Search Results (7)

Medium-temperature pitch was obtained by vacuum distillation of coal tar from the Qarmet coke chemical production. To determine the composition of the organic constituent of the Qarmet coal tar, the component composition was analyzed via gas–liquid chromatography (GLC) methods. The analysis of the component composition of the organic component of coal tar showed that the content of naphthalene and its derivatives is 37.57%, acenaphthene—2.10%, dibenzofurane—3.60%, fluorene—4.63%, phenanthrene—8.63%, anthracene—2.29%, fluoranthene—4.56%, and pyrene—2.84%. It was found that in the obtained pitch sample, indicators such as the content of insoluble in toluene (41.86%), the softening temperature (85–91 °C), and the yield of volatile substances (1.5%) are more consistent with the standards for electrode pitch grade “V”. The composition of fractions in baking soda, soluble in toluene and quinoline, has been established. In the fractions of pitch soluble in toluene, 11 components were identified, the main of which re fluoranthene (11.71%), pyrene (10.13%), phenanthrene (7.31%), and benzopyrene (4.84%). Thus, based on the analyses carried out, it was found that the Qarmet resin is suitable for obtaining a V-grade electrode pitch, which can be used in the aluminum industry. Full article

The quinoline-insoluble (QI) matter in coal tar and coal tar pitch is an important factor affecting the properties of subsequent carbon materials. In this paper, catalytic polycondensation was used to remove QI from heavy coal tar, and meso-carbon microbeads could be formed during the purification process. The results showed that AlCl₃ had superior catalytic performance to CuCl₂, and the content of QI and heavy components, including pitch, in the coal tar was lower after AlCl₃ catalytic polycondensation. Under the condition of catalytic polycondensation (AlCl₃ 0.9 g, temperature 200 °C, and time 9 h), AlCl₃ could reduce the QI content in heavy coal tar. The formed small particles could be filtered and removed, and good carbon materials could be obtained under the condition of catalytic polycondensation (AlCl₃ 0.9 g, temperature 260 °C, and time 3 h). Full article

This work evaluates the potential for obtaining graphitizable precursors from domestically available coal as a possible solution to the declining availability of high-quality precursors and projected rapid growth driven by demand for synthetic graphite in the US. The graphitizability of a coal-derived synthetic pitch (Synpitch) obtained by a novel solvent extraction process is compared with a commercially available petroleum pitch. The process outlined in this paper offers the advantages of lower temperature, pressure, and hydrogen addition requirement. An upgraded (higher H/C) aromatic pitch with low quinoline insoluble (QI) and ash content is obtained. The distinctions between the pitches have been characterized using Fourier transform infrared spectroscopy, nuclear magnetic resonance, and thermogravimetric analysis/differential scanning calorimetry. The pitches have been graphitized at 2500 °C and characterized by X-ray diffraction and transmission electron microscopy for graphitic quality assessment. The Synpitch showed larger crystallites (by over 50%) and markedly better nanostructure compared to the commercial pitch used in this study. The structural differences between the pitches are highlighted here to explain the significantly better graphitic quality of the Synpitch. Full article

The naturally occurring neocryptolepine (5-Methylindolo [2,3-b]quinoline) and its analogs exhibited prominent anticancer and antimalarial activity. However, the main problem of this class of compounds is their poor aqueous solubility, hampering their bioavailability and preventing their clinical development. To overcome the problem of insolubility and to improve the physicochemical and the pharmacological properties of 5-Methylindolo [2,3-b]quinoline compounds, this work was designed to encapsulate such efficient medical compounds into mesoporous silica oxide nanoemulsion (SiO₂NPs). Thus, in this study, SiO₂NPs was loaded with three different concentrations (0.2 g, 0.3, and 0.6 g) of 7b (denoted as NPA). The findings illustrated that the nanoparticles were formed with a spherical shape and exhibited small size (less than 500 nm) using a high concentration of the synthesized chemical compound (NPA, 0.6 g) and good stabilization against agglomeration (more than −30 mv). In addition, NPA-loaded SiO₂NPs had no phase separation as observed by our naked eyes even after 30 days. The findings also revealed that the fabricated SiO₂NPs could sustain the release of NPA at two different pH levels, 4.5 and 7.4. Additionally, the cell viability of the produced nanoemulsion system loaded with different concentrations of NPA was greater than SiO₂NPs without loading, affirming that NPA had a positive impact on increasing the safety and cell viability of the whole nanoemulsion. Based on these obtained promising data, it can be considered that the prepared NPA-loaded SiO₂NPs seem to have the potential for use as an effective anticancer drug nanosystem. Full article

