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A facile method for synthesising porous carbon materials with high nitrogen content is employed in this study using 1H-Benzotriazole (BTA) as carbon precursor and ZnCl as active agent at 600-800 °C for 2 h under N atmosphere. Pure BTA completely degrades even at low temperature (270 °C) under inert gas, but ZnCl can convert the more organics to carbon because of its dehydration. The obtained NC-2-700 sample possesses a high specific surface area (1228 m·g) and a nitrogen content up to 10.27 wt%. Moreover, the N-doped carbon exhibits a good electrochemical property (with a specific capacitance of 332 F·g at the current density of 0.5 A·g), as well as an outstanding cycle stability (96.5% of the initial specific capacitance is maintained after 5000 cycles at 1 A·g). In addition, this obtained symmetric ultra-capacitor prepared from the NC-2-700 sample exhibits a highest energy density of 12.94 Wh·kg with a power density of 375 W·kg at a current density of 1 A·g. And even this NC-2-700//NC-2-700 supercapacitor gives 5.43 Wh·kg with a power density of 3750 W·kg at a high current density of 10 A·g. Consequently, these experimental results confirm that the porous carbon materials with high nitrogen content can be a prospective electrode material for supercapacitors. [ABSTRACT FROM AUTHOR]

Nitrogen-containing porous carbons with numerous micropores were fabricated by pyrolysing polyvinylidene fluoride (PVDF) membrane following potassium hydroxide (KOH) activation at 600-900 °C for 2 h under N atmosphere. The fabricated nitrogen-containing porous carbons have a large specific surface area of approximately 2289 m g, a certain nitrogen content of 1.35 at.% and a favourable hierarchical porous structure possessing a great number of micropores and a part of mesopores. The carbon materials exhibit high specific capacitance of 338 F g at 0.5 A g in a 6 M KOH and outstanding cycling property of 91.6% maintenance at 2 A g after 10000 cycles. An all-solid-state symmetrical supercapacitor with these as-prepared materials as electrodes can deliver energy densities of 21.9 to 10.4 W h kg at power densities from 700.8 to 12910.3 W kg. To sum up, the as-obtained porous carbon is a type of potential electrode material for electrical double-layer capacitor. [ABSTRACT FROM AUTHOR]

Poly( m-phenylenediamine)-coated hexagonal CoS was firstly synthesized by the polymerization with self-prepared hexagonal Co(OH) used as cobalt source, and the calcination with sulfur powder providing sulfur source. By adjusting the concentration of m-phenylenediamine in the polymerization process, the coating was achieved with the different coated results, further affecting their supercapacitor behaviors by improving diffusion path for fast electron transfer. The resulting CoS/PmPD electrodes demonstrate excellent electrochemical performance with high specific capacitance of 950.1 F g at a current density of 0.5 Å g, good rate performance of 81.1% capacitance retention as the current density grows from 0.5 to 20 Å g, and almost no capacitance loss after 1000 cycles. Moreover, as asymmetric positive electrode material, the CoS/PmPD-1 shows high specific capacitance of 115.3 F g at 0.5 Å g, outstanding rate performance of 78.2% capacitance retention even increased to 20 Å g, superior cycle stability of 87.9% capacitance retention after 5000 cycles at 2 Å g and largest energy density of 36.0 W h kg at power density of 374.67 W kg. This novel CoS/PmPD composite suggests a bright prospect for supercapacitor applications. [ABSTRACT FROM AUTHOR]

Ultrasound-assisted biodiesel production is an emerging technology that features high energy density, high conversion efficiency, and environment friendliness. This review evaluates the influence of process parameters, including ultrasonic power, ultrasonic frequency, catalyst dosage, alcohol/oil ratio, reaction temperature, reaction time, and alcohol type, on the yield of ultrasonic-assisted production of biodiesel. Limitations associated with ultrasonic-assisted production of biodiesel are also analyzed. Further development of this technology is explored. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The first example of a heterogeneous iron(III)-catalyzed aerobic oxidation of aldehydes in water was developed. This method utilizes 1 atmosphere of oxygen as the sole oxidant, proceeds under extremely mild aqueous conditions, and covers a wide range of various functionalized aldehydes. Chromatography is generally not necessary for product purification. Its operational simplicity, gram-scale oxidation, and the ability to successively reuse the catalyst, make this new methodology environmentally benign and cost effective. The generality of this methodology gives it the potential to be used on an industrial scale. [ABSTRACT FROM AUTHOR]

Waste cooking oil biodiesel (BWCO) was used to investigate the influences of polymethyl acrylate (PMA) pour point depressant mixed with common dispersants on the cold flow property of biodiesel. Results showed that PMA mixed with Span80 dispersant at a mass ratio of 2:1 exhibited the best synergistic effect on reducing the cold filter plugging point (CFPP) by 7°C with respect to pure biodiesel. Performance mechanisms were also explored and showed that mixed improvers have better dissolution and dispersion in biodiesel, effectively inhibited the formation of larger crystals, and reduced the amount and sizes of crystals, thereby improving the cold flow properties of biodiesel. [ABSTRACT FROM PUBLISHER]

This investigation was conducted to determine the cold flow properties of waste cooking oil biodiesel with methyl acetoacetate (MAA) as a potential flow improver. Now, 0.0 vol%, 2.5 vol%, 5.0 vol%, 7.5 vol%, 10 vol%, 15 vol%, and 20 vol% MAA were added to study the effects on the cold flow properties of waste cooking oil biodiesel. The results indicated that the filter plugging point, pour point (PP), and cold point (CP) were decreased by 5°C, 5°C, and 7°C, respectively, after being treated with 20 vol% MAA. Other fuel properties were also determined and compared with ASTM D6571. Additionally, the performance mechanism was explored by differential scanning calorimetry and polarizing microscopy. [ABSTRACT FROM PUBLISHER]

Heteroatom doped porous carbons have shown great potential as metal-free catalysts for electrochemical catalyzed oxygen reduction reaction (ORR). Most previous works have been focused on preparation of single and dual heteroatom doped porous carbons for ORR. In this work, we developed a new two-step method for preparation of boron, nitrogen, and phosphorus (B, N, P) ternary doped hierarchically porous graphene aerogels by using boron phosphate as both B and P precursor and ammonia as N dopant. As-produced ternary-doped graphene aerogels exhibited promising ORR performance (mainly 4e− mechanism, Jk: −4.6 mA cm−2) in alkaline medium in comparison with commercially available precious metal based Pt/C catalyst. As-prepared B/N/P ternary doped hierarchically porous graphene aerogels can serve as the next generation of metal-free catalysts and alternatives to precious metal catalysts for oxygen reduction reaction and fuel cells. [ABSTRACT FROM AUTHOR]

• N-containing polymers were synthesized as PPDs for diesel. • C 14 MC-AM (9:1) combined with EVA-2 showed a better depression effect. • PPDC-5 in diesel exhibted the highest ΔSP (28 °C) and ΔCFPP (23 °C). The combined-pour point depressants (PPDs) have shown potential for the improvement of the cold flow properties of diesel. In this study, free radical polymerization was used to polymerize methacrylate (RMC) and acrylamide (AM) in different molar ratios (1:1, 3:1, 6:1, 9:1, 12:1, 15:1). Methacrylate-acrylamide copolymers (RMC-AM) were synthesized and analyzed through Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H NMR), and thermogravimetric analysis (TGA) to characterize the copolymers. Through exploring the effect of different chain lengths and different monomer molar ratios on the solid point (SP) and cold filter-plugging point (CFPP) of diesel, C 14 MC-AM (9:1) showed relatively good performance (ΔSP = 25 °C, ΔCFPP = 10 °C). Then, ethylene–vinyl acetate copolymer (EVA) materials with different VA content were introduced in this study. Diesel treated with 1000 ppm of EVA-2 (VA = 28%) showed relatively good performance (ΔSP = 18 °C, ΔCFPP = 10 °C). C 14 MC-AM (9:1) was mixed with EVA −2 in different ratios (1:0, 4:1, 2:1, 1:1, 1:2, 1:4, and 0:1, namely, PPDC-1 ~ 7) to produce synergy and improve the cold flow properties of diesel. The ΔSP and ΔCFPP of diesel fuel treated with only 500 ppm PPDC-5 can reach 28 °C and 23 °C, respectively. In addition, the crystallization behavior and crystal morphology of the treated diesel fuel were discussed through differential scanning calorimeter, polarized optical microscope and rheological analysis. The results showed that the combined-PPD made the wax crystals dissolve in the diesel system. The wax crystals became more uniform and denser under the action of AM polar groups. [ABSTRACT FROM AUTHOR]

