查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryTitanium dioxide nanoparticles (TiO2NPs) were produced using a crud flavonoid luteolin (LT) by the green process. Physicochemical characterizations of LT mediated synthesis of TiO2NPs (LT-TiO2NPs) were analyzed by different techniques. The biocompatibility of LT-TiO2NPs was evaluated by assessing their cytotoxicity, inhibition of protein denaturation, hemolysis effects, and membrane stabilization activity. The synthesized LT-TiO2NPs exhibited mostly rod-shaped morphology, rutile crystalline structure with length about 33.3–135 nm and width in 16.6–58 nm. Under LT-TiO2NPs treatments, the cell viability of cancer cells was decreased in a dose-dependent manner. According to the results, the IC50 values of LT-TiO2NPs were between 12.5–25 μg/mL for A375 and MCF-7 cancer cells, and its value was below 50 μg/mL for skin fibroblast. These NPs also induced intracellular reactive oxygen species (ROS) generation and caused mitochondrial disruption in cancer cells, leading to the induction of intrinsic apoptosis. These biosynthesized NPs did not show denaturation of bovine serum albumin (BSA) protein and hemolytic or heat-induced hemolytic effects, which confirmed their membrane stabilization activity without damaging red blood cells (RBCs) membrane integrity. Therefore, this research provides valuable results in the case of green synthesis of LT-TiO2NPs and their specific properties, biocompatibility, and their potential to be used in biomedical fields.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryChemical mechanical planarization (CMP) is indispensable for processing of integrated circuit semiconductor devices to attain globally planarized surfaces. One of the critical consumables in the CMP process is a slurry containing abrasives like colloidal silica (SiO2). However, there is a limit to the use of CMP slurries containing SiO2 under acidic conditions due to deterioration of colloidal stability, resulting in defects on the planarized surfaces. Herein, we developed an Fe-substituted SiO2 consisting of single-atom Fe(III), enabling improved colloidal stability over universal pH regions for low-defect tungsten CMP applications. The facile and unique single-atom modification process is proposed by controlling the lattice dissolution–reprecipitation replacement of Fe3+ and Si4+ ions. The physicochemical states of Fe atoms in the surficial lattice of Fe-substituted SiO2 were confirmed through Raman spectroscopy, electron microscopy, x-ray absorption spectroscopy, and energy-dispersive x-ray spectroscopy. Consequently, enhanced performance in W CMP was achieved using Fe-substituted SiO2. Regarding defect performance, defects were reduced from 11 scratches to 0 and 94 other defects to only 7. Additionally, the removal rate increased from 67 to 122 ?/min, and the surface topography improved from 6.6 to 2.9 nm.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryThe strong band-to-band visible light absorption obtained by changing the bandgap of photocatalysts is desirable but challenging for TiO2. In this paper, a mechanochemical pre-reaction and subsequent heat-treatment process were used to create TiO2/g-C3N4 heterojunctions. Acid-treated H2Ti3O7 nanobelts and superior thin g-C3N4 nanosheets (CN) were ground evenly and further heat-treated to grow rhombic TiO2 in situ on the nanosheets. The heterojunctions exhibited a band gap with the absorption in visible light region. Heterojunction formation effective tunes the surface and electronic structures of the composite, resulting in significant decrease of bandgap. g-C3N4-based heterojunctions (5TCN) exhibited excellent H2 generation (4991 μmol/g/h) and NO removal. In contrast, a TiO2-based composite (95TCN) revealed efficient photo reduction of Cr(Ⅵ) which was 2 times of that of TiO2 sample and 22 times of that of CN. The photochemical reaction mechanism of TiO2 and g-C3N4-based composites was discussed with the ratio of TiO2 and g-C3N4. The excellent performance is ascribed to single crystal rhombic TiO2 nanoparticles grown in situ on g-C3N4 to form well-developed heterojunctions which accelerate the carrier transfer. These results inspire the electronic structure engineering of photocatalysts to improve visible light absorption and provide a magic strategy for excellent photochemical activities.
