LiFePO4/C has been successfully synthesized using surfactant-assisted solid-state reaction method to investigate the effects of non-polar solvents on structural properties and electrochemical performance. Petroleum jelly, oleic acid, and sucrose were used as non-polar solvents, surfactants and carbon sources. The ratio of petroleum jelly and oleic acid were 0.5:1 (LFP A), 1:1 (LFP B), and 2:1 (LFP C). The XRD, FE-SEM, and HR-TEM results show that adding petroleum jelly in LFP C enhances crystallinity and improves the morphology of nanoplates in LiFePO4 material. The EDS and Raman Spectroscopy tests show that the higher addition of petroleum jelly increases carbon percentage and carbon layer defects. The highest Li-ion diffusion coefficient was calculated by LFP C of 4.21 × 10– 15 cm2. s−1. Furthermore, the highest discharge test results at 0.1 C of LFP A, LFP B, and LFP C were 125 mAh.g−1, 103 mAh.g−1, and 144 mAh.g−1, respectively. However, C-rate performance shows that the specific capacity of LFP A, LFP B, and LFP C at 5 C were 74 mAh.g−1, 35 mAh.g−1, and 59 mAh.g−1, respectively. The cyclability test results showed that LFP A capacity retention after testing for 100 cycles was better than LFP C, and the lowest stability was obtained by LFP B. The addition of petroleum jelly improved the performance of LiFePO4/ C but resulted in excess carbon in active material which decreased battery stability and specific capacity at high C-rate. Our results suggest that non-polar solvents can be added to LiFePO4/ C synthesis to improve electrochemical performance but less carbon chains must be chosen.

This study sought to improve the accuracy of estimating national emissions of volatile organic compounds (VOCs) from consumer solvent products (CSPs) by updating emission factors and category-specific activity data. The classification of the CSPs, which was originally proposed by the U.S. Environmental Protection Agency, was reorganized to reflect domestic consumption patterns in Korea. VOC contents, product sales, and atmospheric evaporation rates of the CSPs were analyzed for subcategories including personal care products, household products, and automotive aftermarket products to update their emission factors. Additionally, the category-specific activity data, previously based on only population statistics, were newly applied to count the characteristics of each classification, such as the number of households and the number of registered automobiles. The updated emission factors were calculated to be 1.90 kg/capita·yr for personal care products, 4.37 kg/household·yr for household products, and 2.36 kg/car·yr for automotive products. An evaluation of uncertainties revealed the limitation in the product classification, the shortage of sales data, and the lack of information on VOC contents depending on the product forms (liquid, solid, and aerosol). This study highlighted the necessity of developing detailed classification systems and standardized VOC content measurement methods, ultimately contributing to more accurate and practical assessments of VOC emissions from the CSPs.

Oxidative stress caused by reactive oxygen species (ROS) is a key mechanism of skin aging, and the use of antioxidants is an effective strategy to prevent the symptoms associated with ROS-induced skin aging. The components rich in polyphenolic compounds with antioxidative activity were identified by fractionating an aqueous ethanolic extract of Gryllus bimaculatus (AE-GBE) using solvent using hexane, chloroform, ethyl acetate, butanol, and water. Their ability to migrate H2O2-induced oxidative stress in human dermal fibroblasts (HDFs) was then evaluated. The butanol fraction of AE-GBE had the highest polyphenol content and antioxidant effect, followed by the ethyl acetate and water fractions, suggesting that the likely antioxidant components are polar components. Furthermore, the butanol, ethyl acetate, and water fractions effectively reduced intracellular ROS production and DNA damage in HDF cells caused by H2O2. Overall, these findings suggest that the butanol fraction of AE-GBE shows promise as a natural insect-derived antioxidant material, capable of suppressing oxidative stress by showing a stronger antioxidant effect under H2O2 stimulation than the other fractions.