• Inertinite-rich in raw coal were further separated into two different densities via density flotation. • There is a progressive difference in different components of inertinite. • Quantum chemical calculation can be used to evaluate the reactivity of coal. Inertinite content is a main factor affecting oil yield. In this study, raw coal with high inertinite content was selected to investigate the chemical structural characteristics of inertinite of different densities. Inertinite-rich (>1.30 kg/L) in raw coal was further separated into low (LDI, 1.30–1.38 kg/L)- and high (HDI, >1.38 kg/L)-density samples via density flotation. Structural models of raw coal, LDI, and HDI were built on the basis of the analytical results obtained from solid-state 13C nuclear magnetic resonance, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The characterization data and molecular structural models showed no significant difference in the aromaticity of raw coal, LDI, and HDI, and the types and quantities of structural units in all samples were nearly identical. Bond length and bond order data obtained by using quantum chemical calculation were simultaneously combined with the molecular structural models, and raw coal, LDI, and HDI demonstrated progressive differences in number of active breaks of chemical bonds and fragment structures after bond breakage. [ABSTRACT FROM AUTHOR]

In this work, hemicellulose-derived porous activated carbon materials are synthesized by a new method. The nanoporous carbon is prepared for the first time by one-step chemical activation of hemicellulose. The hemicellulose extracted from pomelo peel is used as precursor, and zinc chloride is used as the activator. The porous activated carbon material with large specific surface area of up to 1361 m2 g−1 is fabricated by a one-step chemical activation at a low temperature of 500 °C. The roles of the activator/carbon material ratio and activation temperature are studied in detail. Benefiting from the porous structure and favorable activation temperature, the as-prepared carbon material possesses ideal electrochemical capacity. The porous activated carbon material performs an excellent specific capacitance of 302.4 F g−1 at the current density of 0.5 A g−1 in 6 M KOH and cycling stability of 98.6% capacitance retention after 10000 cycles. For all-solid symmetric supercapacitor, the energy density is 11.7 W h kg−1 at the power density of 349.9 W kg−1. The hemicellulose-derived porous activated carbon material shows unique properties, making it an ideal advanced electrode material for high-performance supercapacitors. Fig. 1. The graphical abstract of HPAC-x-y materials. Image 1 • The carbon source of the material is hemicellulose. • Porous carbon is synthesized by a one step ZnCl 2 activation. • Porous carbon is prepared at low temperature of 500 °C. • The raw material of the activated carbon is pomelo peel. • The HPAC-1-500 sample exhibits large surface area of 1361 m2 g−1 and 98.6% capacitance retention. [ABSTRACT FROM AUTHOR]

To meet the requirements of a circular economy, a class of sulfur- and phosphorus-free green bifunctional lubricating oil additives was developed based on corn cob extract as a naturally renewable biomass material. These additives can significantly enhance the friction-reducing, anti-wear properties, and oxidative stability of base oils. Results indicate that at an addition level of 4000 ppm, ternary polymer additive reduced the wear volume and surface roughness of steel friction pairs by 98.17 % and 97.63 %, respectively, and increased the oxidation induction period by 40.52 %. The improvement in tribological performance is attributed to the rigid ring structure preventing direct contact between friction pairs, and the chemical adsorption of carboxylic acid and anhydride groups with the metal, forming a dense friction film. [ABSTRACT FROM AUTHOR]

[Display omitted] • By extracting citric acid from waste cotton leaves, the biomass waste can be reused and the production cost is low and biodegradable. • A claw-shaped polymer lubricant additive with citric acid as the core skeleton was designed (PTV-nT, n=1,5,10). • The tribological regularity of claw type polymer additives at different concentrations and polymerization degrees were investigated. • The tribological mechanisms of claw type polymer additives with PAO10 as the base oil were discussed. Renewable energy has garnered extensive attention owing to its environmentally friendly and sustainable characteristics. In this context, the present study, for the first time, extracted natural citric acid from agricultural waste (cotton leaves) and developed a series of sulphur- and phosphorus-free claw-shaped polymeric lubricant additives (PTV-nT, where n = 1, 5 and 10). These eco-friendly polymeric additives demonstrated a significant enhancement in the anti-friction and anti-wear performance of the PAO10. The tribological properties of the polymeric additives were systematically evaluated using a four-ball tribometer, white-light interferometry, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The mechanism of action was further explored, and the structure-performance relationship between the claw-shaped polymer structure and its tribological properties was investigated. At an additive concentration of 4000 ppm, the PTV-1T additive reduced the average friction coefficient and wear volume of steel friction pairs by 29.6 % and 95.6 %, respectively. The superior tribological performance of the lubricants is primarily attributed to the polymer additives, which accelerated the formation of adsorption films and tribo-chemical films on the frictional surfaces. Additionally, the use of polymer additives reduced the oil viscosity, significantly mitigating adhesive wear and abrasive wear. [ABSTRACT FROM AUTHOR]

The MoS 2 /AlOOH nanocomposites were prepared through a facile one-pot hydrothermal method and subsequently employed as lubricating oil additives to improve the tribological properties of PAO4 base oil. The structure, composition, morphology, tribological properties, and lubrication mechanism of the MoS 2 /AlOOH nanocomposites have been investigated. The results demonstrated that the in-situ assembly of MoS 2 on the surface of AlOOH change their microstructure, resulting in enhanced dispersion and a reduction in friction and wear. At 0.5 wt% concentrations of MoS 2 /AlOOH nanocomposites, the average COF, WSD, and wear volume were decreased by 50.47 %, 42.34 %, and 86.57 % compared to base oil, respectively. Moreover, the tribological behaviors of the PAO4 containing MoS 2 /AlOOH nanocomposites under various conditions were explored as well. Furthermore, based on the analysis of micromorphology and composition of wear surfaces, a synergistic lubrication mechanism for MoS 2 /AlOOH nanocomposites has been proposed, which involves the formation of a tribochemical film composed of Fe 2 O 3 , Fe 3 O 4 , MoS 2 , and Al 2 O 3 and demonstrates remarkable capabilities in reducing friction and wear. This research might provide new insight into enhancing the tribological properties of MoS 2 -based additives through the composite method and promote the application of MoS 2 /AlOOH nanocomposites as additives. • MoS 2 /AlOOH nanosheets were successfully synthesized using a facile one-pot hydrothermal method. • The in-situ assembly of MoS 2 on the AlOOH derived from superfine Al 2 O 3 had altered their respective electronic structures. • Wider interlayer spacing (MoS 2) and weaker hydrogen bonding energy (AlOOH) were formed in the MoS 2 /AlOOH nanosheets. • MoS 2 /AlOOH nanosheets had superior tribological properties and dispersibility in lubricants. [ABSTRACT FROM AUTHOR]

