Removal of elemental mercury by activated carbons impregnated with halogens

안정훈,배경민,김병주 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.1

In this work, gas-phase elemental mercury (Hg⁰) removal by activated carbons (ACs) impregnated with halogens (KI, KBr, or KCl), and the techniques of Brunauer-Emmett-Teller (BET) surface area, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) were used to characterize the sulfur-treated ACs. It was observed that the Hg⁰ removal efficiency of the ACs were significantly enhanced by KI, KBr or KCl modification, and the KI-ACs performed much better than the KBr or KCl-ACs under the same conditions. The adsorption capacity was found to increase with increase in adsorption temperature owing to the chemisorption nature of the impregnated with halogens. In the result, the impregnated with halogens have been found to increase the ACs mercury adsorption capacity.

Neutralizing Bacterial Spores Using Halogenated Energetic Reactions

Oliver Mulamba,Emily M. Hunt,Michelle L. Pantoya 한국생물공학회 2013 Biotechnology and Bioprocess Engineering Vol.18 No.5

The fight against biological warfare has prompted investigation of the chemistry and exothermic energy from energetic material reactions as a means for the neutralization of bacterial spores. The interaction between energetic reactions containing biocides and spore forming bacteria is not well understood. The goal of this work is to fundamentally examine the mechanisms of neutralization for Bacillus thuringiensis utilizing a halogenated energetic material reaction. Spore neutralization is attributed to a thermal effect from the reaction heat and the associated chemical influence of the halogen gas (i.e., produced from combustion). Results show heat transfer in the spore enhances the effectiveness of the halogen gas in the neutralization process and that elevated temperatures increase spore permeability, facilitating gas penetration and accelerating spore neutralization. Based on experimental results, a mathematical model was developed to predict spore behavior during reaction exposure over varying time scales. In the millisecond range, the model showed that the coupled thermal-biocidal gas mechanism will require elevated temperatures of 360oC to produce 80% neutralization in tens of milliseconds while thermal conditions alone would require nearly 1,000oC for the same neutralization. These results provide molecular-level insights into the components underpinning biological processes leading to spore neutralization.

Petrogenetic and metallogenic implications of the Late Mesozoic intrusive rocks in the Xuancheng ore district, eastern China: insight from in situ analysis of apatite

Huasheng Qi,Xiaoyong Yang,Sanming Lu,이인성,김영민 한국지질과학협의회 2022 Geosciences Journal Vol.26 No.1

The Xuancheng ore district is a newly discovered ore district within the Middle–Lower Yangtze River Metallogenic Belt (MYRMB) of Eastern China. Here we investigated the major and trace element concentrations of apatite crystallizes in ore-related intrusions from three skarn deposits with distinctive metal endowments in this region to further reveal their implications for petrogenesis, metallogenesis, and potential for polymetallic mineralization. The studied apatite samples identified as fluorapatite, display identical contents of F (2.04–3.25 wt%), whereas distinctive variations of Cl (0.04–1.42 wt%). The different correlations between Sr contents and (La/Yb)N, (La/Sm)N, and (Sm/Yb)N reflect the differentiation process of the magma evolution in the Xuancheng area. Furthermore, the negative Eu/Eu* and Ce/Ce* correlation, and high log fO2 values (–10.02 to –17.40) of apatite studied, further indicate more oxidized and moderate oxidized environments. Apatite chemistry is characterized by LREE enriched patterns and has high (La/Yb)N ratios with a moderate negative Eu anomaly, suggesting that these plutons originated from enriched mantle mixing with various degrees of crustal components. Meanwhile, the visible differences in apatites among skarn Cu fertile, Cu-Mo fertile, and Cu-W fertile plutons were attributed to distinctive source affinities that ultimately control their metal endowments. Also, our study demonstrates that the Cl, F/Cl, and Eu/Eu* ratios in apatite can act as powerful pointers for ore varieties and mineral exploration.

