance of the first microcrystals at temperatures of 38.0–41.7 °C, whereas the dynamic method yields higher WCOT values, ranging from 41.0 °C to 44.0 °C. It was also found that the temperature of bulk crystallization, characterizing intensive solid phase formation, lies within the range of 33.5–35.0 °C. The results confirm that under flow conditions, paraffin crystallization begins at higher temperatures compared to static conditions, which is of critical importance for the design of crude oil gathering and transportation systems. The obtained data allow more accurate prediction of the risks of asphaltene–resin–paraffin deposits (ARPD) formation and optimization of technological operating conditions of wells at the late stage of field development. Full article

The plant cuticle is a hydrophobic layer covering the cell wall that protects cells from pathogen invasion and water loss. In this study, we analyzed the cuticles of transgenic Arabidopsis thaliana plants overexpressing the vesicular trafficking small GTPase RabA2b. The RabA2b-overexpressing plants exhibited distinctive structural and chemical modifications in their cuticles, including enhanced hair-like wax crystals and increased accumulation of phenolic compounds such as ferulic acid and coumaric acid, which contribute to cutin cross-linking and reinforcement of the cuticle matrix. These chemical and structural changes were associated with improved barrier function and increased drought resistance. Our findings suggest the involvement of RabA2b in affecting the plant cell’s exterior by altering the cuticle composition and architecture, thereby improving plant tolerance to water deficit. Full article

Phase change materials (PCMs) have emerged as an innovative solution in thermal energy storage and thermal management systems (TMS) owing to their outstanding latent heat of fusion during the phase change process. This study is especially addressed to the battery TMS based on Organic PCMs for fast charging/discharging applications of lithium-ion batteries (LIBs). These fast processes generate excessive heat during operation, degrade battery performance, decrease energy efficiency, and reduce the lifespan and safety of batteries. Organic PCMs exhibit desirable properties, including high latent heat capacity, good thermal characteristics, low cost, and ease of integration. The major challenge for the successful application of organic PCM comprises its low thermal conductivity, which impacts the heat storage and release rates. PCM-based Paraffin Wax (PW) has been designed by including expanded graphite (EG) as a high thermal conductivity additive in high latent heat of paraffin wax. Experiments focused on the effects of heating methods (microwaves/S-type EG composition and conventional electric oven/S′-type EG composition) of expandable graphite on the thermophysical properties of different PW/EG composites. The crystal and chemical structure of the study samples were analyzed by X-ray diffraction and Fourier-Transform Infrared spectroscopy. The battery module created with PW/EG composites were ample examined using charging/discharging experiments at five different C-rates. The effect of current rates on battery surface temperature is investigated in two cases: with PCM cooling and with air cooling. A 20.43% decrease in battery temperature is found at 5C rate with PCM cooling and a maximum reduction in battery charging time of 43.77%. Full article

This study investigates the effects of high-pressure compression molding on the molecular orientation and mechanical properties of biomass-derived aliphatic polyamide (PA11). Tensile fracture strength exhibited a significant increase—up to 2.4 times that of untreated samples—under conditions of 1000 kN and 140 °C. Differential Scanning Calorimetry (DSC) and Wide-Angle X-ray Scattering (WAXS) analyses revealed a temperature- and pressure-dependent shift in crystalline phases, suggesting a transition from α’ to phase. The δ’ phase, formed by high-pressure compression molding, is retained even after cooling to room temperature (i.e., Brill transition was not observed). In addition, polarized optical microscopy (POM) observations further supported the presence of changes in molecular orientation. This enhancement (under conditions of 1000 kN and 140 °C) is primarily attributed to the molecular orientation. However, it is also noteworthy that the formation of the δ’ phase is accompanied by an increase in the degree of crystallinity, and that this δ’ phase is retained even after cooling to room temperature without undergoing a Brill transition. In contrast, at 180 °C, although the degree of crystallinity increased, molecular orientation decreased, resulting in reduced tensile strength. These findings indicate that the mechanical properties of PA11 are governed by a complex interplay among phase transitions, molecular orientation, and crystallization, all of which are strongly influenced by temperature and pressure conditions. These findings demonstrate that high-pressure compression molding is an effective method for enhancing the mechanical properties of PA11 through controlled phase transition and orientation Full article

