Aromatic Content Research Articles

Metal Oxide Nanoparticles Containing Clotrimazole to Suppress Photodegradation of Poly(Vinyl Chloride) Thin Films.

Pol(vinyl chloride) or PVC has functional properties that enable its use in many industrial applications. It suffers from aging, however, in harsh conditions (e.g., elevated temperature or high humidity levels) if oxygen is present. One way to enhance the photostability of PVC is to blend it with additives. Thus, thin films were made by mixing PVC with clotrimazole, and five metal oxide (titanium, copper, cobalt, chromium, and nickel oxides) additives. The metal oxides and clotrimazole were added at concentrations of 0.1 and 0.5% by weight, respectively. The effect of the metal oxide nanoparticles accompanied by clotrimazole on the photodegradation of PVC was then assessed. The results indicated that the additives have a stabilizing effect and protect PVC against photodegradation significantly. The formation of polymeric fragments of small molecular weight containing carbon-carbon double bonds and carbonyl groups was lower in the blends containing metal oxide nanoparticles and clotrimazole than in unblended PVC. Similarly, the decrease in weight was much less for the films blended with additives. Additionally, surface analysis of the irradiated polymeric films showed significantly lower damage in the materials containing additives. The most effective additive in the stabilization of PVC was nickel oxide nanoparticles. The metal oxides are highly alkaline and act as scavengers for the hydrogen chloride produced during the photodegradation of PVC. They additionally act as peroxide decomposers. In contrast, clotrimazole can absorb harmful radiation and act as an ultraviolet absorber due to its heteroatom and aromatic content. Thus, the use of a combination of metal oxide nanoparticles and clotrimazole led to significant improvement in the resistance of PVC toward photodegradation.

Boosting the activity in the direct conversion of CO2/CO mixtures into gasoline using ZnO-ZrO2 catalyst in tandem with HZSM-5 zeolite

The direct production of C5+ hydrocarbons from CO2/CO mixtures with methanol as intermediate is an attractive alternative for the production of gasoline from CO2 and syngas derived from biomass. With this purpose, the performance of CuO-ZnO-ZrO2 (CZZ), In2O3-ZrO2 (IZ) and ZnO-ZrO2 (ZZ) metallic oxides was compared by using them in tandem with a HZSM-5 zeolite. The catalysts were analyzed by means of N2 adsorption-desorption, XRD, XRF, H2-TPR and NH3-TPD. Two series of runs were performed in a packed bed reactor: (i) the methanol synthesis with the metallic oxides as catalysts, at 250–430 °C; 50 bar; CO2/COx, 0–1; H2/COx, 3; space time 6 gcat h molC−1; and (ii) the synthesis of hydrocarbons with the tandem catalysts with a metallic oxide/zeolite mass ratio of 1/1, at 340, 380 and 420 °C; 30 and 50 bar; CO2/COx, 0.5 and 1; H2/COx, 3; space time 12 gcat h molC−1. The results were quantified in terms of yield and selectivity of the product fractions and CO2 and COx (CO2 + CO) conversion. The higher methanol yield attained with the CZZ catalyst for the CO + H2 feed and its mixing with CO2 was faded by the problem of its sintering above 350 °C (minimum temperature required for the extent of methanol conversion to hydrocarbons). The IZ and ZZ catalysts were active, selective to methanol and stable both in the methanol synthesis and when used in IZ/HZSM-5 and ZZ/HZSM-5 tandem catalysts. Excellent results were obtained with the latter, which resulted in a 20.7% yield of C5+ hydrocarbon fraction at 420 °C and 50 bar, with CO2 and COx conversion of 39.7% and 28.4%, respectively. This fraction corresponded to isoparaffinic gasoline, with isoparaffin yield (mainly C5 and C6) surpassing 20% and low concentration of aromatics (0.1%) that led to a Research Octane Number of 91.8. This composition results attractive for its integration into the refineries gasoline pool. Furthermore, the changes of the CO2/COx ratio in the feed barely affected the yield and composition of the gasoline obtained with the ZZ/HZSM-5 catalyst, stating its great versatility.

