Conventional Sulfur Research Articles

Ab Initio Simulation of Raman Fingerprints of Sulfur/Carbon Copolymer Cathodes During Discharge of Li-S Batteries.

Sulfur/carbon copolymers have emerged as promising alternatives for conventional crystalline sulfur cathodes for lithium-sulfur batteries. Among these, sulfur--n--1,3--diisopropenylbenzene (S/DIB) copolymers, which present a 3D network of DIB molecules interconnected via sulfur chains, have particularly shown a good performance and, therefore, have been under intensive experimental and theoretical investigations. However, their structural complexity and flexibility have hindered a clear understanding of their structural evolution during redox reactions at an atomistic level. Here, by performing state-of-the-art ab initiomolecular dynamics-based Raman spectroscopy simulations, we investigate the spectral fingerprints of S/DIB copolymers arising from local structures during consecutive reactions with lithium. We discuss Raman spectral changes in particular frequency ranges which are common in S/DIB copolymers having shortand those consisting of longer sulfur chains. We also highlight those spectroscopic fingerprints specific to local S/DIB structures containing only short or long sulfur chains. This could help distinguish them experimentally during discharge. Our theoretically predicted results are in a good agreement with experimental Raman measurements on cells at different discharge stages. This work representsan attempt to compute Raman fingerprints ofcopolymer cathodes during battery operationincluding quantum-chemical and finite-temperature effects, and provides a guideline for Raman spectral changes of arbitrary electrodes during discharge.

Sulfidation of Smithsonite via Microwave Roasting under Low-Temperature Conditions

This study employs microwave roasting to decompose smithsonite mineral (zinc carbonate) into zinc oxide, which then reacts with pyrite to sulfurize its surface, forming zinc sulfide. This process is beneficial for the flotation recovery of zinc oxide minerals. The surface sulfidation behavior of smithsonite under low-temperature microwave roasting conditions is examined through X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and thermodynamic calculations. XRD and thermodynamic analysis indicate that smithsonite completely decomposes into zinc oxide at 400 °C. Introducing a small amount of pyrite as a sulfidizing reagent leads to the formation of sulfides on the surface of decomposed smithsonite. XPS analysis confirms that the sulfide formed on the surface is zinc sulfide. SEM analysis reveals that sulfides are distributed on the surface of smithsonite, and the average sulfur concentration increases with the pyrite dosage. Microwave-assisted sulfurization of smithsonite (ZnCO3) was found to significantly enhance its floatability compared to conventional sulfurization methods. The optimal mass ratio of ZnCO3 to FeS2 is approximately 1:1.5, with the best temperature being 400 °C. These findings provide a technical solution for the application of microwave roasting in the efficient recovery of smithsonite through flotation.

A chemical interpretation for the post-reversion upturn in the natural rubber/accelerated sulfur system based on the viscoelastic properties and cross-link density measurements

The curing cycle of natural rubber (NR) with a conventional accelerated sulfur system (CV) generally exhibits three phases. The induction phase, the crosslinking phase, and the reversion phase. Prolonged curing of NR/CV system even at a temperature of 150 °C can show reversion. Many research reports are available in the literature with reference to the reversion behavior and the subsequent network modifications of natural rubber with accelerated sulfur. However, the literature regarding post-reversion curing behavior is scanty. This article describes the post-reversion upturn of natural rubber with a conventional accelerator sulfur system at a higher curing temperature. A network rebuilding after collapsing the initially formed network due to reversion was identified as the primary reason for the post-reversion upturn. The dynamic rheological testing capability of the Rubber Process Analyzer (RPA) was employed to characterize the network formed during curing, reversion and post-reversion phases. The cure-strain sweep data from the RPA indicated that the shear storage modulus (G′) of the broken network increased due to the post-reversion upturn. The chemical crosslink densities of the samples were also found to increase due to the upturn curing behavior. From these experimental results and the information conceived from the previous literature, two plausible mechanisms have been proposed to interpret the post-reversion upturn cure behavior.