查看更多>>摘要：? 2022A novel highly ordered network based on shed snakeskin has been employed as a sustainable/natural template, to fabricate efficient heterogeneous cobalt composite as catalyst by a nano-casting process. Characterization of the Cobalt nano-catalyst was investigated by several analysis methods including TEM, FESEM-EDS mapping, XRD, XPS, TGA, ICP, Raman, ATR, and N2 sorption and results verified the preparation of a nano-catalyst with highly ordered perforated structure, uniform pore size distribution, high surface area, and high stability. The nano-cobalt particles were uniformly disposed on the support with a particle size of about 100 nm, validated by various analysis methods. The catalytic performance of the synthesized catalyst was evaluated in the Suzuki-Miyaura reaction for Csp2–Csp2 bond formation in high yields (up to 97%) and excellent reactivity. The catalyst could also be recycled for at least 10 reaction runs without almost losing its activity (less than 10% after 10 runs).
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryA small surface-pore ultrafiltration membrane with a high surface porosity was fabricated from a polyether sulfone (PES) dope solution containing a small quantity of CaCO3 nanoparticles (nano-CaCO3), which coagulated in dilute HCl solution. During membrane formation, CO2 nanobubbles were in-situ generated to delay phase inversion, which ameliorated the membrane structure and performance because CO2 nanobubbles are amphiphobic to water and solvent. With increasing nano-CaCO3 content (from 0 to 0.15%) in the dope solution, the surface porosity and the surface-pore density of the obtained PES UF membrane were markedly increased from 1.76 to 6.50% and from 8.31 × 1014 to 5.08 × 1015 m?2, respectively. Nonetheless, the surface-pore size decreased from 13.35 to 8.29 nm, and so as the distribution. The optimal membrane exhibited a high pure water flux (698.2 L·m?2·h?1) and a high rejection to bovine serum album (>99%) with a moderate anti-fouling ability. This work would be of great significance for precision separation in biopharmaceutical, food processing, and other related applications.
查看更多>>摘要：? 2022Chlorogenic acids are formed from hibiscus (Hibiscus syriacus L.) by ester bonding of caffeic acid and quinic acid, and they have isomers named neochlorogenic acid (NCGA) and cryptochlorogenic acid (CrCGA) that are esterified on different sites of caffeic acid. Subcritical-water extraction (SWE) is an ecofriendly and highly efficient technique because it utilizes a nontoxic solvent and has a very short extraction time. Twenty different SWE conditions were applied to hibiscus, with extraction times of 10–40 min, and extraction temperatures of 110–190 °C. The concentrations of chlorogenic acid, NCGA, and CrCGA were maximal for extraction conditions of 190 °C/10 min, 110 °C/10 min, and 130 °C/40 min, respectively. The extraction efficiency varied with the extraction conditions among the three isomers due to the hydrophilicity of the hydroxyl residue depending on the steric structure, the stability of the steric structure varying with the position of the acyl group, and the isomerization caused by the reversible movement of the acyl group.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryPolydopamine (PDA) is used as a biocompatible mediator for fabricating glucose oxidase (GOx) based bioanode of enzymatic biofuel cells (EBFCs). Through the autoxidation and polymerization of dopamine monomer, spherical PDA particles are well synthesized, and their chemical and optical characteristics are verified. Although the durability of bioanode including CNT and PDA (CNT/PDA/GOx/Nafion) is poor, when catalyst including polyethyleneimine (PEI) upper layer (CNT/PDA/GOx/PEI/Nafion) is fabricated, CNT/PDA/GOx/PEI/Nafion shows excellent durability. This indicates PEI plays a critical role in suppressing the leaching out of PDA and GOx molecules. By the role of PEI, the anodic current density of CNT/PDA/GOx/PEI/Nafion (142.6 ± 1.98 μA cm?2 at 0.6 V (vs. Ag/AgCl)) is 17.3 times better than that of CNT/PDA/GOx/Nafion. When maximum power density (MPD) of EBFC using CNT/PDA/GOx/PEI/Nafion is measured, that of EBFC including membrane and platinum-based air–cathode is 552.8 ± 5.4 μW cm?2, and that of membraneless EBFC including bilirubin oxidase biocathode is 135.2 ± 5.45 μW cm?2, which is better than that of other reported EBFCs studies. This confirms that the suggested new catalyst is a viable option as bioanode for EBFC.