The poor cold flow properties (CFPs) are the main factors that hinder the utilization and popularization of diesel fuel. Cold flow improvers (CFIs) are usually add to diesel fuel to compensate for liquidity problems at low temperatures. In this study, monomers with different functional groups were used to synthesize methyl benzyl acrylate-co-hexadecene-maleic anhydride (MB-HD-MA) terpolymers with different mole ratios through free radical polymerization, and then the terpolymers were modified with tetradecanol to obtain comb type terpolymers (MB-HD-MA-C14). The structure of MB-HD-MA and MB-HD-MA-C14 were characterized by Fourier transform infrared spectroscopy (FTIR) and Nuclear Magnetic Resonance Hydrogen spectra (1 H NMR). Adding CFIs to diesel fuel effectively improved the CFPs, 1000 ppm MB-HD-MA-C14 (3:1:4) presented the best depression effects on cold filter plugging point (CFPP) and solid point (SP) by 12 °C and 21 °C, respectively. The results showed that the non-polar and polar components in CFIs exert synergistic effect at an optimal ratio to improve CFPs with greater efficiency. Moreover, rheology analysis and polarizing optical microscopy showed that MB-HD-MA-C14 (3:1:4) can improve the rheological properties by reducing dynamic viscosity and improve the crystallization behavior of wax crystals at low temperature by decreasing the size and modifying the morphology of the wax crystals. [Display omitted] • A series of comb type terpolymers of methyl benzyl acrylate-co-hexadecene-maleic anhydride with tetradecyl pendant (MB-HD-MA-C14) were synthesized as cold flow improvers (CFIs). • MB-HD-MA-C14 (3:1:4) at 1000 ppm presented the best depression effects on cold filter plugging point (CFPP) and solid point (SP) by 12 °C and 21 °C, respectively. • Rheology analysis and polarizing optical microscopy showed that MB-HD-MA-C14 (3:1:4) can improve the rheological properties by reducing dynamic viscosity and improve the crystallization behavior of wax crystals at low temperature by decreasing the size and modifying the morphology of the wax crystals. [ABSTRACT FROM AUTHOR]

Although water-soluble redox based supercapacitors (SCs) had attractive supercapacitor characteristics, they still suffered from problems of low operating voltages and unsatisfactory energy density. Herein, it was reported that the oxygen defect modulated copper oxide on flexible carbon fiber (denoted as CuO x /CF) achieved a broad potential range of up to 3.0 V in 1 M Na 2 SO 4 contained 0.05 M K 4 [Fe (CN) 6 ]/K 3 [Fe (CN) 6 ] electrolyte. Oxygen defects in CuO x /CF improved charge transfer efficiency, adjust [Fe (CN) 6 ]3−/4− ions diffusion and stimulated more pseudocapacitive behavior, which demonstrated by electrochemical characterization and theoretical calculation results. It is noteworthy that the 3.0 V high voltage water-soluble CuO x /CF based symmetric supercapacitor yielded a maximum energy density of 53.1 Wh kg−1 at a power density of 1950 W kg−1 and exceptionally remarkable cycling durability of 98.9%. This work presented a viable strategy for constructing wide-voltage flexible supercapacitor devices. [Display omitted] • Introduced defect engineering successfully increased specific capacitance of CuO x /CF symmetric supercapacitor. • The water-soluble redox electrolytes broaden the voltage window and improved ionic conductivity. • DFT theoretical calculation analysis was performed for the contribution of oxygen vacancies modulated copper oxide for the energy storage. [ABSTRACT FROM AUTHOR]

The applications and development of biodiesel fuels are restricted by the poor low-temperature fluidity and oxidation stability. Meanwhile, typical antioxidants are usually compounds containing phenyl groups, which have the disadvantages of high toxicity and carcinogenicity. To address these defects, our study originally synthesized a multifunctional additive using both post grafting and nanocomposite technology, as well as apply a biofuel antioxidant free of benzene ring group, 4-Amino-2,2,6,6-tetramethylpiperidine. Our findings reveal that the delayed crystallization behavior of B20 (20 vol%. biodiesel +80 vol%. diesel) is strongly dependent on the additive structure and amount, which the pour point (PP) and cold filter plugging point (CFPP) are decreased by 20 and 16 °C respectively at 1000 ppm. The post grafting technology enhanced additive antioxidant properties, which extend the induction period of B20 from 2.0 to 6.9 h. Our study confirmed the synthesized additives through possess synergistic enhancement effects on both cold flow properties and oxidation stability. In addition, DFT calculations simulating the potential energy changes of B20 solutions forecast copolymer structure affects the low-temperature fluidity. Hence this study pioneered the proposal for developing multifunctional additives through both post grafting and nanocomposite technology of methacrylate copolymer for biofuels, and provide a theoretical prediction strategy for exploring optimum copolymer pour point depressant for fuels. [Display omitted] • A novel copolymer nanocomposite was prepared as a multifunctional additive for fuels. • The oxidation induction time of treated B20 is increased from 2.0 to 6.9 h. • The pour point and cold filter plugging point are decreased by 20 and 16 °C, respectively. • DFT calculations reveal the copolymer structure affected the cold flow properties. • The nanocomposite additives exhibit synergistic enhancement on the drawbacks of B20. [ABSTRACT FROM AUTHOR]

[Display omitted] • Type-II NH 2 -MIL(FeCo)/TO composite photoanode was successfully prepared for PEC water oxidation. • The optimized hetero-interface dramatically enhanced separation-transfer of the charge carriers. • Octahedral NH 2 -MIL(FeCo) provided abundant bimetallic active sites for boosting the STH conversion. • Photocurrent density and STH efficiency of the target sample were 5.08 and 5.26 times of pristine system. Employing TiO 2 photoanode toward photoelectrochemical (PEC) water splitting has emerged as a tremendously prospective route of exploiting solar energy with considerable appeal. However, owing to severe electron-hole recombination phenomenon and relative lack of charge transfer capability, its application is somewhat limited. In this study, we presented in-situ growth of photosensitive amine-functionalized FeCo metal–organic frameworks (NH 2 -MIL(FeCo)) on surface of TiO 2 nanorods (TO) employing hydrothermal approach for significantly boosting PEC water oxidation. NH 2 -MIL(FeCo) and TO constructed hetero-interfaces successfully mitigated interfacial recombination barriers and promoted more effective charge transfer. Simultaneously, octahedral NH 2 -MIL(FeCo) endowed composite photoanode abundant bimetallic active sites, accelerating reaction kinetics and thus facilitating charge transfer effectively. Additionally, NH 2 -MIL(FeCo) coating not only served as a protective layer for TO, but also enhanced the stability of TO. Consequently, NH 2 -MIL(FeCo)/TO demonstrated an impressive photocurrent density of 2.44 mA cm−2 at 1.23 V vs reversible hydrogen electrode. Charge injection and separation efficiencies were dramatically improved to 91.06 % and 94.12 %, respectively. After a 5 h long-term stability, current retention remained at 91.96 %. Herein, this study revealed that NH 2 -MIL(FeCo) provided a potential pathway to construct a high-efficiency photoanode for stable PEC water oxidation. [ABSTRACT FROM AUTHOR]