As a vital appearance quality trait of broccoli, curd-surface wax powder not only affects its commercial value but also plays a key role in plant resistance to abiotic stresses. However, its formation mechanism remains unclear. Using low-wax variety CK (‘QH18’) and high-wax variety T1 (‘QHMS4’) as materials, this study systematically elucidated the molecular mechanism of wax powder formation via physiological indexes, scanning electron microscopy (SEM), targeted metabolomics, and transcriptomics. Determination of fatty acid (FA) content in broccoli flower bud tissue showed a close association between FA content and wax deposition. SEM observation revealed that T1 had significantly denser wax crystals, mainly granular, than CK. Targeted metabolomics identified 25 fatty acids in the two varieties. And the linolenic and palmitic acids, with high content and significant differences, may be key metabolites regulating wax synthesis. Integrated transcriptomics and metabolomics indicated that BolfabG, BolLACS, BolKCS1, BolKCS2 and BolMAH1 genes are involved in wax biosynthesis. Moreover, AP2/ERF-ERF transcription factor (TF)-encoding genes (BolERF018, BolERF1F.1, BolERF1F.2 and BolERF1C) played the primary role in regulating wax biosynthesis, followed by NAC (BolNAC62.1), MYB (BolMYB44), and MADS-MIKC(BolPISTILLATA). These TFs may regulate BolfabG, BolLACS, BolKCS1, BolACOX2 and BolACAA1 to affect linolenic and palmitic acid balance, altering wax precursor synthesis and accumulation, and finally leading to differences in wax morphology and content. This study reveals a “Transcription Factors–Differentially Expressed Genes–Differentially Accumulated Metabolites–Fatty Acids” (TFs-DEGs-DAMs-FA) network, providing a basis for understanding broccoli wax formation. Full article

Glossy appearance is a critical trait that affects the appearance quality and marketability of leafy vegetables, including Chinese cabbage. The glossy trait is primarily associated with cuticular wax. Although several genes involved in cuticular wax biosynthesis have been characterized in Chinese cabbage, the regulatory relationships among them remain unclear. In this study, we identified a glossy mutant, glossy leaf4 (gl4), and cuticular wax crystals in the gl4 mutant were obviously reduced. Genetic analysis indicated that the glossy phenotype in the gl4 mutant appears to be controlled by a single recessive gene. Using a bulked segregant analysis coupled with next-generation sequencing (BSA-seq) and map-based cloning methods, the AtCER2 homologous gene BrCER2 was identified as the candidate gene. BrCER2 was expressed in various tissues, and BrCER2-GFP was localized in the endoplasmic reticulum (ER). Furthermore, BrCER2 could interact with BrKCS6 in the ER, and the expression levels of some wax biosynthesis-related genes were decreased in the gl4 mutant. Our overall results provide insights about the role of BrCER2 in wax biosynthesis through ER localization and interaction with BrKCS6 in Chinese cabbage. Full article

Cuticular wax plays an important role in the quality of kumquat (Fortunella crassifolia Swingle) fruit. In this study, the wax morphology, compositional profile of epi- and intracuticular wax, and crucial gene expression in ‘Rongan’ kumquat (RAK) and ‘Huapi’ kumquat (HPK) were analyzed during fruit development. The results showed that the surfaces of two kumquat fruits were covered with an amorphous wax layer containing a small number of platelets. Compared to RAK, HPK contained more abundant and larger wax crystals during fruit development. In two kumquat fruits, the epicuticular wax and its major compositions consistently displayed significantly higher levels than the intracuticular wax. Additionally, their main wax composition shifted from alkanes in the early developmental stages to triterpenoids at harvest in both layers, while aldehydes were specifically enriched in the epicuticular wax. During the fruit development from 90 to 180 DAF, HPK fruit exhibited significantly higher levels of epicuticular wax and its majority fractions than RAK fruit. Meanwhile, the intracuticular wax contents of HPK from 90 DAF to 150 DAF were significantly higher than those in RAK, with triterpenoids accounting for the largest proportion of this increase. qRT-PCR results indicated that the up-regulation of wax-related genes in HPK was linked to its increased epicuticular wax deposition during the development. Overall, this study provided a comprehensive overview of the morphology, composition, and biosynthesis of cuticular wax in kumquat fruit during development. Full article