Water‐Soluble Ionic Liquid‐Containing Sulfur Polymers for Mercury Capture, Demulsification, and Antibacterial Activity

AbstractSulfur polymers, prepared by inverse vulcanization using elemental sulfur and vinylic monomers, are emerging functional materials of current research interest; however, sulfur polymers suffer from limited water solubility due to the hydrophobic nature of conventional comonomers and sulfur. Herein, the preparation of ionic liquid (IL)‐containing sulfur polymers are reported using the hydrophilic ionic liquid, 1‐allyl‐3‐vinylimidazolium chloride (AVImCl) as a comonomer. The introduction of IL significantly enhances the hydrophilicity of sulfur polymers, enabling them to dissolve in water. Benefiting from the thorough contact with aqueous mercury ions, the resultant sulfur polymer possesses high uptake capacity (436 mg g−1). After binding mercury, a coordination complex is formed and precipitated. The charged sulfur polymers gain a new application in demulsification. The polymer quickly breaks oil‐in‐water (O/W) emulsions through anion exchange between Cl− of the polymer and dodecylbenzenesulfonate (DBS−) of the surfactant. In addition, the polymer has a growth inhibitory effect against Staphylococcus aureus. The integration of IL and elemental sulfur provides a novel approach to modifying the wettability of sulfur polymers. Also, this novel water‐soluble IL‐containing sulfur polymer, with mercury capture, demulsification, and antibacterial activity, can be considered as a multifunctional material in practical water purification.

Cu2ZnSnS4 formation by laser annealing in controlled atmosphere

Laser annealing is an attractive process to form high-quality semiconductor films because of localized annealing area and short annealing time. In a previous study, a Cu2ZnSnS4 (CZTS) polycrystalline semiconductor film was realized using laser annealing in air as a light absorption layer for solar cells, although the crystallization was not sufficient in comparison with CZTS formed by the conventional thermal sulfurization process. In this study, we demonstrate a newly developed gas-atmosphere-controlled laser annealing system. A Cu–Zn–Sn–S-based precursor was formed, followed by laser annealing of the system. Laser annealing in air, Ar, and 5% H2S/Ar gas was performed to investigate the influence of the gas species on the crystallization of the precursor. A 5% H2S/Ar atmosphere promoted the crystallization of CZTS with the suppression of S desorption and Cu sulfide formation, while air and Ar atmospheres allowed the formation of Cu sulfide.

Anti-aging effect of TMQ on EPDM for Various Cure Systems

Ethylene propylene diene rubber (EPDM) is a common raw material for weather resistant rubber products used in lots of areas such as cable, automotive, marine industry and aviation applications. Superior processing behaviour, electrical properties and moderate high temperature resistance also make EPDM an attractive raw material for a wide range of further industrial performance requirements. As well as the other general purpose rubbers, EPDM needs to be protected against thermo-oxidative aging. Short and long term aging behaviour of both sulphur and peroxide cured EPDM has been studied in literature. However, to the authors’ best knowledge, there is not any study in literature systematically evaluating a common rubber antioxidant 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ) for investigating theoretical life-time of EPDM based materials that were vulcanized with different crosslinking systems. In this study, effects of TMQ on the thermo-oxidative resistance of EPDM has been studied for conven-tional and efficient sulphur vulcanization systems as well as peroxide vulcanization system. Aging mechanism for different cases has been investigated by using structural, rheological and mechanical tests. Thermo-oxidative aging has been monitored by carbonyl index and activation energy. Arrhenius based life-time estimation methodology has also been employed to evaluate aging behaviour of the reference and TMQ containing (-T) compounds. TMQ was found to exhibit different levels of protection against thermo-oxidative aging for all the curing systems and at all aging conditions. Higher aging activation energy for -T compounds has been attributed to extended service life of the material in the presence of TMQ.

Response studies of nano-sulphur on nutrient uptake, sulphur fractions, yield and quality parameters of peanut (Arachis hypogaea L.)

