查看更多>>摘要：? 2021 The Korean Society of Industrial and Engineering ChemistryTo explore a new family of organic ionic materials, a series of α,ω-bis[N,N′-(4-alkylpyridinium)]alkane salts combined with iodide (I?), tetrafluoroborate (BF4?), and bis(trifluoromethanesulfonyl)imide (Tf2N?) anions and alkylene bridges of different lengths are synthesized. From 1H NMR chemical shift changes, the proton acidity of at the bis-pyridinium cations can be estimated for different anions. All the synthesized I? and BF4? salts have one or multiple solid–solid phase transitions, which are typical features of plastic and liquid crystals. The I? or BF4? salts with large values (>90 J mol?1 K?1) of total entropy changes in solid–solid phase transitions (Σ(ΔSss)) would have a very soft crystalline phase. Combined with polarized microscope images and wide-angle X-ray diffraction spectra, 1,2-bis[N,N′-(4-n-dodecylpyridinium)]ethane 2BF4– may be a true plastic crystal at temperatures above 70 °C. The thermal properties of the bis-pyridinium Tf2N? salts are quite different; they show only a melting transition and are thermally more stable than those of I? and BF4?. The electrochemical window of the bis-pyridinium BF4– and Tf2N? salts is stable up to 4.3 V (vs. Li/Li+).
查看更多>>摘要：? 2021Metal organic framework (MOF)-derived nanocatalysts on various nanostructured supports are generally efficient heterogeneous catalysts employable for organic transformations. Herein, nickel Prussian blue (PB) nanoparticles were deployed to form NiFe2O4 nanocatalysts supported on 2D molybdenum disulfide (MoS2) through a facile heat treatment. NiFe2O4 nanocatalysts could be uniformly dispersed on the high-specific-area MoS2 surface, representing a highly efficient, inexpensive, and magnetically recoverable nanocomposite catalyst. The semiconductor property of MoS2 ensures a high electric conductivity, thus enhancing electron transfer between the reductant and the reactant. Furthermore, the strong magnetic characteristics enable its convenient separation from the reaction mixture. NiFe2O4 nanoparticles on MoS2-supported produces multiple electron transfer pathways and overcomes known drawbacks of catalytic methods that use metals alone, endowing long-term cycle stability. Overall, MoS2/NiFe2O4 exhibited an excellent catalytic activity and high yields in the reduction of nitrobenzene in water, maintained even after five cycles.
查看更多>>摘要：? 2021 The Korean Society of Industrial and Engineering ChemistryPhosphoric acid (PA)-doped membranes are promising electrolytes for high-temperature proton exchange membrane fuel cells (HT-PEMFCs). However, long-term durability issues have been an obstacle to their commercialization. Herein, we report a series of poly(phenylene oxide) (PPO)-based crosslinked membranes containing quaternary ammonium (QA) groups and exhibiting enhanced physicochemical stability and PA retention via ion-pair interactions between QA and PA. The degree of crosslinking in PPO by diamine crosslinker was controlled at 20, 30, and 40. The membranes were also crosslinked (degree = 20) using diamine crosslinkers with variable alkyl chain length (ethyl, butyl, and hexyl). All membranes exhibited sufficient thermal stability (5% weight loss temperatures (TD5%) = ～230 °C) and oxidative stability (～85% in the Fenton test). The PA uptake of the resulting membranes was controlled between 110 and 154% depending on their crosslinked structures. The membrane with the lowest degree of crosslinking (20) and shortest crosslinker exhibited the highest PA uptake and highest anhydrous proton conductivity (0.043 S/cm at 150 °C) in doped state. The proton conductivity was found to be significantly influenced by the PA uptake and crosslinked membrane structures. The highest PA retention of 89% was exhibited by the PA-doped membrane with the highest degree of crosslinking (40).
查看更多>>摘要：? 2021 The Korean Society of Industrial and Engineering ChemistryModified CaCO3@SMA nanoparticles obtained by coordination reaction between poly(styrene-co-maleic anhydride) (SMA) and calcium carbonate (CaCO3) nanoparticles were adopted as additive to prepare polyvinylidene fluoride (PVDF) flat membrane via thermally induced phase separation (TIPS) method with dioctyl phthalate (DOP) and dibutyl phthalate (DBP) as mixed diluent. The CaCO3 nanoparticles modified by SMA effectively reduced the adverse agglomeration of nanoparticles and made the additive disperse evenly in PVDF matrix. The presence of modified CaCO3@SMA changed the membrane morphology from dispersed spherulites with large pores to fuzzy dendrite structures with uniform pore sizes. The membrane pore sizes, pore size distribution and tensile strength were significantly improved compared to both virgin membranes and those containing unmodified CaCO3 nanoparticles. After the CaCO3 was pickled, the porosity and the connectivity between membrane pores were greatly enhanced, resulting in a significant increase in pure water flux. At the same time, the amphiphilic SMA fixed in and on the membrane surface improved the hydrophilic and anti-fouling properties demonstrated in a three-cycle test. The present study provided a potential TIPS method for the fabrication of PVDF membrane combined with a simple strategy of modified inorganic particle additive.