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryThe present work aims to prepare and stabilize quercetin (Q) loaded zein colloidal nanoparticles using κ-carrageenan (KC) as a stabilizer. Antisolvent precipitation method was used to fabricate the zein-KC colloidal nanoparticles at pH 5.0. The findings revealed that the newly prepared Q-loaded zein-KC complex colloidal particles had spherical shapes, a particle size below ～300.0 nm, a high magnitude of negative zeta potential (～?45.0 mV) and encapsulation efficiency of 62.0%. The molecular interactions among zein, Q and KC in colloidal particles were confirmed by FT-IR analysis, and the combined mixture showed an amorphous diffraction pattern during the XRD analysis without revealing the crystalline peaks of Q or KC, indicating that Q was effectively encapsulated in complex colloidal particles. In aqueous environments, the anionic KC coating on the surface of zein colloidal particles modified the particulate and physicochemical properties of the encapsulated Q and enhanced its water dispersibility, thermal stability, and in-vitro release. The observed improvements were ascribed to hydrogen bonding, hydrophobic and electrostatic interactions among Q, zein, and KC. In addition, Q-loaded zein-KC complex colloidal particles demonstrated strong antioxidant activity. The results of this study revealed that, the KC coated zein colloidal particles, therefore, have great potential for use in hydrophobic nutraceutical encapsulation.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryWe propose an optical fiber-based localized surface plasmon resonance sensor to overcome limitations with hydrogen gas explosions in various types of hydrogen sensors and minimize human damage caused by exposure to hazardous environments. For selective detection of hydrogen, a simple palladium-capping process was applied on a fiber-optic localized surface plasmon resonance. After the palladium-capping, the sensor was exposed to various refractive index solutions to confirm the linearity of the response. Hydrogen gas reactivity was measured at concentrations from 0.8% to 4%; the reaction time at each concentration was observed as 116 s until the signal stabilized. The coefficient of variation (CV) and limit of detection (LOD) were calculated based on the results obtained through repeated measurements. The reproducibility was verified with an average CV of 11%. In addition, the developed sensor showed a low LOD of 0.086%. The hysteresis characteristic was observed within 1% in the output change, which was similar to the fluctuation range allowed by the light source per time. The proposed sensor based on the optical principle is expected to reduce the risk of explosions and has advantages in a simple configuration and low-cost production based on optical fiber.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryTo investigate the effect of acetic acid on the organic structure of coal, experimental studies and molecular dynamics simulations were used to jointly characterize the response mechanism of the organic structure of coal to acetic acid. The functional groups of coal after the dissolution of different concentrations of acetic acid were tested using Fourier infrared spectroscopy, and the results showed that: the sensitivity of functional groups in coal to different concentrations of acetic acid differs, and acetic acid mainly acts to break the linkage bonds between molecules and hydroxyl groups, producing a large amount of –OH; high concentrations (100% and 75%) of acetic acid react with CH2 alkanes to produce new CH2 alkanes, but low concentrations (50% and 25%) acetic acid does not undergo this reaction. In this paper, we model the solid–liquid system of coal-acetic acid reaction, simulate and characterize the reaction of bituminous coal organic structure to acetic acid, and find that: water molecules can help acetic acid molecules adsorb on the surface of coal molecules, but water molecules will occupy a large amount of space, thus affecting the adsorption of coal molecules. Most of the coal molecules have water molecules and acetic acid molecules adsorbed on the benzene ring and oxygen-containing functional group structures, while the functional groups associated with aliphatic groups in coal molecules are difficult to adsorb due to their hydrophobicity.
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