An attempt was made to study the response of nano-sulfur in groundnut using four levels of nano-sulfur (NS) and conventional sulfur (CS) fertilizers in a completely randomized block design and replicated thrice. The results indicated that application of nano-sulfur @ 30 kg S ha−1 recorded 0.76 mg root sulfur uptake plant−1, 40.5 mg shoot sulfur uptake plant−1, 14.9 mg kernel sulfur uptake plant−1, and 3.09 mg shell sulfur uptake plant−1 higher in comparison to conventional sulfur @ 40 kg S ha−1 recorded root, shoot, kernel and shell sulfur uptake of 0.53, 35.8, 11.4 and 2.46 mg plant−1, respectively. The highest pod yield was recorded at 12.4 g plant−1 with nano-sulfur application @ 30 kg S ha−1 when compared to conventional sulfur @ 40 kg S ha−1 registered at 10.7 g plant−1. Quality parameters such as oil, crude protein, methionine, cysteine, and total free amino acid content were recorded highest under nano-sulfur application @ 30 kg S ha−1 i.e. 48.3%, 27.2%, 3.44 mg g −1, 1.89 mg g−1 and 46.3 mg g−1 respectively whereas conventional sulfur @ same set of sulfur treatment observed (46.7% oil, 25.1% crude protein, 3.16 mg methionine g−1, 1.75 mg cysteine g−1, and 39.6 mg total free amino acids g−1. Finally, the results concluded that the application of nano-S @ 30 kg S ha−1 is sufficient to attain higher sulfur use efficiency with a reduction of sulfur fertilizer to the tune of 25% besides augmenting the soil sulfur reserve without harming the environment.

Long-term stability of lithium–sulfur batteries via synergistic integration of nitrogen-doped graphitic carbon-coated cobalt selenide nanocrystals within porous three-dimensional graphene-carbon nanotube microspheres

Three-dimensional porous microspheres consist of highly conductive reduced graphene oxide-carbon nanotube (rGO‒CNT) framework with well-embedded cobalt selenide (CoSe2) nanocrystals coated with N-doped graphitic carbon (NGC) were synthesized (referred as “P–CoSe2@NGC/rGO‒CNT” microspheres) and utilized as an electrocatalytic interlayer to enhance the performance of lithium-sulfur (Li–S) batteries. The incorporation of the NGC layer and rGO‒CNT framework not only enhances the electronic conductivity significantly but also offers numerous conductive pathways (primary and secondary) for efficient electron transport. Macropores (φ = 100 nm) formed by the decomposition of PS nanobeads (φ = 200 nm) guarantee effective electrolyte penetration and short diffusion pathways. Moreover, the CoSe2 nanocrystals offer a multitude of polar active sites that effectively anchor polysulfide intermediates, reducing the loss of active material. Benefiting from the nanostructure merits, Li–S cells featuring a P–CoSe2@NGC/rGO‒CNT-coated separator and a conventional sulfur electrode demonstrated outstanding rate capability (up to 2.0 C) and remarkable cycling stability (1000 cycles at 2.0 C). Even under more demanding cell conditions, such as high sulfur content (71 %), high sulfur loading (4.6 mg cm−2), and low E/S (5.6 μL mg−1) ratio, the cell exhibits impressive cycling stability with 420 cycles at 0.1 C, along with feasible rate performance up to 0.3 C.

Routes to Electrochemically Stable Sulfur Cathodes for Practical Li-S Batteries.

Lithium-sulfur (Li-S) batteries have been investigated intensively as a post-Li-ion technology in the past decade; however, their realizable energy density and cycling performance are still far from satisfaction for commercial development. Although many extremely high-capacity and cycle-stable S cathodes and Li anodes are reported in literature, their use for practical Li-S batteries remains challenging due to the huge gap between the laboratory research and industrial applications. The laboratory research is usually conducted by use of a thin-film electrode with a low sulfur loading and high electrolyte/sulfur (E/S) ratios, while the practical batteries require a thick/high sulfur loading cathode and a low E/S ratio to achieve a desired energy density. To make this clear, the inherent problems of dissolution/deposition mechanism of conventional sulfur cathodes are analyzed from the viewpoint of polarization theory of porous electrode after a brief overview of the recent research progress on sulfur cathodes of Li-S batteries, and the possible strategies for building an electrochemically stable sulfur cathode are discussed for practically viable Li-S batteries from the authors' own understandings.