Distribution of Bromine and Iodine in Volcanic Ash Soil Profiles in Relation to Soil Properties

Akira Takeda,Atsushi Nakao,Shin-Ichi Yamasaki,Noriyoshi Tsuchiya 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

헬륨 가스 플로우와 가스 펄스 젯에서 할로겐족 원소들의 레이저유도 플라즈마 방출 스펙트럼

이용훈(Yonghoon Lee),최대웅(Daewoong Choi),공용득(Yongdeuk Gong),남상호(Sang-Ho Nam),나창운(Changwoon Nah) 한국분석과학회 2013 분석과학 Vol.26 No.4

Chlorination of Polymer Backbone for Efficient Polymer Solar Cells

김영훈,전성재,문두경 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

Bulk heterojunction polymer solar cells (PSCs) have attracted much attention because of their mechanical flexibility, light weight and low cost. Recently, PSCs consisting of fluorine have been reported to exhibit accelerating electron transfer lead to high power conversion efficiencies (PCEs) due to their high electron negativity. In addition, it has an advantages to provide more planar backbones and exhibit lowering the highest occupied molecular orbital (HOMO) levels. However, fluorinated polymers have some problems such as severe aggregation and low yields of fluorine exchange. So, we need chlorination to overcome disadvantages instead of fluorination. In the study, we synthesized and designed a chlorinated donor-acceptor (D-A) polymer. Chlorinated polymer showed high yield in overall synthesis steps and affordable crystallinity with blended non-fullerene acceptors. These results demonstrate that chlorination is promising method to reach the high PCEs of PSCs.

Edge-halogenated graphene nanoplatelets with F, Cl, or Br as electrocatalysts for all-vanadium redox flow batteries

Park, Minjoon,Jeon, In-Yup,Ryu, Jaechan,Jang, Haeseong,Back, Jong-Beom,Cho, Jaephil Elsevier 2016 Nano energy Vol.26 No.-

<P><B>Abstract</B></P> <P>The catalytic activity of V<SUP>2+</SUP>/V<SUP>3+</SUP> and VO<SUP>2+</SUP>/VO<SUB>2</SUB> <SUP>+</SUP> redox couples on the halogen-doped graphene nanoplatelets (F-, Cl-, and Br-GNPs) is studied by ball-milling graphite flakes with fluorine (F<SUB>2</SUB>), chlorine (Cl<SUB>2</SUB>), and bromine (Br<SUB>2</SUB>) molecules, respectively. Using the edge-selectively halogenated graphene materials with different edge exfoliation degrees, the vanadium redox reactions can be significantly facilitated by having abundant edge defects with large surface area in the order: Br-GNP>Cl-GNP>F-GNP. The influence of halogen functionalization on graphene nanoplatelets towards vanadium redox couples is further confirmed by stack-type vanadium redox flow batteries that demonstrates better cell performance than graphene nanoplatelets without dopant at the edges. Notably, the Br-GNP showed unique electrochemical performance of increased initial charge/discharge capacity and improved rate capability, respectively. It was found that halogen doping on graphene-based materials can promote vanadium redox reactions by creating effective active sites, and the electrocatalytic activity is dependent on edge exfoliation degree and well-preserved basal planes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Edge-halogenated graphene nanoplatelets for vanadium redox reactions was studied. </LI> <LI> Halogen doping on graphene-based materials can promote vanadium redox reactions. </LI> <LI> A large degree of edge exfoliation by Br facilitates mass transport of vanadium ions. </LI> <LI> Br-GNP catalyst leads to decrease of cell overpotentials in VRFBs. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Two-dimensional networks of brominated Y-shaped molecules on Au(111)

Jeon, Un Seung,Chang, Min Hui,Jang, Won-Jun,Lee, Soon-Hyung,Han, Seungwu,Kahng, Se-Jong Elsevier 2018 APPLIED SURFACE SCIENCE - Vol.432 No.2