The use of additives to improve the shortcomings of biofuels in application is one of the most economical and effective methods. In this study, a new type of tridentate higher alcohol acetoacetate aluminum chelate additive was synthesized originally and then synchronously used as pour point depressant and resistance reducing agent. The low temperature fluidity of biodiesel-diesel blends, including cloud point, cold filter plugging point and pour point could be reduced by the maximum of 6, 7 and 12 °C for B20 (20 vol% biodiesel + 80 vol% diesel), and 5, 5 and 9 °C for biodiesel after the treatment of higher alcohol acetoacetate aluminum chelate additive, named as C16-acac-Al. Furthermore, the impedance modulus determined by electrochemical impedance spectroscopy of the blends were greatly reduced after the treatment of C16-acac-Al, especially noiseless-free in the low frequency region, and the effects of temperature change on electrochemical impedance spectroscopy of treated blends was explored. At length, the mechanism on how the morphology of wax crystals affect electrochemical impedance spectroscopy of treated blends as well as the effect mechanism of the synthetic additives improving the low temperature fluidity of blends were put forward. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • PAOs were synthesized by three natural α-olefins and 1-hexadecene at ordinary temperature. • Evaluated the impact of renewable natural α-olefins on the cold fluidity of diesel fuel. • PAOs can effectively reduce the cold filter plugging point and solid point of diesel fuel. • Effects of molecular configuration of natural olefins on wax crystals were explored. • A novel mechanism to change wax crystallization behaviors by PAO is proposed. Pour Point Depressants (PPDs) are currently deemed the most efficacious methodology to enhance the low-temperature fluidity of diesel fuel. However, the majority of these PPDs present complications such as high costs, intricate synthesis procedures, and exhibit potential biotoxicity. To address these challenges, natural α-olefins (β-caryophyllene, limonene and camphene) with 1-hexadecene in varying ratios (5, 10, 15, 20, 25:1) were successfully polymerized at ordinary temperature as poly-α-olefine pour point depressant (PAO PPD), and designated as 1-hexadecane-β-caryophyllene (C16-SZX), 1-hexadecane-limonene (C16-NMX), 1-hexadecane-camphene (C16-KX). An in-depth examination was conducted on the cold filter plugging point (CFPP) and solid point (SP) of both untreated and PPD-added diesel. Subsequently, the finding clearly demonstrates that the CFPP and SP were separately reduced 10 and 32 °C in diesel treated with a molar ratio of 10:1 of C16-KX at the dosage of 2000 ppm. Meanwhile, a comprehensive study was undertaken to investigate the influence of natural α-olefins on the reduction of low-temperature fluidity in diesel fuel. The inhibitory impacts of natural molecular formations on wax crystals were meticulously scrutinized, particularly their roles in modifying the growth patterns of these crystals. Eventually, a novel mechanism by which poly-α-olefine alters the crystalline behavior of wax crystals is proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthesis of phosphorus free organic molybdenum additive. • Phosphorus free organic molybdenum additive greatly reduces wear volume. • The organic molybdenum additive has excellent anti-friction and anti-wear. • The lubrication mechanism of organic molybdenum additive was discussed. A phosphorus-free triazine-based organic molybdenum compound (DCDM) was designed and synthesized by using the click chemistry approach, and its friction-reducing and anti-wear properties were evaluated in PAO10 base oil. The results indicated that DCDM exhibited excellent tribological performance, with a reduction of approximately 35% in friction coefficient and about 46% in wear scar diameter, due to the synergy effect between Mo and S. Surface analysis by EDS and XPS revealed the formation of MoO 3 , Fe 2 (SO 4) 3 , FeS, and MoS 2 in the friction film. And it was furhter confirmed that the presence of MoS 2 in the friction film contributed most significantly to the enhancement of the friction-reducing and anti-wear properties of the developed triazine-based organic molybdenum compound in PAO10 base oil. [ABSTRACT FROM AUTHOR]

The poor cold flow property is one of the main obstacle factors in affecting the utilization of high proportion biodiesel blends in engines. In this study, methylcyclohexyl methacrylate–methacrylate copolymers (MCHMA-R1MC, R1 = C12, C14, C16, C18) were synthesized at various molar ratios by radical polymerization, and their structures were analyzed and characterized by FTIR, GPC, and 1H NMR. These resulting copolymers were used as the cold flow improvers for biodiesel/diesel blends in terms of cold filter plugging point (CFPP) and solid point (SP) measurement. Results showed that the CFPP and SP of B20 decreased to a varied extent after MCHMA-R1MC treatment. When the monomer ratio of was 1:7, MCHMA-C14MC (1:7) exhibited the greatest reduction on the CFPP and SP of B20 by 18 °C and 25 °C at 2000 ppm dosage. The effects of MCHMA-R1MC copolymers on crystallization behavior and morphology were studied through polarizing optical microscope, differential scanning calorimetry and viscosity–temperature curves. The results indicated that MCHMA-C14MC could effectively delay the aggregation of wax crystals and change their crystalline behavior by changing the crystal shapes and inhibiting the formation of large wax crystals and then lower the low-temperature viscosity of biodiesel blends; therefore, MCHMA-C14MC has proven to be a high-effective cold flow improver for the biodiesel blends. [ABSTRACT FROM AUTHOR]

To study the structure-activity relationship and obtain more high-efficiency CFIs, a series of poly(methacrylate-co-methacrylamide) with various pendants (C 14 MC-BnMAM, C 14 MC- DpMAM, and C 14 MC-TrMAM) were synthesized by the radical polymerization of tetradecyl methacrylate (C 14 MC) with N-benzylmethacrylamide (BnMAM), N-(diphenylmethyl)methacrylamide (DpMAM), and N-(triphenylmethyl) methacrylamide (TrMAM) at various molar ratios. The depressive effects and action mechanism of these CFIs of poly(methacrylate-co-methacrylamide) were studied. [Display omitted] • A series of methacrylate-methacrylamide copolymers with various benzene rings were synthesized as cold flow improvers for diesel. • The depressive effects of C 14 MC-BnMAM are better than that of C 14 MC-DpMAM, and C 14 MC-TrMAM. • C 14 MC-BnMAM (6:1) exerted the greatest reduction on SP and CFPP by 26 °C and 12 °C at 2000 ppm. • The depressive effects of copolymers decreased with the benzene ring number increase. Due to the excellent structural diversity, polymethacrylates was considered as the effective cold flow improvers (CFIs) for diesel. To investigate the structure–activity relationship and obtain more high-efficiency CFIs, a series of methacrylate-methacrylamide copolymers with various pendants (C 14 MC-BnMAM, C 14 MC-DpMAM, and C 14 MC-TrMAM) were synthesized by the radical polymerization of tetradecyl methacrylate (C 14 MC) with N-benzylmethacrylamide (BnMAM), N-(diphenylmethyl)methacrylamide (DpMAM) and N-(triphenylmethyl) methacrylamide (TrMAM) at various molar ratios. The depressive effects of these CFIs with different benzene ring number on the diesel were tested by cold flow properties. Results illustrated that the overall depressive effects of this three copolymers decrease with increase of the benzene rings number in the side-chain, and the order is as follows: C 14 MC-BnMAM > C 14 MC-DpMAM > C 14 MC-TrMAM As the monomer molar ratio up to 6:1, these CFIs exhibited the largest reduction on the solid point (SP) and cold filter plugging point (CFPP) of diesel. Thereinto, diesel treated with C 14 MC-BnMAM (6:1) exhibited best depressive effects at the optimal dosage of 2000 ppm, and the SP and CFPP have decreased by 26 °C and 12 °C, respectively. In addition, the performance mechanism of these CFIs in diesel and their low temperature crystallization behaviors were investigated by the rheological behavior, polarizing optical microscope, and differential scanning calorimeter. [ABSTRACT FROM AUTHOR]

[Display omitted] • Directly grown Cu/Co-MOF on the surface of NF as a template. • Hierarchical CuCo 2 O 4 @CoS-Cu/Co-MOF core-shell nanoflower are synthesized. • The material exhibits high electrochemical performance with brilliant cyclic performance. • The device delivers a large energy density of 73.29 Wh kg−1 at 849.94 W kg−1. Rational design of composite materials with unique core-shell nanoflower structures is an important strategy for improving the electrochemical properties of supercapacitors such as capacitance and cycle stability. Herein, a two-step electrodeposition technique is used to orderly synthesize CuCo 2 O 4 and CoS on Ni foam coated with Cu/Co bimetal metal organic framework (Cu/Co-MOF) to fabricate a hierarchical core-shell nanoflower material (CuCo 2 O 4 @CoS-Cu/Co-MOF). This unique structure can increase the electrochemically active site of the composite, promoting the Faradaic redox reaction and enhancing its electrochemical properties. CuCo 2 O 4 @CoS-Cu/Co-MOF shows a prominent specific capacitance of 3150 F g−1 at 1 A g−1, marvelous rate performance of 81.82% (2577.3 F g−1 at 30 A g−1) and long cycle life (maintaining 96.74% after 10,000 cycles). What is more, the assembled CuCo 2 O 4 @CoS-Cu/Co-MOF//CNTs device has an energy density of 73.19 Wh kg−1 when the power density is 849.94 W kg−1. It has unexpected application prospects. [ABSTRACT FROM AUTHOR]