Various fractionalized solvents with different paraffinicities were adopted to maximize the efficiency of the quinoline insoluble (QI) extraction process for coal tar pitch. In addition, highly pressurized conditions combined with raised temperature (4 bar at 300 °C) were used to accelerate the reaction kinetics of the extraction process. The QI content of purified coal tar pitch was analyzed to be 0.1% at a process yield of up to 72% as a solvent with a K-factor of 10 and above was used. Purified coal tar pitch was then processed to form anisotropic coke using a lab-scale tube bombe reactor. The texture observed under a polarized light microscope showed an anisotropic flow domain, a unique morphological feature of needle coke. The additives and reaction conditions used in this study for QI extraction for coal tar pitch were found to be effective and feasible as preliminary processing in needle coke production. Full article

Parkinson’s disease (PD) is a common neurodegenerative disorder characterized by the loss of dopaminergic (DAergic) neurons and the presence of α-synuclein-containing Lewy bodies. The unstructured α-synuclein forms insoluble fibrils and aggregates that result in increased reactive oxygen species (ROS) and cellular toxicity in PD. Neuroinflammation engaged by microglia actively contributes to the pathogenesis of PD. In this study, we showed that VB-037 (a quinoline compound), glycyrrhetic acid (a pentacyclic triterpenoid), Glycyrrhiza inflata (G. inflata, a Chinese herbal medicine), and Shaoyao Gancao Tang (SG-Tang, a formulated Chinese medicine) suppressed the nitric oxide (NO) production and interleukin (IL)-1β maturation in α-synuclein-stimulated BV-2 cells. Mouse inflammation antibody array further revealed increased IL-1α, IL-1β, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) expression in α-synuclein-inflamed BV-2 cells and compound pretreatment effectively reduced the expression and release of these pro-inflammatory mediators. The test compounds and herbal medicines further reduced α-synuclein aggregation and associated oxidative stress, and protected cells against α-synuclein-induced neurotoxicity by downregulating NLR family pyrin domain containing 1 (NLRP1) and 3 (NLRP3), caspase 1, IL-1β, IL-6, and associated nuclear factor (NF)-κB inhibitor alpha (IκBα)/NF-κB P65 subunit (P65), c-Jun N-terminal kinase (JNK)/proto-oncogene c-Jun (JUN), mitogen-activated protein kinase 14 (P38)/signal transducer and activator of transcription 1 (STAT1) and Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathways in dopaminergic neurons derived from α-synuclein-expressing SH-SY5Y cells. Our findings indicate the potential of VB-037, glycyrrhetic acid, G. inflata, and SG-Tang through mitigating α-synuclein-stimulated neuroinflammation in PD, as new drug candidates for PD treatment. Full article

Carbon/carbon (C/C) composites are conventionally manufactured by liquid-phase impregnation (LPI), in which the binder pitches and phenolic resins are impregnated into the composites, and by chemical vapor infiltration (CVI). However, CVI has certain limitations in that expensive gases, such as methane and propane, are used and a long reaction time is required. Therefore, LPI is more widely used, as it employs economical pitches. In this study, the effects of one-step preparation on mechanical properties of C/C composites impregnated with mesophase binder pitches and phenolic resins have been investigated. The C/C composites containing four types of 20 wt.% mesophase binder pitches had differences in softening point (SP) and quinoline insoluble (QI) contents. After conducting trials on mesophase formation using different heat treatment temperatures and times, the best density and mechanical properties of the C/C composites were achieved using the mesophase binder pitches with 170 °C SP. However, when SP 200 °C was used, the density of the C/C composites was not further improved. This is because the binder pitches were not properly impregnated into the composites due to the high viscosity and QI of the binder pitches. Furthermore, the C/C composites fabricated with 20 wt.% pitch 2 exhibited the highest mechanical properties. Full article