• Applied Chemistry for Engineering
• /
• v.33 no.6
• /
• pp.630-635
• /
• 2022

Copper(II) oxide (CuO), electroless plated on a nitrogen-containing carbon sponge prepared by a melamine sponge thermal treatment, was developed as a nitric oxide (NO) gas sensor that operates without a wafer. The CuO content on the surface of the carbon sponge increased as the plating time increased, but the content of nitrogen known to induce NO gas adsorption decreased. The untreated carbon sponge showed a maximum resistance change (5.0%) at 18 min. On the other hand, the CuO plated sample (CuO30s-CS) showed a maximum resistance change of 18.3% in 8 min. It is considered that the improvement of the NO gas sensing capability was caused by the increase in hole carriers of the carbon sponge and improved movement of electrons due to CuO. However, the NO gas detection resistance of the CuO electroless plated carbon sponge for 60 s decreased to 1.9%. It is considered that the surface of the carbon sponge was completely plated with CuO, resulting in a decrease in the NO gas adsorption capacity and resistance change. Thus, CuO-plated carbon sponge can be used as an effective NO gas sensor because it has fast and excellent resistance change properties, but CuO should not be completely plated on the surface of the carbon sponge.

• Composites Research
• /
• v.36 no.3
• /
• pp.217-223
• /
• 2023

In this work, the preparation and its oil adsorption behavior of polyacrylonitrile-based carbon nanofiber sponge were investigated. The prepared carbon sponges showed excellent selective oil adsorption in the mixture of water and oil, and the adsorption capacity of reused carbon nanofiber sponge was also investigated. Further, carbon nanofiber sponge adsorbent with internally structured channel showed fast oil adsorption behavior due to a capillary phenomenon. After use, sponge adsorbent was heat-treated at 800℃ under N² and studied the possibility of a sensor for electrochemical detection of 4-aminophenol.

• Membrane and Water Treatment
• /
• v.12 no.2
• /
• pp.65-73
• /
• 2021

Sponge ball cleaning can generate an abrasion effect, which leads to an attractive increasing in both permeate flux and membrane rejection. The aim of this study was to investigate the influence of the daily sponge ball cleaning (SBC) on the performance of different UF cross-flow membrane modules integrated with a bioreactor. Two 1"-membrane modules and one 1/2"-membrane module were tested. The parameters measured and controlled are temperature, pH, viscosity, particle size, dissolved organic carbon (DOC), total suspended solids (TSS), and permeate flux. The permeate flux could be improved by 60%, for some modules, after 11 days of daily sponge ball cleaning at a transmembrane pressure of 350 kPa and a flow velocity of 4 m/s. Rejection values of all tested modules were improved by 10%. The highest permeate flux of 195 L/㎡.h was achieved using a 1"-membrane module with the aid of its negatively charged membrane material and the daily sponge ball cleaning. In addition, the enhancement in the permeate flux caused by daily sponge ball cleaning improved the energy specific demand for all tested modules. The negatively charged membrane showed the lowest energy specific demand of 1.31 kWh/㎥ in combination with the highest flux, which is a very competitive result.

• Carbon letters
• /
• v.18
• /
• pp.71-75
• /
• 2016

• Journal of the Korean Electrochemical Society
• /
• v.27 no.1
• /
• pp.47-54
• /
• 2024

In this study, ZIF67/rGO was used to minimize the battery life degradation due to the insulating properties of sulfur and the elution of lithium polysulfide. ZIF67 wrapped in rGO creates more space within the carbon sponge and can hold a large amount of sulfur. The sulfur@ZIF67/rGO composite was synthesized and prepared as a sponge to enhance the sulfur retention capacity. The result showed a high initial capacity, with a value of about 1093 mAh g^-1 and a capacity retention rate of 84% after 100 cycles. The high interaction with sulfur through the complexation of cobalt and carbon confirmed that ZIF67/rGO exhibits high performance as a carrier for sulfur, the anode active material of lithium-sulfur batteries, and the high initial capacity and improved capacity retention rate were confirmed.