The enhancement of cold flow properties (CFPs) and oxidative stability (OS) in biodiesel-diesel blends typically involves the use of pour point depressants and antioxidants. However, a scant number of additives are capable of manifesting both pour point depression and antioxidant functionalities concurrently. This study explored the grafting of syringic acid (SA), 3,5-di-tert-butyl-4-hydroxybenzoic acid (DTBHA), and gallic acid (GA) onto polymethacrylate (PMA) type copolymers, culminating efficacious copolymers, namely PTG-SA, PTG-DTBHA and PTG-GA. The findings reveal that with the addition of 1500 ppm of PTG-GA, the CFPP and PP of B20 (20 vol% soybean biodiesel+80 vol% diesel) decrease by 10 and 18 °C respectively, and with the addition of 2000 ppm, the induction period (IP) of B20 can be extended from 1.34 to 8.69 h. In contrast, the application of PTG-SA and PTG-DTBHA to B20 led to inferior OS and CFPs as compared to PTG-GA. The inherent scientific mechanism that underlies this performance discrepancy was thoroughly investigated, scrutinizing it through the lens of co-crystallization and nucleation processes. This research underscores the potential of post-modification of PMA type pour point depressants with antioxidants, a strategy that not only bolsters the CFPs of B20 but also confers antioxidant attributes to the pour point depressants. [Display omitted] [ABSTRACT FROM AUTHOR]

As an alternative energy source to petrochemical diesel, biodiesel has garnered considerable attention due to its green and renewable properties. Nevertheless, the inferior oxidative stability (OS) and unsatisfactory cold flow properties (CFPs) of biodiesel limited its commercial application. The objective of this study was to explored the potential of purified Ginkgo biloba L. leaf extract (GBLE) in improving the OS and CFPs of biodiesel-diesel blends (B20 and B30). The successful extraction of purified GBLE and its performance testing in the blends at the parts per million (ppm) level demonstrated its significant improvement effects. The results indicated that purified GBLE exhibited notable improvements in the OS and CFPs of both B20 and B30. In particular, 1250 ppm purified GBLE demonstrated the most substantial dual-functional improvement for both B20 and B30, increasing the induction period from 2.10 h to 10.93 h for B20, and from 1.02 h to 8.57 h for B30, meeting the EN 14112 standard. Additionally, it also decreased the cold filter plugging point of B20 and B30 by 10 °C and 7 °C, respectively, resulting in a 6 °C reduction for both pour point values. On the other hand, the conversion of discarded Ginkgo biloba L. leaves into valuable dual-functional additives has the potential to attract attention in the biodiesel industry. Hence, addition of purified GBLE appeared to be an effective and economically sustainable strategy to enhance OS and CFPs of the biodiesel-diesel blends (B20 and B30). [Display omitted] • Aqueous GBLE was made and purified through adsorption-desorption using HPD-100 macroporous resin. • 1250 ppm purified GBLE in B20 and B30 showed the most improvement in both OS and CFPs. • 1250 ppm purified GBLE enhances the IP from 2.1 h to 10.93 h for B20, lowering CFPP and PP by 10 °C and 6 °C. • 1250 ppm purified GBLE enhances the IP from 1.02 h to 8.57 h for B30, lowering CFPP and PP by 7 °C and 6 °C. • Explored antioxidant and pour point depression mechanisms of purified GBLE. [ABSTRACT FROM AUTHOR]

Sulfur free and environmentally friendly lubrication additives have been widely concerned in industrial applications. In this work, the α-Zirconium phosphate (α-ZrP) with two-dimensional nanomaterials and trioctyldodecyl phosphonium diisooctyl phosphate (P/P) were respectively prepared. Then, the composite lubricating additives containing P/P with α-ZrP were obtained. The synergistic effect of α-ZrP with P/P on the tribological properties in paraffin oil were systematically investigated. The results indicated that 1 %P/P@1000 α-ZrP additive exhibited excellent anti-friction and anti-wear properties. The improved tribological properties could be mainly attributed to the fact that the slip action of α-ZrP and its pronounced synergy effect with P/P on the friction film on the metal surface, forming a dual-layered lubrication film and greatly reduced the shear wear and abrasive wear. [Display omitted] • The composite lubricating additives containing phosphorus ionic liquid with nano two-dimensional α-ZrP were prepared. • The P/P@α-ZrP lubricant additive exhibited excellent synergistic effect on the anti-friction and anti-wear properties. • The effects of additive concentration of α-ZrP on the dispersion and tribological performance were investigated. • The lubrication mechanism of the synergistic interaction between phosphorus ionic liquid and α-ZrP was discussed. [ABSTRACT FROM AUTHOR]

• Tetradecylphosphonic acid (TDPA) modified zirconium-based MOF was prepared as a lubricant additive in soybean oil. • TDPA modification can significantly improve the aggregation of Zr-MOF. • TDPA-Zr-MOF shows excellent anti-friction and anti-wear properties. • The lubrication properties of TDPA-Zr-MOF are attributed to the rolling effect and the formation of a tough protective film. The development of novel high-performance lubricants is of great significance to reduce energy consumption and save energy. Herein, we report a zirconium-based MOF functionalized with tetradecylphosphonic acid (TDPA-Zr-MOF), as a lubricant additive in soybean oil (SO). The tribological properties of TDPA-Zr-MOF were systematically measured by a four-ball test machine, which showed that soybean oil with TDPA-Zr-MOF exhibit better tribological properties compared with pure soybean oil. The friction coefficient and wear scar diameter are significantly reduced, both of which can be decreased by more than 35%. Based on the analysis of morphology and chemical composition of the worn surface, it is concluded that the excellent anti-friction and anti-wear properties of TDPA-Zr-MOF attributed to rolling effect and protective film effect. [ABSTRACT FROM AUTHOR]

A porous carbon precursor is prepared by modifying polyvinylidene fluoride with nitrogen via a chemical polyreaction and then introducing mesopores using the soft-template method. After carbonization at the appropriate temperature, the obtained carbon material could be applied in supercapacitors without further treatment. The resulting material exhibits not only a comparatively stable nitrogen content that is very close to the nitrogen content of its precursor but also an effective hierarchical porous structure (~ 0.68 and ~ 4 nm). The large specific surface area of the carbon material (up to 1688 m2 g−1) is also an important factor influencing its excellent electrochemical performance. When tested using 6 M KOH as an electrolyte in a three-electrode system, CN-900 exhibits a specific capacitance of 355.6 F g−1 at 1 A g−1. When tested using the same electrolyte in a two-electrode system, CN-900 shows a specific capacitance of 84.08 F g−1 at 0.5 A g−1. In addition, the carbon material can maintain 98.4% capacitance after 8000 charge/discharge cycles at a current density of 2 A g−1. The performance of CN-900 is further tested in a two-electrode solid-state supercapacitor with sulfuric acid/polyvinyl alcohol as the electrolyte, and a specific capacitance of 90.31 F g−1 is observed at 1 A g−1. Therefore, the nitrogen-modified porous carbon is a very promising material with practical applications in supercapacitors. [ABSTRACT FROM AUTHOR]

A series of N/O co-doping porous carbon materials are fabricated from benzotriazole as nitrogen-containing precursor through simple chemical activation (phosphoric acid as activator) and thermolysis process under nitrogen atmosphere. Abundant heteroatoms or functional groups (O: 11.4 at.%; N: 6.5 at.%) in the N/O-3-700 sample can improve the overall electrochemical performance of the material, which is because they can enhance physicochemical properties and induce the pronounced pseudocapacitance. In three-electrode system, the resultant product (N/O-3-700) has a highest specific capacitance value of 357.8 F g−1 at 0.1 A g−1 and good cycle stability (remains more than 94% after 10000 at 1 A g−1), which are attributed to large specific area (1337.7 m2 g−1) and proper functional groups (the sum of N-5 and N-6 content: 42.2 at.%; quinone: 14.3 at.%, C=O and/or COOH: 16.0 at.%). And in symmetric two-electrode cell, the N/O-3-700//N/O-3-700 cell possesses highest energy density of 17.80 Wh kg−1 at 1 A g−1 and still has a high energy density (12.51 Wh kg−1) at 10 A g−1. Thus, the N/O-doped porous carbon can be used for supercapacitors. [ABSTRACT FROM AUTHOR]