查看更多>>摘要：? 2021 The Korean Society of Industrial and Engineering ChemistrySolvent deasphalting (SDA) is a heavy oil upgrading process that selectively extracts deasphalted oil (DAO) and rejects asphaltenes. In this study, a quantitative analysis was conducted to predict DAO yields in the SDA process using relative energy difference (RED); the RED was calculated from Hansen solubility parameters (HSPs) of the feedstock and extraction solvent along with the extraction conditions, such as temperature and solvent-to-oil ratio (SOR). SDA extraction experiments were performed in a continuous bench-scale unit using vacuum residue (VR) and a mixture of bunker C fuel oil (BC) and VR as feedstocks. The HSPs of saturate, aromatic, resin, and asphaltene fractions derived from the VR and BC were measured using solubility tests, wherein the fractions were dissolved in 37 different solvents. Finally, simple and accurate correlations between the DAO yield and corresponding modified RED were acquired and used to explain the effects of temperature and SOR on the DAO yield.
查看更多>>摘要：? 2021 The Korean Society of Industrial and Engineering ChemistryHigh-throughput and efficient identification of drugs in a complex mixture is required in many pharmaceutical industries and drug testing laboratories. The present study aims to utilize an efficient pooling strategy for the preparation of high-resolution tandem mass spectrometry (HR-MS/MS) library of drugs with different therapeutic properties. Compounds were classified into four classes of low, medium–low, medium–high and high log P values and were pooled into five pools (100 drugs pool). Compounds with isobaric and close log p values were placed in separate groups to overcome the co-elution problem. Liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) was utilized to generate a high-resolution tandem mass spectrometry (MS/MS) spectral library in both positive and negative electrospray ionization modes of 491 drugs. Spectra were collected by LC-MS/MS analysis using system automated collision energy i.e. of 25–60 eV and four predetermined collision energies (10, 20, 30 and 40 eV) for each compound using schedule precursor list of [M + H]+ and [M + Na]+ ions. To validate the applicability of the library, serum samples spiked at three concentrations close to bioavailability (0.308 ng/mL, 3.08 ng/mL and 30.08 ng/mL) of drugs and were analyzed by LC-QTOF-MS/MS. The HRMS library search successfully identified all compounds present in the spiked serum samples based on exact masses of precursor ions, MS/MS data, and retention time etc. The accurate mass LC-QTOF-MS based tandem mass spectral libraries represent a useful tool for the identification of drugs in clinical samples, for pharmacological and forensic screening applications etc.
查看更多>>摘要：? 2021 The Korean Society of Industrial and Engineering ChemistryIn this paper, distillers’ grains biochar (DGBC) was facilely gained by processing the distillers’ grains produced in Chinese Baijiu brewing, and the DGBC was used to modify BiOCl. The prepared DGBC/BiOCl composite photocatalysts show elevated visible light-driven catalytic performance. X-ray diffraction (XRD) and scanning electron microscope (SEM) suggest the presence of DGBC affects the crystal growth and microscopic morphology of BiOCl. The low-temperature electron paramagnetic resonance (EPR) test affirms more oxygen vacancies (OVs) exist in the DGBC/BiOCl composite photocatalysts. The 0.75-DGBC/BOC photocatalyst holds the highest efficiency for removal of rhodamine B (RhB), tetracycline (TC) and Cr (VI) compared with BiOCl, commercial TiO2 (P25) and other DGBC/BiOCl composites. Given the experimental results, the enhanced visible light responsive performance originates from the rich OVs introduced by the modification of BiOCl with DGBC and the higher separation rate of photoexcited carriers.
查看更多>>摘要：? 2021 The Korean Society of Industrial and Engineering ChemistryFlexible barrier films preventing corrosion are important for many industries ranging from engineering to medical to electronic materials. It is necessary to improve the corrosion resistance of aluminum alloys. The aluminum alloy sample reacted with sodium hydroxide was immersed in a double -[3-(triethoxylated) silicon-propyl] tetrasulfide and graphene（BTESPT/rGO) and cured in an oven at 100 °C to prepare a BTESPT/rGO composite film and discuss its film forming mechanism. The results shown that the film was dense and hydrophobic, which helped to improve the barrier properties of the film to corrosive ions, and its corrosion resistance was significantly better than that of a single BTESPT film. The corrosion current density of the BTESPT/rGO composite film was three orders of magnitude lower than that of the aluminum alloy substrate. The 240 h salt spray experiment shown that the BTESPT/rGO composite film greatly improved the corrosion resistance of the aluminum alloy substrate.
查看更多>>摘要：? 2021 The Korean Society of Industrial and Engineering ChemistryTissue engineering approaches using a single stem cell type have been unsuccessful in achieving regeneration of radiation-damaged salivary glands (SGs). Therefore, we combined adult SG stem cells (SGSCs) and adipose-derived stem cells (ASCs) in optimized spheroids to enhance the regeneration of damaged SGs in mice. SGSC/ASC spheroids survived longer and secreted more vascular endothelial growth factor (VEGF) than did SGSC spheroids. To enhance cell viability and differentiation, SGSC/ASC spheroids were stimulated with the Wnt/β-catenin signaling activator CHIR99021 and retinoic acid inhibitor BMS431 to maintain stemness. FGF7/10 induced the differentiation of multiple stimulated SGSC/ASC spheroids. SGSC/ASC spheroids exhibited improved viability, calcium channel function, differentiation, and VEGF secretion after multiple, sequential stimulation. The 21-day survival rate of multiply stimulated SGSC/ASC spheroids was two-fold that of non-treated SGSC/ASC spheroids. Optimized SGSC/ASC spheroids enhanced the in vivo regeneration and functional recovery of SG tissue in mice by promoting neovascularization. Genes related to VEGF, such as Vegfa and Vegfb, were highly expressed 2～6 times for in vitro and 1.5 times for in vivo experiment in the multiply stimulated SGSC/ASC spheroids. Therefore, SGSC/ASC spheroids that have undergone multiple stimulation may be useful for healing radiation-damaged SGs.
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