Synthesis and characterization of Nano sulphur: Exploring its potential as slow release fertilizer

Sulphur is rapidly being recognized as the fourth key nutrient for plants after nitrogen, phosphorus, and potassium. It functions in several critical metabolic and physiological processes, such as Chlorophyll synthesis, Protein synthesis, Activation of enzymes, Stress tolerance and Seed production. In this background, an attempt was made to synthesize nano sulphur fertilizers for slow release using the reverse microemulsion (water-in-oil microemulsion) technique. Cyclohexane was used as oil phase. Tween-80 and ethanol were used as surfactant and co-surfactant, respectively. Hydrochloric acid and sodium polysulfide solution acted as an aqueous phase. This technique resulted in the successful synthesis of nano sulphur fertilizer. The sulphur nano fertilizer was characterized using X-ray diffraction (XRD), Fourier-Transform infrared spectroscopy (FT-IR), Scanning electron microscope (SEM) and Thermogravimetric analysis (TGA). The XRD pattern revealed the orthorhombic nature of nano sulphur and the lattice face-centred. The FTIR spectra at 1406 cm-1 confirmed the sulphur vibrations. The microemulsion method yielded stable, uniform, spherical nano sulphur particles with dimensions ranging from 25 to 47 nm. The thermal disintegration between 117°C to 122°C in TGA graph was attributed to the sublimation of sulphur in orthorhombic crystalline form, indicating the successful synthesis of nano sulphur. A laboratory study on nano sulphur fertilizer and conventional sulphur fertilizer was studied with a Percolator reaction system to evaluate the slow release of sulphur from both fertilizers at ambient temperature. Percolation reactor experiment indicated that sulphate release from nano sulphur was longer for 42 days than gypsum amended soil which exhausted within 35 days. Hence, synthesized nano sulphur fertilizer maximizes nutrient retention, eliminates environmental nutrient loses and decreases fertilizer requirements.

Electrolyte Design for Intermediate-Temperature Na-S Batteries with High Energy Density

The conventional high-temperature sodium sulfur battery is an attractive technology for grid-level energy storage due to its low cost, high energy density and long cycle life. However, this system operates at 300-350 oC, which not only increases cost, but also accelerates degradation and causes potential safety issues. On the other side, Na-S batteries working at intermediate temperatures (e.g., 100-150 oC) have a much worse kinetics due to the formation of solid Na2S2 and Na2S with low ionic diffusivity and electronic conductivity. In this study, we have developed a new electrolyte solvent that can dissolve all sulfides and polysulfides, which avoids the poor kinetics in Na2S2 and Na2S, and allows Na-S batteries to operate at ~75 oC. Based on the 1 molL−1 sulfur catholyte, a high specific capacity of 1640 mAhg−1 is achieved at 0.13 mAcm−2. When increased to the 4 molL−1, the capacity is achieved 830 mAhg−1 and decays only 0.029%/cycle over 250 cycles at 1 mAcm−2. Such a system has potential applications for long-duration energy storage.

Chiral Sulfur Nanosheets for Dual-Selective Inhibition of Gram-Positive Bacteria.