A Thermo-Catalytic Pyrolysis of Polystyrene Waste Review: A Systematic, Statistical, and Bibliometric Approach.

Global polystyrene (PS) production has been influenced by the lightness and heat resistance this material offers in different applications, such as construction and packaging. However, population growth and the lack of PS recycling lead to a large waste generation, affecting the environment. Pyrolysis has been recognized as an effective recycling method, converting PS waste into valuable products in the chemical industry. The present work addresses a systematic, bibliometric, and statistical analysis of results carried out from 2015 to 2022, making an extensive critique of the most influential operation parameters in the thermo-catalytic pyrolysis of PS and its waste. The systematic study showed that the conversion of PS into a liquid with high aromatic content (84.75% of styrene) can be achieved by pyrolysis. Discussion of PS as fuel is described compared to commercial fuels. In addition, PS favors the production of liquid fuel when subjected to co-pyrolysis with biomass, improving its properties such as viscosity and energy content. A statistical analysis of the data compilation was also discussed, evaluating the influence of temperature, reactor design, and catalysts on product yield.

Nitrate_dependent suberization regulates cadmium uptake and accumulation in maize

In this study, effect of nitrate-dependent suberization in maize root on cadmium (Cd) uptake and accumulation was investigated. Suberization in maize roots was significantly lower in plants grown with a high nitrate supply compared with low nitrate. This decrease was seen in the total amount of suberin, in which the aliphatic suberin amount was significantly decreased, whereas no difference in aromatic suberin content between different N-treatments. RNA-sequencing showed that suberin biosynthesis genes were upregulated in low nitrate treatment, which correlated well with the increased suberin content. Bioimaging and xylem sap analysis showed that reduced exodermal and endodermal suberization in roots of plants grown under high nitrate promoted radial Cd transport along the crown root. The enhanced suberization in crown roots of plants grown in low nitrate restricted the radial transport of Cd from epidermis to cortex via decreased accessibility to Cd related transporters at the plasmalemma. Also, under low nitrate supply, the Cd transport gene ZmNramp5 was upregulated in the crown root, which may enhance Cd uptake by root tip where exodermis and endodermis were not fully suberized. These results suggest that high nitrate supply enhances Cd uptake and radial transport in maize roots by reducing exodermal and endodermal suberization.

Science‐guided data analytics for selecting ionic liquid solvents for aromatic extraction

AbstractIonic liquids (ILs) are promising solvents for the aromatic extraction process. An attractive characteristic is the existence of hundreds of ILs that exhibit different properties. To identify key properties of IL solvents for an energy‐optimum aromatic extraction, we use process simulation to generate the process datasets for multivariate data analytics with partial least squares, and use science‐guided fundamentals to develop an IL heat load variable (HLV). We consider 16 well‐studied ILs and correlate process steam duty and process variables affecting equipment size to the HLV for ethylene cracker feeds of low aromatic content. For such feeds in an IL aromatic extraction process, 11 of 16 ILs show energy advantage compared with sulfolane solvent with the lowest energy IL process requiring 57% of total energy required for an equivalent sulfolane process. Our results facilitate the IL solvent selection for pilot tests and subsequent commercialization of an IL aromatic extraction process.

Accumulation of Toxic Arsenic by Cherry Radish Tuber (Raphanus sativus var. sativus Pers.) and Its Physiological, Metabolic and Anatomical Stress Responses