• Journal of Korean Society of Water and Wastewater
• /
• v.26 no.6
• /
• pp.883-888
• /
• 2012

Anode electrode is one of the most important factors in microbial fuel cell (MFC). This study was conducted to investigate the effects of mediator as methylene blue (MB) and electrode surface area on the power density of MFC with sponge and carbon nano tube (CNT) electrode (SC). The SC electrode with MB (MC) showed the maximum power density increased from 74.0 $mW/m^2$ to 143.1 $mW/m^2$. The grid shaped sponge and CNT (GSC) electrode showed the maximum power density of 209.2 $mW/m^2$ due to the increase of surface area from 88.0 to 152.0 $cm^2$. The GSC electrode with MB (GMC) revealed the maximum power density of 384.9 $mW/m^2$ which was 5.2 times higher than that obtained from the MFC with SC. Therefore MB and increase of surface area led to enhance the performance of microbial fuel cell such as power density.

• Journal of the Korean Magnetic Resonance Society
• /
• v.25 no.2
• /
• pp.24-32
• /
• 2021

Two new sesterterpenes, including a known sesterterpene, were isolated from the marine sponge Haliclona sp. collected in the Gageo island, Korea. One of the new sesterterpenes (1) was an unusual compound possessing a spiroketal moiety and the other (2) represented a four ring-fused skeleton. The planar structure of compound 1 was identical to gombaspiroketals A and B isolated from the marine sponge Clathria gombawuiensis, but the configuration for the two chiral centers was different each other. On the other hand, the skeletal structure of compound 2 was similar to that of phorone A isolated from Phorbas sp. and a compound from C. gombawuiensis, except for one configuration at C-8. However, in comparing the ¹H and ¹³C NMR spectral data, the proton and carbon chemical shifts for the three compounds were almost consistent. The NOESY spectrum revealed that the C-8 configuration of 2 was reversed to that of the two reported compounds. The configuration for compound 2 was supported by quantum mechanical calculation for the carbon chemical shifts and DP4+ probability for the protons and carbons of 2.

• Korean Journal of Environmental Biology
• /
• v.27 no.3
• /
• pp.244-251
• /
• 2009

To assess the algicidal effect of a bacterium, Pseudomonas fluorescens HYK0210-SK09 (SK09), attached to activated carbon polyvinyl alcohol (ACPA) and cellulose sponge (CS) carriers against Stephanodiscus hantzschii, the present study was carried out in an indoor-microcosm. As comparing immobilization effects of two carriers, the ACPA carrier allowed for higher packing cell density of SK09 compared to the CS carrier. In the microcosm, immobilized SK09 cells were applied to control S. hantzschii blooms. Immobilized SK09 cells exhibited a species-specific activity towards the diatom, showing an algicidal effect up to 72% attached by ACPA carriers and to 51% attached by CS carriers. In particular, a level of conductivity treated with ACPA carriers was decreased than that of CS carriers. The present study clearly demonstrates that ACPA-immobilized SK09 cells could effectively control S. hantzschii blooms and improve water quality in the microcosm ecosystem.

• Journal of the Korean Magnetic Resonance Society
• /
• v.17 no.1
• /
• pp.47-53
• /
• 2013

Four new cyclic peroxide compounds (1~4) were isolated from the marine sponge Plakortis simplex. Their structures including relative stereochemistry were determined by MS and NMR analysis. All compounds, a side carbon chain with 10 carbons, were very unstable. After transformation into methyl ester analogues, the structure determination was conducted. Compounds 1a and 2a are stereoisomers, assigned as $3S^*$, $4S^*$, $6R^*$ and $3R^*$, $4S^*$, $6R^*$, respectively. Similarly, compounds 3a and 4a, replaced the methoxy group with an aliphatic methyl, are also stereoisomers. Compounds 1a and 2a exhibited the strong antifungal effect against the fungus Candida albicans.

• Journal of Korean Society for Atmospheric Environment
• /
• v.25 no.3
• /
• pp.237-247
• /
• 2009

The combustion characteristics of car components have been investigated, The combustion parameters like heat release rate, smoke production, yield of carbon dioxide and carbon monoxide and mass loss rate were analyzed by cone-calorimeter for representative samples (seat, carpet, headrest, rubber mat, dash board and electric wire) collected from a used car. The results from sample combustion showed that cover and sponge in seat more quickly ignited and flamed than other parts. The heat released from the combustion of dash board sample was 144.29$kw/m^2$ and the smoke produced by the wire combustion was 6896.4 $m^2/m^2$. The yields of carbon dioxide and carbon monoxide were in the ranges of 1.09${\sim}$2.76 kg/kg and 0.0262${\sim}$0.1008 kg/kg, respectively.