Elemental sulfur is the oldest known antimicrobial agent. However, conventional sulfur in the clinic suffers from poor aqueous solubility and limited antibacterial activity, greatly hindering its practical use. Herein, we report a reform strategy coupling dimension engineering with chirality transfer to convert conventional 3D sulfur particles into chiral 2D sulfur nanosheets (S-NSs), which exhibit 50-fold improvement of antibacterial capability and dual-selective inhibition against Gram-positive bacteria. Benefiting from the inherent selectivity of S-NSs and chirality selectivity from decorated d-histidine, the obtained chiral S-NSs are proven to precisely kill Gram-positive drug-resistant bacteria, while no obvious bacterial inhibition is observed for Gram-negative bacteria. Mechanism studies reveal that S-NSs produce numerous reactive oxygen specipoes and hydrogen sulfide after incubation with bacteria, thus causing bacterial membrane destruction, respiratory chain damage, and ATP production inhibition. Upon spraying chiral S-NSs dispersions onto MRSA-infected wounds, the skin healing process was greatly accelerated in 8 days due to metabolism inhibition and oxidative damage of bacteria, indicating the excellent treatment efficiency of MRSA-infected wounds. This work converts the traditional well-known sulfur into modern antibacterial agents with a superior Gram-selectivity bactericidal capability.

Syntheses and dyeing properties of novel water‐soluble reactive sulphur black dyes

AbstractThe practical application of a sulphur black dye relies on its ability to dye cotton fibres with pure black colour and maintain the colour with high light fastness. Here, we report a synthesis method to prepare a novel water‐soluble reactive sulphur black dye. The approach involves the reduction of CI Sulphur Black 1 to its leuco form and subsequent reaction with a water‐soluble intermediate containing reactive groups synthesised from amino acid and cyanuric chloride. The optimal carboxyl and reactive group content of the water‐soluble reactive sulphur black dye is 141 mmol/100 g, and the water solubility can reach 92 g/L. The fixation of the reactive sulphur black dye on cotton reaches 89% in a pad dyeing process without using sodium sulphate. The reactive sulphur black dye can achieve a light fastness of grade 6‐7, a dry rub fastness of grade 4 and a wet rub fastness of grade 2, comparable or higher than the conventional CI Sulphur Black 1. The dyeing results showed that the novel water‐soluble reactive sulphur black dye has excellent performance and good application prospects.

Development of Multifunctional Cathode Binder via Inverse Vulcanization for Lithium–Sulfur Battery with Enhanced Capacity Retention

Vinyl-benzaldehyde (VB) monomers containing four functional groups were newly synthesized using the Williamson ether synthesis method. The two aldehyde groups of the synthesized monomers were able to react with amine-terminated macromonomers to form flexible networks. In addition, the two vinyl groups were found to be capable of inverse vulcanization with sulfur by conducting qualitative chemical analysis. The lithium–sulfur battery prepared using the VB-based cathode binder achieved high specific capacity with excellent capacity retention compared to conventional sulfur batteries, demonstrating the potential of the new binder.

Agricultural Residues as Potential Diluents in Natural Rubber Formulation

Agricultural residues such as Maize Husk, Groundnut Shell, Coconut Shell and Sugarcane Bagasse were collected, sorted, dried and ground to particulate fillers. The various fillers were characterized in terms of density, moisture content and pH value. Single ordinates of 150 µm particle size and 30 parts per hundred of rubber (pphr) loading were respectively adopted for all filler types. They were used alongside with conventional Sulphur vulcanization system (high Sulphur to low organo-accelerator level) in the formulations of natural rubber compounds. Tests such as tensile strength at 400% elongation, constant force compression set, abrasion resistance as a function of percentage mass retention on surface exposure to a rotating abrasive surface and thermal stability using differential scanning calorimeter were carried out. Results obtained revealed that rubber vulcanizate samples filled with coconut shell and sugarcane bagasse had hardness values of 58 and 57 on Shore A scale while unfilled vulcanizate and carbon black filled sample had respective values of 45 and 49 Shore A hardness. However, unfilled vulcanizate and carbon black filled vulcanizate showed superior values of tensile strength at 400% elongation to the ones filled with agricultural residues. Therefore, these agricultural residues can serve as diluents in the formulation of rubber vulcanizates.