In a pot experiment, cherry radish (Raphanus sativus var. sativus Pers. 'Viola') was cultivated under two levels of As soil contamination-20 and 100 mg/kg. The increasing As content in tubers with increasing soil contamination led to changes in free amino acids (AAs) and phytohormone metabolism and antioxidative metabolites. Changes were mainly observed under conditions of high As contamination (As100). The content of indole-3-acetic acid in tubers varied under different levels of As stress, but As100 contamination led to an increase in its bacterial precursor indole-3-acetamide. A decrease in cis-zeatin-9-riboside-5'-monophosphate content and an increase in jasmonic acid content were found in this treatment. The free AA content in tubers was also reduced. The main free AAs were determined to be transport AAs (glutamate-Glu, aspartate, glutamine-Gln, asparagine) with the main portion being Gln. The Glu/Gln ratio-a significant indicator of primary N assimilation in plants-decreased under the As100 treatment condition. A decrease in antioxidative metabolite content-namely that of ascorbic acid and anthocyanins-was observed in this experiment. A decline in anthocyanin content is related to a decrease in aromatic AA content which is crucial for secondary metabolite production. The changes in tubers caused by As contamination were reflected in anatomical changes in the radish tubers and roots.

Study of the long-finned pilot whale (Globicephala melas) bile content - An indicator of ocean health

Globicephala melas has been harvested in the Faroe Islands for centuries. Given the distances travelled by this species, tissue/body fluid samples represent unique matrices to be considered as an integration of environmental condition and pollution status of their prey. For the first time, bile samples were analysed for presence of polycyclic aromatic hydrocarbon (PAH) metabolites and protein content. Concentrations of 2- and 3-ring PAH metabolites ranged from 11 to 25 μg mL−1 pyrene fluorescence equivalents. In total, 658 proteins were identified and 61,5 % were common amongst all individuals. Identified proteins were integrated into in silico software and determined that the top predicted disease and functions were neurological diseases, inflammation, and immunological disorders. The metabolism of reactive oxygen species (ROS) was predicted to be dysregulated, which can have consequences to both the protection against ROS produced during dives and contaminant exposures. The obtained data is valuable for understanding metabolism and physiology of G. melas.

CRISPR/Cas9-mediated homology donor repair base editing confers glyphosate resistance to rice (Oryza sativa L.).

Globally, CRISPR-Cas9-based genome editing has ushered in a novel era of crop advancements. Weeds pose serious a threat to rice crop productivity. Among the numerous herbicides, glyphosate [N-(phosphonomethyl)-glycine] has been employed as a post-emergent, broad-spectrum herbicide that represses the shikimate pathway via inhibition of EPSPS (5'-enolpyruvylshikimate-3-phosphate synthase) enzyme in chloroplasts. Here, we describe the development of glyphosate-resistant rice lines by site-specific amino acid substitutions (G172A, T173I, and P177S: GATIPS-mOsEPSPS) and modification of phosphoenolpyruvate-binding site in the native OsEPSPS gene employing fragment knockout and knock-in of homology donor repair (HDR) template harboring desired mutations through CRISPR-Cas9-based genome editing. The indigenously designed two-sgRNA OsEPSPS-NICTK-1_pCRISPR-Cas9 construct harboring rice codon-optimized SpCas9 along with OsEPSPS-HDR template was transformed into rice. Stable homozygous T2 edited rice lines revealed significantly high degree of glyphosate-resistance both in vitro (4 mM/L) and field conditions (6 ml/L; Roundup Ready) in contrast to wild type (WT). Edited T2 rice lines (ER1-6) with enhanced glyphosate resistance revealed lower levels of endogenous shikimate (14.5-fold) in contrast to treated WT but quite similar to WT. ER1-6 lines exhibited increased aromatic amino acid contents (Phe, two-fold; Trp, 2.5-fold; and Tyr, two-fold) than WT. Interestingly, glyphosate-resistant Cas9-free EL1-6 rice lines displayed a significant increment in grain yield (20%-22%) in comparison to WT. Together, results highlighted that the efficacy of GATIPS mutations in OsEPSPS has tremendously contributed in glyphosate resistance (foliar spray of 6 ml/L), enhanced aromatic amino acids, and improved grain yields in rice. These results ensure a novel strategy for weed management without yield penalties, with a higher probability of commercial release.

Comprehensive identification of key compounds in different quality grades of soy sauce-aroma type baijiu by HS-SPME-GC-MS coupled with electronic nose.