• Explore the pyrolysis of inertinite with quantum chemical calculation and TG-DTG. • Liquefaction activity correlates with chemical bond strength in structural model. • Coals with different inertinite content also have a better liquefaction effect. Coal is heterogeneous, but the inertinite in coal is not conducive to liquefaction, resulting in a lower yield of coal-liquefied oil. Herein, to investigate the liquefaction performance of inertinite, two coal samples with different inertinite contents were obtained by the floating and sinking of coal: low-density inertinite (LDI) and high-density inertinite (HDI). Respectively, the pyrolysis characteristics and liquefaction properties of inertinite in raw coal, LDI and HDI were investigated using molecular structural models combined with quantum chemical calculations, thermogravimetric analysis (TGA), X-ray diffraction (XRD) and liquefaction tests. Quantum chemical calculations revealed that raw coal and LDI comprised more bonds with longer bond lengths and smaller bond orders than HDI. Form Bond-breaking analysis, various cyclic fragments of free radicals were obtained from the pyrolysis of raw coal were primarily monocyclic and bicyclic free radicals, the LDI were primarily binary and ternary annular fragments, and the HDI were mainly composed of quaternary ring fragments. The TGA results revealed that the thermal decomposition reactivity of LDI was comparable to raw coal and superior to HDI. XRD results revealed that the size and content of the aromatics in raw coal residue (RCR) and LDI and LDI residue (LDIR) increased in comparison with raw coal and LDI after liquefaction. The comparison of the liquefaction results of raw coal LDI and HDI revealed that coals with LDI instead of HDI exhibit better liquefaction performance. [ABSTRACT FROM AUTHOR]

The addition of pour point depressants (PPDs) represents the most direct and efficient approach for improving the cold-flow properties of diesel. Nevertheless, the high doses of additives have consistently been a constraining factor. To address this challenge, the study synthesized tetradecyl methacrylate–N-hydroxymethacrylamide–benzyl acrylate (C 14 MC–NMA–BA), tetradecyl methacrylate–N-hydroxymethacrylamide–4-pentenoic acid benzyl ester (C 14 MC–NMA–PB), and tetradecyl methacrylate–N-hydroxymethacrylamide–10-undecenoic acid benzyl ester (C 14 MC–NMA–UB) at various molar ratios (1:1:1, 5:1:1, 10:1:1, 15:1:1, and 20:1:1) as PPDs for diesel. The aim of these PPDs is to efficiently improve the cold-flow properties of diesel at low doses. The cold filter plugging point (CFPP) and solidification point (SP) of diesel were tested before and after treatment with PPDs. The results confirmed that C 14 MC–NMA–UB with longer carbon chains exhibited superior performance compared to C 14 MC–NMA–PB and C 14 MC–NMA–BA. Considering both cost-effectiveness and performance metrics, 400 ppm C 14 MC–NMA–UB (5:1:1) was identified as the optimal choice for significantly enhancing diesel cold-flow properties, leading to reductions of CFPP and SP by 11 °C and 25 °C, respectively. Furthermore, the study delved into the inhibitory mechanisms of PPDs by examining the crystallization behavior of diesel at low temperatures, utilizing techniques such as differential scanning calorimetry, viscosity-temperature profiles, and polarized optical microscopy. [Display omitted] • A series of benzene-containing ternary PMA-type PPDs was synthesized by copolymerization. • The inhibitory effect of copolymer depends on chain length of benzene monomer. • 400 ppm C 14 MC–NMA–UB (5:1:1) achieved an optimal suppression effect on diesel crystallization. • The crystallization behavior of PPDs on diesel fuel was investigated. [ABSTRACT FROM AUTHOR]

[Display omitted] • Grafted polymer with surfaced-modified nanosilica is applied. • Nanocomposite polymer improves diesel cold flow excellently. • Nanocomposite changes the crystallization behaviour of n-alkanes in diesel. • Heterogeneous nucleation is significance to improve diesel cold flow properties. Polymers with alkyl methacrylate as structural unit can significantly improve cold flow properties of diesel. Grafting polymers onto surface-modified nanomaterials can further enhance the low temperature fluidity of diesel. In this study, two molecules containing the structure of dicarboxylic anhydride were used as structural unit with tetradecyl methacrylate to synthesise the polymer pour point depressant (PPD). These polymer PPDs achieved excellent depressive effects, in particular, 1500 ppm of tetradecyl methacrylate–carbic anhydride (9:1) reduced the cold filter plugging point (CFPP) and solid point (SP) of diesel by 8 and 18 ℃, respectively. To further enhance the low-temperature fluidity properties of diesel, silane coupling agents were used to surface-modify nano silica, and then polymers were chemically grafted onto the surface-modified nano silica to prepare the nano PPDs. The well-dispersed nano PDDs achieved higher depressive effects than polymer PPDs on diesel. The diesel treated with 1500 ppm of tetradecyl methacrylate–carbic anhydride–surface modified nano silica (9:1:1) showed a decrease in CFPP and SP of 14 ℃ and 21 ℃, respectively. Transmission electron microscope was used to characterise the morphology and particle size of nano silica before and after surface modification and chemical grafting. The structural features of polymer PPDs and nano PPDs were analysed using fourier transform infrared spectroscopy, gel permeation chromatography and proton nuclear magnetic resonance. Finally, the n-alkane crystallisation habit and wax crystal growth habit of pure diesel and diesel treated with polymer and nano PPDs during cooling process were characterized using differential scanning calorimetry, polarising optical microscopy and rheometry. The effects of polymer and nano PPDs on the nucleation and growth patterns of n-alkanes in diesel were presented and the possible mechanism was inferred. [ABSTRACT FROM AUTHOR]

1. Synthetic route of copolymer. 2. Possible mechanism of (C16-AM, C16-IM and C16-SM) for improving the fluidity of diesel oil at low temperature. [Display omitted] • Comb-like PAOs were synthesized from long-chain olefin and benzene containing olefin. • Comb-like PAOs can effectively improve the low temperature cold flow of diesel fuel. • The properties of synthetic PAOs and commercial PPDs were compared during oxidation. • The crystallization behaviors of Comb-like PAOs were studied. Pour point depressants (PPDs) represent an efficient and economical approach to enhance diesel's low-temperature fluidity, yet their efficacy is influenced by molecular structure and surfactant moieties. To achieve highly effective PPDs, a series of comb-structured poly-alpha-olefins (PAOs) were synthesized in this paper, designated as 1-hexadecene-styrene (C16-SM), 1-hexadecene- allyl benzene (C16-AM), and 1-hexadecene-indene (C16-IM). The copolymers' impact on diminishing diesel's solid point (SP) and cold filter plugging point (CFPP) was thoroughly investigated. Notably, with a 1-hexadecene to styrene monomer molar ratio of 20:1, the most favorable inhibitory effect of C16-SM was observed, exhibiting a reduction of 10 °C for CFPP and 30 °C for SP. Comparing C16-SM to commercial pour point depressants (CPPDs) after subjecting them to an accelerated oxidation test revealed that the C16-SM performance was more stable under oxidative conditions. To address stability and environmental pollution concerns associated with PPDs, this study aims to develop a stable, eco-friendly PAO PPD and assess the influence of various benzene ring-based monomers on diesel's cold fluidity in low-temperature conditions. Furthermore, a novel mechanism elucidating the change in crystal morphology and size by PAOs is proposed. [ABSTRACT FROM AUTHOR]

Abstract The electrolysis of water to produce clean, non-byproduct hydrogen energy is considered to be the most effective method. Therefore, it is of far-reaching significance that hydrogen evolution electrocatalysts with lower development costs and good performance. In this essay, the different effects of Electrocatalytic Hydrogen Evolution of FeNi x S 2 - RGO Electrocatalysts are studied with different nickel-doped content added. The results demonstrate that the Ni element incorporated with a molar fraction of 10% (FeNi 0.10 S 2 -RGO) has a lower Tafel slope (71.96 mV dec−1) and good electrochemical kinetics. However, the Ni element with a mole fraction of 20% (FeNi 0.20 S 2 -RGO) has a low overpotential. Compared to FeNi 0.10 S 2 -RGO, the overpotential of FeNi 0.20 S 2 -RGO is reduced by 42 mV at the current density of 10 mA cm−2 in 0.5 M H 2 SO 4. Moreover, Fe and Ni are earth-abundant in content, inexpensive and suitable for industrial production. Graphical abstract Image 1 Highlights • We discussed the effect of FeNi x S 2 - RGO on the electrocatalytic hydrogen evolution of different Ni contents. • The FeNi x S 2 - RGO electrocatalyst we prepared has a very small electrochemical impedance. • FeNi x S 2 - RGO electrocatalyst exhibited good electrochemical kinetics and compared to FeNi 0.10 S 2 -RGO, the overpotential of FeNi 0.20 S 2 -RGO is reduced by 42 mV at the current density of 10 mA cm−2 in 0.5 M H 2 SO 4. [ABSTRACT FROM AUTHOR]