<P><B>Abstract</B></P> <P>In the design of supramolecular structures, Y-shaped molecules are useful to expand the structures in three different directions. The supramolecular structures of Y-shaped molecules with three halogen-ligands on surfaces have been extensively studied, but much less are done for those with six halogen-ligands. Here, we report on the intermolecular interactions of a Y-shaped molecule, 1,3,5-Tris(3,5-dibromophenyl)benzene, with six Br-ligands studied using scanning tunneling microscopy (STM). Honeycomb-like structures were observed on Au(111), and could be explained with chiral triple-nodes made of three Br···Br halogen bonds. Molecular models were proposed based on STM images and reproduced with density-functional theory calculations. Although the molecule has six Br-ligands, only three of them form Br···Br halogen bonds because of geometrical restrictions. Our study shows that halogenated Y-shaped molecules will be useful components for building supramolecular structures.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We studied intermolecular interactions of a Y-shaped molecule, 1,3,5-Tris(3,5-dibromophenyl)benzene, with six Br-ligands using scanning tunneling microscopy. </LI> <LI> Honeycomb-like structures were observed on Au(111), and could be explained with chiral triple-nodes made of three Br···Br halogen bonds. </LI> <LI> Molecular models were proposed based on STM images and reproduced with density-functional theory calculations. </LI> <LI> Our study shows that halogenated Y-shaped molecules will be useful components for building supramolecular structures. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Halogen-Free 난연제를 포함하는 파우더 코팅소재 제조 및화재안전성 연구

이순홍,정화영,김대인,노태준 한국안전학회 2011 한국안전학회지 Vol.26 No.4

Halogen free intumescent flame retardants(IFRS), such as the mixture of melamine phosphate(MP) and char forming agents(pentaerythritol(PER), di-pentaerythritol(DiPER), tris(2-hydroxyethyl) isocyanurate(THEIC)), were prepared and characterized. Polypropylene(PP)/IFRS composites were also prepared in the presence of ethylene diamine phosphate(EDAP) as a synergist and used into flame retardant PP powder coatings. Thermoplastic PP powder coatings at 20 wt% flame retardant loading were manufactured by extruded and then mechanical cryogenic crushed to bring them in fine powder form. These intumescent flame retardant powder coatings(IFRPCS) were applied on mild steel surface for the purpose of protection and decorative. It is a process in which a IFRPCS particles coming in contact with the preheated mild steel surface melt and form a thin coating layer. The obtained MP flame retardant was analyzed by utilizing FTIR, solid-state 31P NMR, ICP, EA and PSA. The mechanical properties as tensile strength, melt flow index(MFI) and the thermal property as TGA/DTA and the fire safety characteristics as limiting oxygen index(LOI), UL94 test, SEM were used to investigate the effect of IFRPCS. The experimental results show that the presence of IFRS considerably enhanced the fire retardant performances as evidenced by the increase of LOI values 17.3 vol% and 32.6 vol% for original PP and IFRPCS-3(PP/MP-DiPER/EDAP), respectively, and a reduction in total flaming combustion time(under 15 sec) in UL94 test of IFRPCS. The prepared IFRPCS-3 have good comprehensive properties with fire retardancy 3.2 mm UL94 V-0 level, LOI value 32.6%, tensile strength 247.3 kg/cm2, surface roughness Ra 0.78 µm, showing a better application prospect. Through IFRPCs-2(PP/MP-PER/EDAP) and IFRPCs-3 a better flame retardancy than that of the IFRPCs-1(PP/MP/EDAP) was investigated which was responsible for the formed more dense and compact char layer, improved synergy effect of MP and PER/DiPER.

The Detection Distance of Colored Target using Various Automotive Headlamps

Jung Yong Kim,Ho Sang Lee,Seung Nam Min,Min Ho Lee 대한인간공학회 2012 大韓人間工學會誌 Vol.31 No.3

Objective: As headlamp technology advances, newly developed various headlamps were introduced in the market. The objective of this study is to quantitatively analyze the detection distance of the recently developed LED headlamps and existing headlamps, complying with specific technical standard. Background: The detection distance of headlamps is very important to prevent automobile accident at night time. The studies of detection distance of LED, Halogen and HID headlamp have been conducted, but no study has shown the detection distance of pedestrian target with various colors (Black, White, Blue). Method: The experiment of detection distance was conducted with 30 people, which divide into 2 groups as 15 men and 15 women. Automatic transferable target on the rail was manufactured in order to reduce the error of study"s result, and ANOVA also conducted to analyze the main effect with sign color, sex and headlamp classified by detection distance. In addition, the luminance by average detection distance was measured as well. Results: The detection distance of headlamps was HID > LED > Halogen. The luminance measure of LED headlamp was lower than HID and Halogen headlamps. Conclusion: The headlamp performs a very significant role for safety at night time but it needs to be improved through assessment of visual characteristics. Also, it needs to be suggested the need of test method for dynamic detection distance concerning technical development is suggested.