In the production of soy sauce-aroma type baijiu (SSAB), the quality of base liquor significantly affects the finished liquor's quality. Moreover, low-quality liquor may cause health problems. The different quality grades of base liquor were analyzed to investigate the relationship between the quality and the key compounds in SSAB. In this study, samples were evaluated by the sensory and further analyzed by headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) coupled with electronic nose (E-nose). First, by sensory evaluation, the sauce, floral and fruity, fermented aromas and taste indicators (softness, fullness, harmony, purity and persistence) were positively correlated with the quality grade of the base liquor. The E-nose could distinguish the different quality grades of base liquor well. Second, differential compounds were identified via untargeted metabolome based on the HS-SPME-GC-MS. 16 common differential compounds were shared in the base liquor from different fermentation rounds, including 11 esters, 1 alcohol, 2 aldehydes and 2 ketones. It was found that the higher the quality grade of the base liquor, the richer the content of aromatics, alcohols, aldehydes and ketones. The principal component analysis (PCA) biplots of the differential compounds in the different quality grades of base liquor indicated that the superior-grade base liquor has a strong fruity aroma. By correlation analysis of the differential compounds and sensors responses of E-nose, furfuryl ethyl ether, butanoic acid ethyl ester, isopentyl hexanoate, nonanoic acid ethyl ester and 3-methyl-1-butanol had a significant effect on the response intensity of E-nose sensors. In the present study, the key differential compounds between the different quality grades of base liquor were identified, and the sensory differences between the base liquor were digitized.

Machine Learning Models for Predicting Asphaltene Stability Based on Saturates-Aromatics-Resins-Asphaltenes

Summary Asphaltene precipitation is one of the challenging flow assurance problems as it can cause permeability impairment and pipeline blockages by depositing on the surface of well tubing, flowlines, and heat exchangers. The cost of remediating an unexpected asphaltene problem is expensive and time-consuming wherever offshore or on land. Thus, the provision of asphaltene precipitation is vital and an effective approach is stability screening for monitoring asphaltene precipitation problems. In this study, asphaltene stability performance in crude oil was evaluated using six machine learning (ML) techniques, namely decision tree (DT), Naïve Bayes (NB), support vector machine (SVM), artificial neural networks (ANN), random forest (RF), and k-nearest neighbor (KNN). A large stability data containing 186 crude oil samples of known stability were used to design the classification models for predicting asphaltene stability. The inputs to the models were the content of saturates, aromatics, resins, and asphaltenes (SARA); and the output was stability. The classification results showed that the best classification model is the KNN classifier, and it has an accuracy of 82%, area under the curve (AUC) of 83%, precision of 75%, and f1-score of 83%. Also, three empirical correlations with high accuracy including stability index (SI), stability crossplot (SCP), and asphaltene stability predicting model (ANJIS) were utilized comparatively with the ML models to evaluate asphaltene stability. Results revealed that the KNN classifier has superior performance in this work with an accuracy of 80%, a precision of 82%, and an f1-score of 79%. Results of this study showed that ML is effective for asphaltene stability, providing potential in asphaltene management to reduce asphaltene deposition risk in production.

Better Performance in C2-Conversion to Aromatics by Optimized Feed and Catalysts

We identify favorable parameters for the formation of aromatics from ethanol-based feeds over ZSM-5. An ethanol partial pressure of 0.3 bar, a reaction temperature of ∼700 K, a low weight hourly space velocity (WHSV), and a high Brønsted acid site density increase the content of aromatics, in the latter case, on the expense of lifetime. The aromatic fraction composition changes with the WHSV and nSi/nAl ratio. Water cofeed increases the content of aromatics in the C2:H2O stoichiometry of 1:0.5 (equals diethyl ether as feed) but decreases it if this is exceeded. Diethyl ether and ethylene lead to more aromatics than ethanol feed. The lifetime until deactivation increases in the order ethanol < diethyl ether < ethylene. This points at different reaction and/or deactivation mechanisms in converting the three feeds. Thus, a water-poor feed effectively improves the catalyst lifetime and productivity in the ethanol conversion to aromatics.