Abstract Hierarchical Ni–Mn Layered Double Hydroxide (Ni–Mn LDH) nanosheets grow on a nitrogen-doped carbon foam skeleton through a one-step hydrothermal reaction. LNCF-2 exhibits high specific capacitance (2128.3 F g−1 at 0.5 A g−1) and good cyclic stability (94.3% retention after 5000 cycles at 2 A g−1) as an electrode material for supercapacitors. Furthermore, as a positive electrode material for an asymmetric supercapacitors (ASCs), it also has a high specific capacitance (125.1 F g−1 at 0.5 A g−1) and an excellent cyclic stability (80.1% retention after 10000 cycles at 5 A g−1). The increase in electrochemical performance is attributed to the high Faradaic pseudocapacitance of Ni-Mn LDH and the introduction of three-dimensional carbon foam. Because the introduction of three-dimensional carbon foam can provide an interconnection network for electron and ion transfer, allowing efficient charge exchange. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

To investigate the influence of various pendants in comb-type copolymers on the low-temperature flowability of diesel fuel, a series of methacrylate-co-maleic anhydride copolymers R 1 MC-MA (R 1 = C 14 , C 16 , C 18 ) were synthesized. And C 14 MC-MA was aminated by R 2 NH 2 (R 2 = C 14 , C 16 , C 18 , phenyl, 1-naphthyl) to obtain a series of aminated copolymers C 14 MC-MA-a (C 14 MC-MA-14a, C 14 MC-MA-16a, C 14 MC-MA-18a, C 14 MC-MA-phenylamine, C 14 MC-MA-naphthylamine). They were characterized by Fourier transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance (1H NMR) and gel permeation chromatography (GPC). The influence of these pour point depressants (PPDs) on the cold flow properties of diesel fuel were investigated. The crystallization behavior and crystal morphology of diesel fuel were also studied by differential scanning calorimeter (DSC) and polarizing optical microscope (POM). When the dosage of PPDs was 1000 ppm, C 14 MC-MA-14a displayed an excellent depression on cold filter plugging point (CFPP) by 5 °C, C 14 MC-MA-phenylamine showed the best depression on solid point (SP) by 17 °C, and PPDC-1 (the mixture of C 14 MC-MA-14a with C 14 MC-MA-phenylamine) exhibited the best performance in depressing the CFPP and SP by 8 °C and 18 °C respectively. The results show that the effects of the PPDs on reducing SP and CFPP sometimes are inconsistent, because SP is closely related to the crystal/liquid interface, while CFPP is directly related to the wax crystal size. When pour point depressants are added, the wax crystals become smaller and regular (act as wax dispersants), thus inhibiting the formation of the porous network. So the CFPP decreased with decreasing the wax crystal size; and the SP first decreased with decreasing the wax crystal size, while when the wax crystals are too small, the large specific surface energy leads to the recovery of the SP. DSC and POM results showed that PPDs changed the crystallization behavior, size and shape of wax crystals, weakened the ability of wax crystals to form a three-dimensional network structure and made the wax crystals more uniform, compact, and dense. Therefore, the low temperature flowability of diesel fuel is improved by the synthesized pour point depressant. [ABSTRACT FROM AUTHOR]

Nitrogen-doped porous carbon is synthesised through a low-cost approach that utilise water chestnut as a carbon source and melamine as a nitrogen source through potassium hydroxide (KOH) activation for 2 h at 600 °C-900 °C. The obtained samples exhibit predominant characteristics with highly developed micropores, an ultralarge specific surface area (3401 m 2  g −1 ) and a high nitrogen content (4.89 at.%). These characteristics endow nitrogen-doped porous carbon with a high specific capacity of 346 F g −1 and a high energy density of 22.4 W h kg −1  at 0.5 A g −1 in 6 mol dm −3 KOH. It also exhibits an excellent cycling stability with a retention of nearly 97.6% capacity after 5000 cycles at 1 A g −1 . In addition, the unique pore structure and high nitrogen content of porous carbon provide an important contribution to CO 2 adsorption capacity, which can reach up to 6.0 mmol g −1 (at 0 °C and 1 bar) and 4.7 mmol g −1 (at 25 °C and 1 bar), and to high CO 2 /N 2 selectivity. Results show that the synthesised porous carbon exhibit considerable potential in electrochemical energy storage and solid adsorption. [ABSTRACT FROM AUTHOR]

Polymers and surfactants are increasingly applied to improve the cold flow properties of diesel fuel. However, their depressive effects are closely related to the molecular structure of the structuring units. In this study, the structural properties of surfactants were applied to synthesise a series of polymers consisting of tetradecyl methacrylate and ether compounds as structural units, with the long alkyl chain and ether compounds acting as hydrophobic and hydrophilic groups, respectively. The polymers consisting of tetradecyl methacrylate and ether compounds combined the advantages of polymers and surfactants in improving the cold flow properties of diesel. Besides, the effects of different functional groups, molar ratios and additive amounts on the improvement of diesel fuel low–temperature fluidity were investigated. The results indicated that 1500 ppm polymer with tetradecyl methacrylate and allyl glycidyl ether as structural monomers at a molar ratio of 6:1 as polymer pour point depressant (PPD) showed a greater enhancement of cold filter plugging point and solid point of diesel (ΔCFPP = 12 ℃, ΔSP = 17 ℃). The molecular structures of efficient pour point depressants were screened and the polymer composition was broadened. Finally, differential scanning calorimeter, rheological and polarising optical microscopy were used to analyse the changes in wax crystals size and morphology in pure diesel and diesel treated with polymer PPDs, and a mechanism for polymer PPDs with surfactant structural properties to change the crystallisation and aggregation behaviour of wax crystals was inferred. [Display omitted] [ABSTRACT FROM AUTHOR]

Poor cold flow properties (CFPs) and oxidative stability (OS) are the major factors limiting the large-scale commercialization of biodiesel-diesel blends. In this study, the binary copolymers of high carbonyl methacrylate-cyclohexyl vinyl ethers (RMC-CVE, R = -C 12, -C 14, -C 16, -C 18) and ternary copolymers of tetradecyl methacrylate-cyclohexyl vinyl ethers-vanilla acrylate (C 14 MC-CVE-VAA) were synthesized as bifunctional additives of cold flow improver and antioxidant to address the poor CFPs and OS of waste cooking oil biodiesel (WCOB)-diesel blends. The effects of these copolymers on the solid point (SP), cold filter plugging point (CFPP) and induction period (IP) of B20 (20 vol% WCOB + 80 vol% diesel) were systematically studied. Results demonstrated that binary copolymer of C 14 MC-CVE (9:1) exerted the greatest reductions in SP and CFPP by 15 °C and 10 °C, respectively, at a dosage of 2000 ppm, yet it had no significant improvement in the OS of B20. The introduction of third monomers of VAA obviously enhanced the improvement effect on the CFPs and OS of B20, so the ternary copolymers of C 14 MC-CVE-VAA seem to be an efficient bifunctional additive for biodiesel-diesel blends. At the same dose of 2000 ppm, C 14 MC-CVE-VAA (9:1:1) presented the better improvement on SP and CFPP of B20 by 17 °C and 11 °C, respectively. Also, the IP of B20 was improved from 1.50 h to 7.46 h. Lastly, the mechanism of the bifunctional additive on improving the CFPs and OS of B20 was investigated by polarizing microscope, viscosity-temperature curve analysis, differential scanning calorimetry, DPPH radical scavenging experiment, and the Rancimat method. [Display omitted] • A tetradecyl methacrylate-cyclohexyl vinyl ether-vanilla acrylate copolymer (C 14 MC-CVE-VAA) was prepared as a bifunctional additive for biodiesel blends. • C 14 MC-CVE-VAA (9:1:1) exhibited optimal improvements on the cold flow properties (CFPs) and oxidative stability (OS) at 2000 ppm dosage. • The possible mechanisms of crystallisation inhibition and antioxidant activity of C 14 MC-CVE-VAA (9:1:1) in biodiesel blends were discussed. [ABSTRACT FROM AUTHOR]