Modelling the Mechanism of Sulphur Evolution in the Coal Combustion Process: The Effect of Sulphur–Nitrogen Interactions and Excess Air Coefficients

The efficient use of coal resources and the safe operation of coal-fired boilers are hindered by high-temperature corrosion caused by corrosive sulphur components. To predict the impact of sulphur–nitrogen interactions on sulphur’s evolution and its mechanism of action, a conventional sulphur component evolution model (uS–N) and an improved sulphur component evolution model (S–N) that considers sulphur–nitrogen interactions were proposed in the present study. The models were built using OpenFOAM–v8 software for the coal combustion process, and the generation of SO2, H2S, COS, and CS2 was simulated and analysed under different air excess coefficients. The simulations were conducted to analyse the patterns of SO2, H2S, COS, and CS2 generation at different air excess factors. The results show that, compared with the uS–N condition, the simulated values of coal combustion products (SO2, H2S, COS, and CS2) under the S–N condition were closer to the experimental values, and the errors of different sulphur components at the furnace exit were all less than 5%. As such, the S–N model can more accurately predict the evolution of sulphur components. In the simulation range, when the air excess factor increased from 0.7 to 0.9, the production rate of SO2 increased, while the production rates of corrosive sulphur components H2S, COS, and CS2 decreased significantly by 41.3%, 34.8%, and 53.8%, respectively. Further, the mechanism of the effect of sulphur–nitrogen interactions on the generation rates of different components was revealed at different air excess coefficients. Here, the effect of sulphur–nitrogen interactions on SO2 and COS was found to be more significant at smaller air excess coefficients, and the effect of sulphur–nitrogen interactions on H2S and CS2 was more significant at larger air excess coefficients. The present study can provide a theoretical basis for predicting the evolution of sulphur components during coal combustion and improving the high-temperature corrosion problems caused by such a process.

Investigation of poly(3,6-dioxa-1,8-octane-dithiol)-based organosulfur polymer as the positive electrode material in rechargeable Li-S battery

The lithium-sulfur batteries (LISB) possess issues, such as insulating nature of sulfur, polysulfide shuttle, volume expansion and self-discharge, which impede its widespread commercialization. To address the insulating nature of sulfur, carbon-based materials were utilised. However, increasing the amount of carbon content in the cathode matrix reduces the specific capacity and the gravimetric energy density. To address the above-mentioned issues, we believe that these can be overcome by developing or utilising sulfur confining materials, favourably macromolecules, so-called organosulfur polymers, as suitable candidates and potential solution. Hence, we developed a sulfur rich organosulfur based polymer, sulfur-poly(3,6-dioxa-1,8-octane-dithiol) (PSDODT) via an inverse vulcanization reaction, as well as by changing the feed composition, and thus the sulfur content of the polymer. Then, the synthesized PSDODTs with various weight ratios of sulfur and DODT (30:70, 40:60, and 50:50) were used as an alternative to elemental sulfur, and these were also mixed with carbon host materials, such as carbon black (CB) and reduced graphene oxide (rGO). Subsequently, the electrochemical performances of these materials were evaluated as cathode materials for Li-sulfur batteries. Among the developed cathode materials, the 40S:60DODT-rGO composite showed enhanced specific capacity with good cyclic performances in comparison to the 30S:70DODT-CB combination. In addition to that, it has been identified from the results that the organosulfur based polymer PSDODT can be utilised as an alternative to conventional elemental sulfur, and this opens up some new research and development possibilities in the field of Li-sulfur batteries.

Chitosan Film as a Replacement for Conventional Sulphur Dioxide Treatment of White Wines: A 1H NMR Metabolomic Study.