Effects of molecular weight fraction on antioxidation capacity of rice protein hydrolysates

Rice protein was used as a starting material to provide rice protein hydrolysates (RPH) through enzyme-assisted extraction. RPH was further fractionated using ultrafiltration membrane (UF) and classified by molecular weight (MW; MW < 1 kDa, MW 1–10 kDa, and MW > 10 kDa). Peptides with MW < 1 kDa possessed superior antioxidant properties (p < 0.05). Therefore, UF demonstrated great efficacy in selectively separating antioxidant peptides. A Pearson correlation analysis revealed that the total phenolic concentration was correlated with oxygen radical absorbance capacity (ORAC; r = 0.999, p < 0.05). Amino acid contents had negative correlations with the scavenging activity (specifically, IC50) of 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radicals (r = − 0.986 to − 1.000). Reducing power was related to aromatic amino acid contents (r = 0.997, p < 0.05). In this study, enzymatic hydrolysis was discovered to be an effective method of extracting and isolating natural antioxidant proteins from broken rice, thus preserving the nutritional quality of rice and making those proteins more accessible in future applications.

Terrigenous dissolved organic matter input and nutrient-light-limited conditions on the winter microbial food web of the Beagle Channel

The viral shunt and microbial loop are trophic pathways in the microbial food web, recognized as major drivers of carbon and nutrient cycles in the sea. The Beagle Channel, located at the southernmost extreme of South America, is a subantarctic marine environment influenced by terrestrial runoff and glacial meltwater with high temporal and spatial variability. There is a knowledge gap on the trophic pathways and the microbial food web in the eastern part of the Channel. We herein present for the first time a comprehensive and spatially wide study of the effects of physicochemical and bio-optical parameters on the microbial food web along the Eastern Beagle Channel. The study took place under winter hydrographic conditions, featuring weak vertical stratification of the water column and low chlorophyll a concentrations (0.13 ± 0.07 mg m−3). Biogeochemical gradients were notable between the inner and outer (easternmost) sectors of the Channel, separated by a shallow sill at Mackinlay Strait. As a chemical water mass tracer, the presence of the highest concentrations in bottom waters of NO3 + NO2 in the inner channel and the difference in the T-S diagram indicate the Subantarctic Pacific origin of this water mass. Structural equation models showed that the specific UV absorbance of water (SUVA254, a proxy for the aromatic carbon content) and NO3 + NO2 were the main parameters affecting the microbial food web in surface/subsurface waters suggesting that prokaryotes biomass was partially supported by allochthonous dissolved organic matter (DOM) derived from river discharges. Our results show a major role of the viral shunt in surface/subsurface waters retaining nutrients in the basal levels of the food web. We suggest that the viral shunt in surface/subsurface waters and the water residence time west of Mackinlay Strait allows infected cells and viral lysis products to reach bottom waters propelling the production of recalcitrant and labile DOM there.

Effect of variable pressure-assisted immersion process using (−)-epicatechin on the color, flavor, and polycyclic aromatic hydrocarbons content in roasted beef meat

Polycyclic aromatic hydrocarbons (PAHs) are more easily formed in beef meat than other meats. A previous study confirmed the inhibitory effect of (−)-epicatechin on PAHs in a fat model system. However, (−)-epicatechin solution demonstrates colloidal properties at high concentrations. Hence a variable pressure immersion method was applied to infuse (−)-epicatechin in beef cubes. The fixed variable pressure-assisted immersion process using (−)-epicatechin that ranged from 0.2 mM/L to 5.0 mM/L was found to influence color, flavor, and PAHs dose-dependently. The 0.2 mM/L (−)-epicatechin treatment stabilized color properties, reduced PAHs content, and promoted the formation of volatiles and free amino acids. However, the use of more than 1.0 mM/L (−)-epicatechin, gradually decreased the values of brightness (L*) and yellow to blue color (b*), volatiles and free amino acids content, and reduced the inhibitory effect on PAHs. Therefore, the variable pressure-assisted immersion process of meat in 0.2 mM/L (−)-epicatechin can inhibit PAHs formation without compromising flavor properties of roasted beef.