CoMn-layered double hydroxide (LDH) nanowires are successfully embedded on the surface of nickel foam (NF) through a simple one-step hydrothermal method. The morphology and electrochemical properties of the samples can be controlled using different molar ratios of Co and Mn salts. CoMn LDH nanowires on NF with Co 2+ /Mn 2+ molar ratio of 3:1 exhibit excellent electrochemical properties, high specific capacitance (1409 F g −1 at current density of 1 A g −1 ), good cycling stability (93.2% retention after 3000 charge-discharge cycles), and excellent performance rate (71.1% retention at 10 A g −1 ) when used as an electrode material for supercapacitors. [ABSTRACT FROM AUTHOR]

• The structure model for long flame coal was elaborately constructed. • The bond order information of molecular structures were ascertained. • The rationality of the structure model was verified. This study amis to study the coal structure model by quantum chemistry calculations and the separation of coal liquefied oil group components. Ultimate analysis, Proximate analysis, and maceral analysis, along with Infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and nuclear magnetic resonance carbon spectroscopy (13C CP/MAS NMR) were used to develop the Jinjitan coal structural model. Molecular structures bond order was determined through the use of quantum chemical calculations. The most difficult bonds to break, according to our investigations, were those between aromatic structures and carboxyl or carbonyl groups. An autoclave liquefaction experiment and a group component separation experiment were conducted in an effort to further confirm the structural information and gain a deeper grasp of the characteristics of coal liquefaction oil. The gas chromatography-mass spectrometry (GC–MS) indicated that polycyclic aromatics, due to their greater molecular weight, exhibited peaks with a longer retention duration. As well, quantum chemistry calculations revealed the structure of the small molecule after the broken bond, which wasverified in the aromatic and saturated hydrocarbons after the separation of coal liquefied oil group components. [ABSTRACT FROM AUTHOR]

TiO 2 nanotube arrays (NTAs) are excellent energy storage materials due to their chemical stability, high specific surface area and wide voltage window. However, poor electrochemical activity and electrical conductivity limit the application in supercapacitors. Herein, we develop a promising modification strategy for improving electrochemical performance of TiO 2 , through bulk-phase Nb-doping by in-situ anodization of Ti-Nb alloy and surface self-doping of Ti3+/oxygen vacancy (V o) with one-step electrochemical reduction. Material characterizations indicate the successful formation of Nb5+ in the lattice, as well as Ti3+/V o and hydroxyl are also introduced. Electrochemical measurements demonstrate that reduced co-doping system (denoted as R-Ti-Nb-O) yields a superior areal capacitance (19.56 mF cm−2 at 0.1 mA cm−2), which enhances by 3 orders of magnitude compared with pristine TiO 2. Furthermore, R-Ti-Nb-O exhibits high energy density (1.33 mWh cm−2), superior power density (35 mW cm−2), outstanding rate capability (81.70%) and remarkable cycling stability (76.76% capacitance retention after 1000 cycles). Density functional theory (DFT) calculations further reveal that reduced co-doping system indeed significantly increases the carrier density, electrical conductivity and hydrophilicity. This work involving bulk-phase Nb-doping and surface oxygen defective engineering may help provide a feasible and effective strategy to improve areal capacitance of Ti-based nanostructures for enhanced electrochemical energy storage. [ABSTRACT FROM AUTHOR]

Blending biodiesel with petrochemical diesel is an effective method to alleviate the global petrochemical energy shortage, but the application of biodiesel-diesel blends is always hindered by the worse cold flow properties. To resolve this issue, a series of methacrylate-hydroxyethyl methacrylate copolymers (RMC-HEMA, R= -C 12 , -C 14 , -C 16 , -C 18) with different molar ratios were synthesized as pour point depressants (PPDs) for B20 (20 vol% biodiesel + 80 vol% diesel). C 14 MC-HEMA (9:1) showed better cold flow performance at 1000 ppm, reducing the solid point (SP) and cold filter point (CFPP) of B20 by 14 °C and 6 °C, respectively. To obtain higher-efficiency PPDs, two polymers of poly alpha olefin (PAO) and ethylene vinyl acetate copolymer (EVA), as the assistants, were combined with C 14 MC-HEMA (9:1) in different mass ratios. Results showed that when the weight ratio of C 14 MC-HEMA (9:1) to PAO was 5:1, the SP and CFPP of B20 decreased by 18 °C and 14 °C at 1000 ppm. Compared to the single C 14 MC-HEMA (9:1), the SP and CFPP were decreased by 4 °C and 8 °C, respectively. Subsequently, polarizing optical microscopy, differential scanning calorimeter and viscosity-temperature curves were conducted to explore the anti-coagulating mechanism of these PPDs in improving the cold flow fluidity of B20. • Tetradecyl methacrylate-hydroxyethyl methacrylate copolymers (RMC-HEMA, R= -C 12 , -C 14 , -C 16 , -C 18) were synthesized as PPDs for biodiesel blends. • Poly alpha olefin (PAO) and ethylene-vinyl acetate copolymer (EVA) were combined with C 14 MC-HEMA (9:1) to obtain higher depressive effects. • C 14 MC-HEMA (9:1) combined with PAO in 5:1 showed the greatest reduction on SP and CFPP of B20 by 18 °C and 14 °C. • The synergistic mechanism of C 14 MC-HEMA (9:1) and PAO in biodiesel blends was discussed. [ABSTRACT FROM AUTHOR]

• Two types phenolic acids were grafted on the ethylene–vinyl acetate (EVA) copolymers with different VA contents to improve the cold flow properties (CFPs) and oxidative stability (OS) of B20. • Bio-based GA-grafted EVA showed better improvement effects than that of commercial DTBHA. • EVA-GA-2 exhibited better effects on the CFPs and OS at 0.1 wt% dosage, and the cloud point (CP), pour point (PP), and cold filter plugging point (CFPP) reduced by 5 °C, 10 °C, and 11 °C, respectively. The induction period (IP) increased from 1.66 h to 25.56 h. • The possible action effects of improving CFPs and OS were discussed. Poor cold flow properties (CFPs) and oxidative stability (OS) are the main commercial obstacles affecting the application of biodiesel. Most additives only improve a single specific property. In this study, a bifunctional additive was prepared to improve the CFPs and OS of waste cooking oil (WCO) biodiesel blends. 3,5-di- tert -butyl-4-hydroxybenzoic acid (DTBHA) and gallic acid (GA) were grafted on the ethylene–vinyl acetate (EVA) copolymers with different VA contents, and the grafted EVAs were used as the cold flow improvers and antioxidants for B20 (20 vol% WCO biodiesel + 80 vol% diesel fuel). EVA with 25 % VA content (EVA-2) at 0.15 wt% dosage exhibited better reduction on cloud point (CP), pour point (PP), and cold filter plugging point (CFPP) by 5 °C, 7 °C, and 10 °C, respectively. The EVA had depression effects on the CFPs of B20, whereas it had no effects on OS. The EVA presented further improvement on the CFPs and OS of B20 after the grafting of phenolic acids. Bio-based GA-grafted EVA showed better improvement effects than that of commercial DTBHA. EVA-GA-2 exhibited better effects on the CFPs and OS at an optimal dosage of 0.1 wt%, and the CP, PP, and CFPP reduced by 5 °C, 10 °C, and 11 °C, respectively. The induction period increased from 1.66 h to 25.56 h. The effects of the bifunctional additive on CFPs and OS of B20 were discussed. [ABSTRACT FROM AUTHOR]