Chitosan-genipin (Ch-Ge) films have been proposed for the replacement of sulfur dioxide (SO2) in white wines preservation to circumvent the adverse health consequences caused by SO2 intake. To assess the effects of different-sized Ch-Ge films (25 and 100 cm2) on wine composition compared to SO2-treated and untreated wines, nuclear magnetic resonance metabolomics was applied. Relative to SO2, 100 cm2 films induced significant changes in the levels of organic acids, sugars, amino acids, 5-hydroxymethylfurfural, among other compounds, while 25 cm2 films appeared to induce only small variations. The observed metabolite variations were proposed to arise from the mitigation of fermentative processes, electrostatic interactions between acids and the positively charged films and the promotion of Maillard and Strecker reactions. Qualitative sensory analysis showed that wines maintained overall appropriate sensory characteristics, with 100 cm2 film treated wines showing slightly higher attributes. Based on these results, the possibility of using Ch-Ge films as a replacement for SO2 treatment is discussed.

Biodiesel feedstock determines exhaust toxicity in 20% biodiesel: 80% mineral diesel blends

To address climate change concerns, and reduce the carbon footprint caused by fossil fuel use, it is likely that blend ratios of renewable biodiesel with commercial mineral diesel fuel will steadily increase, resulting in biodiesel use becoming more widespread. Exhaust toxicity of unblended biodiesels changes depending on feedstock type, however the effect of feedstock on blended fuels is less well known. The aim of this study was to assess the impact of biodiesel feedstock on exhaust toxicity of 20% blended biodiesel fuels (B20). Primary human airway epithelial cells were exposed to exhaust diluted 1/15 with air from an engine running on conventional ultra-low sulfur diesel (ULSD) or 20% blends of soy, canola, waste cooking oil (WCO), tallow, palm or cottonseed biodiesel in diesel. Physico-chemical exhaust properties were compared between fuels and the post-exposure effect of exhaust on cellular viability and media release was assessed 24 h later. Exhaust properties changed significantly between all fuels with cottonseed B20 being the most different to both ULSD and its respective unblended biodiesel. Exposure to palm B20 resulted in significantly decreased cellular viability (96.3 ± 1.7%; p < 0.01) whereas exposure to soy B20 generated the greatest number of changes in mediator release (including IL-6, IL-8 and TNF-α, p < 0.05) when compared to air exposed controls, with palm B20 and tallow B20 closely following. In contrast, canola B20 and WCO B20 were the least toxic with only mediators G-CSF and TNF-α being significantly increased. Therefore, exposure to palm B20, soy B20 and tallow B20 were found to be the most toxic and exposure to canola B20 and WCO B20 the least. The top three most toxic and the bottom three least toxic B20 fuels are consistent with their unblended counterparts, suggesting that feedstock type greatly impacts exhaust toxicity, even when biodiesel only comprises 20% of the fuel.

Construction of mechanically strong and dual network-induced elastomeric materials with self-healing functionality

Imparting contradictory features like mechanical robustness and self-healing capability in an elastomer is pretty tough. In this work, introduction of zinc dimethacrylate (ZDMA) onto macromolecular chains via ring-opening reaction and interaction between epoxy and ZDMA, a mechanically robust and dual network-induced elastomeric material with self-healing functionality was constructed in a commercially available and widely used epoxidized natural rubber (ENR). Self-adjustment of ionic moieties post deformation due to strong ionic interaction in the network along with the interdiffusion characteristics of ENR chains helps to achieve self-healing functionality. With increasing ZDMA loading, both the covalent and ionic networks increases. Surprisingly, ZDMA not only enhances self-healing ability by enhancing ionic interaction with ENR, but also enhances mechanical performance substantially by creating reinforcing effects owing to formation of ionic clusters as evident from the high-resolution transmission electron microscopy images. At 40 phr loading of ZDMA, the tensile strength and modulus at 100% elongation reached ∼14.0 and ∼3.2 MPa respectively, which were much higher than the conventional sulphur vulcanizate ENR. This work provides a facile strategy to develop a mechanically robust and self-healing elastomeric engineered materials using a widely important commercial rubber. • A new kind of mechanically strong and dual networks elastomeric materials with self-healing functionality was developed. • The developed materials showed high tensile strength (∼14.0 MPa) and 100% modulus (∼3.2 MPa). • In-situ developed ionic clusters in the rubber matrix acts as a reinforcement.