Unveiling the Role of Dissolved Organic Matter on the Hg Phytoavailability in Biochar-Amended Soils.

Biochar can effectively reduce the phytoavailability of mercury (Hg) in soil, but the mechanisms are not fully understood. In this study, the dynamic changes in Hg content adsorbed by the biochar (BC-Hg), Hg phytoavailability in the soil (P-Hg), and soil dissolved organic matter (DOM) characteristics were determined over a 60-day treatment period. Biochar obtained at 300 °C, 500 °C and 700 °C reduced the P-Hg concentration assessed by MgCl2 extraction by 9.4%, 23.5% and 32.7%, respectively. However, biochar showed a very limited adsorption on Hg, with the maximum BC-Hg content only accounting for 1.1% of the total amount. High-resolution scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDS) results showed that the proportion of Hg atoms in biochar after 60 d was barely detectable. Biochar treatment can shift soil DOM toward higher aromatic content and molecular weight. Additionally, the addition of high-temperature biochar increased more humus-like components, but low-temperature biochar increased more protein-like components. Correlation analysis and partial least squares path modeling (PLS-PM) showed that biochar promoted humus-like fractions formation to reduce the Hg phytoavailability. This research has deepened the understanding of the mechanisms by which biochar stabilizes Hg in agricultural soils.

Production of light aromatics by co-pyrolysis of lignite and plastics: Effect of metal loaded HZSM-5

Plastic products containing high levels of hydrogen can act as hydrogen donors during coal pyrolysis to promote the production of light tars such as alkanes, olefins, and aromatic hydrocarbons. In this study, metal loaded HZSM-5 was applied to enhance the yields of light aromatics such as benzene, toluene, ethylbenzene, xylene, naphthalene and methylnaphthalene (BTEXNM) in the catalytic co-pyrolysis of lignite and HDPE/waste plastic. The effect of HZSM-5 catalysts on the preparation of BTEXNM under different metal loadings (Cu, Fe, Co, Mo, Ga), different loadings (1 wt%, 3 wt%, 5 wt%, 7 wt%) and bimetallic (Ga, Mo) loadings was studied by using Py-GC/MS. The results showed that the highest content of light aromatics was achieved at a pyrolysis temperature of 600 °C and a lignite to plastic mix ratio of 3:1. After metal loaded HZSM-5, Ga and Mo increased the content of aromatic products, with 3 wt%Ga being the most effective. In the Ga and Mo bimetallic modification experiments, the 1 wt%Mo2wt%Ga/HZSM-5 combination was the most effective, with a significant increase in the content of monocyclic aromatic hydrocarbons such as benzene, toluene and xylene, and a relative decrease in the content of polycyclic aromatic hydrocarbons such as naphthalene and methylnaphthalene.

Base-acid relay catalytic upgrading of coal pyrolysis volatiles over CaO and HZSM-5 catalysts

The relay catalytic upgrading of coal pyrolysis volatiles employing different layouts of basic CaO and acidic HZSM-5 zeolite was proposed to improve the tar quality as well as alleviate catalyst deactivation. The synergistic effect is found in relay catalytic upgrading of coal pyrolysis volatiles over dual CaO and HZSM-5 catalysts system. The relay CaO-HZSM-5 layout is better compared to layouts of relay HZSM-5-CaO, mixed CaO/HZSM-5, and their independent employments. The relay CaO-HZSM-5 layout ensures the highest light fraction in tar with 70.1 % and the minimized carbon deposition over HZSM-5 while remaining a relatively high tar yield (7.8 wt %). Meanwhile, the contents of aromatics and phenols in tar increase by 221 % and 164 % compared with the blank test (without catalyst), respectively. In this scenario, CaO promotes the cracking of large molecules in tar to form more olefins and small molecules firstly, which subsequently diffuses into micropores of HZSM-5 zeolite to produce more aromatics by dehydrocyclization. In addition, the roles of pre-cracking and pre-deoxidation of volatiles over CaO reduce the possibility of the polycondensation reactions of large molecules over acidity sites of HZSM-5 zeolite, thus lowering the carbon deposition over zeolite. These findings suggest that the base-acid relay catalytic upgrading of volatiles during coal pyrolysis will be a promising strategy to increase the tar quality and slow down catalyst deactivation.

Highly Dispersed Pt Catalysts on Hierarchically Mesoporous Organosilica@Silica Nanoparticles with a Core–Shell Structure for Polycyclic Aromatic Hydrogenation

Hydrogenation of naphthalene can effectively reduce the content of aromatics in oil and generate high-value products. A series of Pt-based aluminum-modified core-shell-structured hierarchically periodic mesoporous organosilica@mesoporous silica nanoparticles (Pt/Al-x-PMOs@MSNs) were successfully synthesized and tested for the hydrogenation properties, with preferable mass transfer of macromolecular reactants in the pores and increasing the total acidity of the catalysts. Moreover, the physicochemical properties of the core-shell-structured Pt-based catalysts were systematically analyzed using various characterization techniques. At 300 °C, the naphthalene conversion on the Pt/Al-10-PMOs@MSNs catalyst reached up to 100%, the selectivity of trans-decalin reached 83.9%, and the rate constants (k1, k2) and TOF were 13.2 × 10-6 mol·g-1·s-1, 1.7 × 10-7 mol·g-1·s-1, and 218.8 h-1, respectively. In the presence of sulfur, the naphthalene hydrogenation over the Pt/Al-10-PMOs@MSN catalyst first decreased to around 40% and then recovered to the original level, which originated from the synergistic effect of the texture and chemical properties over the Pt/Al-10-PMOs@MSNs with an excellent performance.

Synthesis and characterization of poly(1,2,3‐triazole)s with inherent high sulfur content for optical applications

AbstractThe synthesis of solution‐processable sulfur‐containing polytriazoles for optoelectronic applications is a relatively less explored domain in polymer research. The synthesis of novel bifunctional (DA) and trifunctional (TA) azido‐monomers with inherent high sulfur content and of organo‐soluble high refractive index poly(1,2,3‐triazole)s using the azido‐monomers via Cu(I) assisted click polymerization reactions are reported in this work. The azido‐monomers were synthesized by the conversion of previously reported amine‐functionalized compounds to azides using azidotrimethylsilane in a polar aprotic solvent. Dialkyne monomers were also synthesized and reacted with the azides to prepare a series of five linear and two hyperbranched poly(1,2,3‐triazole)s. Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, differential scanning calorimetry and thermogravimetric analysis were used to characterize the synthesized polymers. It was also demonstrated that the use of the trifunctional azide in optimized conditions resulted in increased solubility of an otherwise insoluble linear poly(1,2,3‐triazole). The optical characterization of the polymers was carried out on thin polymer films with thickness in the nanometer range, which were successfully prepared by spin‐coating on silicon wafers. It was found that the increase in the sulfur and aromatic content in the polymer backbone successfully increased the refractive index of the polymers up to 1.743 at 589 nm.

Production of transportation fuels via hydrotreating of scrap tires pyrolysis oil

The hydrotreating of scrap tires pyrolysis oil over commercial Ni-Mo/Al2O3 catalyst was researched for the best processing scheme allowing the production of high-quality alternative transportation fuels components of gasoline, jet, diesel, and marine fuel. Despite the initial high content of olefins, aromatics, sulfur, and nitrogen in pyrolysis oil, fuel components obtained by redistillation after the hydrotreating at 360 °C and 10 MPa met the majority of standard fuel specifications. Although the octane number of the naphtha fraction was lower, this fraction can be used as acomponent of the gasoline pool directly or after the catalytic reforming. Kerosene fraction can be utilized as jet fuel after the additional mild hydrotreatment or blending with hydroprocessed esters and fatty acids (HEFA) to decrease aromatics content. Diesel fraction can be blended with hydrotreated vegetable oils (HVO) to fulfill the density and cetane index specification. The bottom residue can be utilized as a low-sulfur fuel oil component in marine transportation.